Jump to content

Wikipedia:Reference desk/Computing

Add links
From Wikipedia, the free encyclopedia
< Wikipedia:Reference desk

This is an old revision of this page, as edited by 83.98.238.113 (talk) at 21:12, 29 July 2009 (→‎Plucker and Ebook readers). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Welcome to the computing section
of the Wikipedia reference desk.
skip to bottom
Select a section:
Shortcut
Want a faster answer?

Main page: Help searching Wikipedia

   

How can I get my question answered?

  • Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
  • Post your question to only one section, providing a short header that gives the topic of your question.
  • Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
  • Don't post personal contact information – it will be removed. Any answers will be provided here.
  • Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
  • Note:
    • We don't answer (and may remove) questions that require medical diagnosis or legal advice.
    • We don't answer requests for opinions, predictions or debate.
    • We don't do your homework for you, though we'll help you past the stuck point.
    • We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.


Ready? Ask a new question!


How do I answer a question?

Main page: Wikipedia:Reference desk/Guidelines

  • The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.
See also:



July 22

Red channel on data projectors broken?

I've come across many many projectors in our (national) company that don't display colours correctly. Without exception it is the red channel that seems to be broken. On Saturday I picked up the same phenomenon on another projector (different brand, different organisation completely). My google-fu is not strong enough to find a discussion about this on the web. What could be happening? Is it a known problem with the red channel on data projectors? AFAIK they are all DLP projectors rather than LCD. They are basically now unusable for movies or photos, only presentations. Even then you have to choose your colours carefully. The problem is so bad that we've been instructed to differentiate our graphs by some mean other than purely colour. The projectors are generally older than 1 year but <3 years. What the hell is going on? Zunaid 07:50, 22 July 2009 (UTC)[reply]

There's several reasons why a projector wouldn't show red, have you tested different input ports? Has the red channel gone all black or all white? --66.195.232.121 (talk) 20:17, 22 July 2009 (UTC)[reply]
It goes all black. The red channel simply doesn't display so the image is made up of only the B and G. The phenomenon happens at work with VGA-VGA cable as well as with the other projector with a DVI input using a VGA-DVI connector. Different user, different PCs at work, same result. It really is so common that I thought Google would bring something up, but sadly no. Zunaid 20:53, 22 July 2009 (UTC)[reply]

Need help with document.body.style.cursor!

document.body.style.cursor = 'crosshair' (or one of the common cursors, like "hand" or "help") works, but changing "crosshair" to an image URL to get a custom cursor does not work! I also tried document.body.style.cursor = 'url(the_image_URL_here)'. I have checked many times and the image URL is correct. How do I get it to work? —Preceding unsigned comment added by 59.189.59.132 (talk) 10:40, 22 July 2009 (UTC)[reply]

Quirksmode says IE needs a .cur image, rather than taking an jpeg or png. I think a .cur is a .ico. 87.113.21.118 (talk) 10:58, 22 July 2009 (UTC)[reply]

Thanks!!! How do I convert a bmp, jpeg or gif image to a cur image? Any other stumbling blocks to note?

Cur is an ICO that has a hotspot, I believe. You need specialized software for it. Google "create windows cursor." --98.217.14.211 (talk) 13:33, 22 July 2009 (UTC)[reply]
I like the free AniFX software. --Andreas Rejbrand (talk) 22:39, 22 July 2009 (UTC)[reply]

Does anyone know an online collection of cursors which I can use with document.body.style.cursor? —Preceding unsigned comment added by 59.189.62.31 (talk) 08:02, 23 July 2009 (UTC)[reply]

Where can I find a good Ghostscript tutorial?

Hello. I'm looking for a tutorial on how to use the Ghostscript interpreter interactively. The only information I've been able to find is on how to run the gs command in batch mode. But I want to enter in PostScript one line at a time. I can't find a list of commands supported by Ghostscript and what the prompts mean (e.g., I often see a <1> or something similar after gs>). I found a very basic introduction with a hello-world example, but that's it so far. It just seems that no one is interested in PostScript any more. I don't understand why. Sigh.--H. Gutmans (talk) 11:18, 22 July 2009 (UTC)[reply]

It's not that no one is interested in post script, it's that there are libraries that vastly, vastly simplify things, so you don't have to muck around at such a low level. --98.217.14.211 (talk) 13:37, 22 July 2009 (UTC)[reply]
Postscript is actually a fully respectable programming language - comparable in many ways to Python. It's more or less a matter of history that's relegated it to the rather odd niche of becoming a language for sending stuff to printers and such. We used to have entire windowing systems written using it (see NeWS). Sadly, I've forgotten all the Postscript I ever knew. As far as I know, if you fire up 'gs' without parameters then you can basically type Postscript programs right there at the 'gs>' prompt. But gs isn't a full development system with editing and all that good stuff. You really need to type your programs in someplace else and launch them from within gs. SteveBaker (talk) 04:36, 23 July 2009 (UTC)[reply]
Good points. It's used today for many things, as well. PDFs, EPS files, and Type 1 fonts are written their own dialects of PostScript. But the most-recent books on PostScript are all out of print. There's a book available for download on PS, but it's from 1990 -- before PostScript Level 2 or 3. I've been reading Adobe's PostScript reference manual, and it's very dense reading. It's harder to learn than C for me, and the lack of friendly literature isn't making it any easier.--H. Gutmans (talk) 07:16, 23 July 2009 (UTC)[reply]

print screen

how do i print screen WITH THE CURSOR?

To strictly answer your question, I was just able to do it by Clicking on 'START/All Programs/Accessories/Accessability/Onscreen Keyboard' and then slicking on the "psc" button on the onscreen keyboard.
However, when I personally need a screen shot, I tend to use the "Create/Screenshot" feature of The Gimp. (The screenshot feature is called slightly different things in different versions, but it's always easy to find.) Hope this helps. APL (talk) 13:23, 22 July 2009 (UTC)[reply]
To capture an image of the screen that also has the mouse pointer in it, you can use IrfanView, an image viewing program for Windows. In IrfanView, you can go to the Options menu and click on Capture/Screenshot. One of the options you can check is to "Include mouse cursor". --Bavi H (talk) 00:41, 23 July 2009 (UTC)[reply]
Oh. I thought he meant he wanted to use the cursor to do a print screen. Your way makes more sense. APL (talk) 00:51, 23 July 2009 (UTC)[reply]

Computer shutting down

Hello. I've had my laptop for two years and it's always worked fine. Recently though, every time I try to 'wake up' the computer from standby, I get a brief flash of blue screen of death, then the computer restarts. Otherwise, the computer is fine. I've checke dm power options, and they are set to default (I.e the power button is not set to instantly shutdown). Is there any way I can fix this problem? Many thanks in advance =) Cuban Cigar (talk) 12:24, 22 July 2009 (UTC)[reply]

Check that the battery isn't running out. This can cause the "blue screen of death". Also, check when the computer is due to sleep in power options. 90.194.115.243 (talk) 13:16, 22 July 2009 (UTC)[reply]

Ok my battery is always charged and is def not running out. In power options, system standby is set at 'never'.114.77.68.9 (talk) 13:53, 22 July 2009 (UTC)[reply]

Try turning off automatic restarts after the blue screen of death (it's somewhere in Control Panel -> Systems if I remember correctly) - the exact error message may give you a clue as to what is going wrong. — QuantumEleven 14:38, 22 July 2009 (UTC)[reply]
When the system restarts, keep pressing the F8 key. when the advanced startup options appear, select the last known good configuration, try safe mode, if it goes to safe mode, try system restore. 131.107.0.77 (talk) 13:05, 28 July 2009 (UTC)[reply]


It could be a ram issue if you are in sleep mode, could be a harddrive issue if you are in hibernation mode. In any case there is an issue with either hardware re-distributing the information stored within when your pc sleeps/hibernates Ivtv (talk) 23:30, 28 July 2009 (UTC)[reply]

Calender files

Is there an easier way to create a series of calender events than just creating them one by one using sunbird, windows calender or outlook? For example, could the events be created in an excel document and then converted to a .isc file and then imported? I know calenders can be exported into a .csv file from sunbird but I cant seem to import it back the way. I am using windows vista. 90.194.115.243 (talk) 13:11, 22 July 2009 (UTC)[reply]

A cursory Google search shows at least one entity is already doing such a thing using Google Spreadsheets. [1] . So I know it is possible. However, I am at a loss when it comes to suggesting how to do it yourself. Its a good question. Kushal (talk) 15:25, 22 July 2009 (UTC)[reply]
The ISC format is pretty open and the standard is too. I'm sure there are programs out there that do a number of things on data for it. Often it's the pain of parsing the input. What exactly are you trying to do? Shadowjams (talk) 11:31, 26 July 2009 (UTC)[reply]

Running a site from my home computer

Hey everyone! I'm thinking about running a small website from my home computer. A few people, maybe about 20 or so in total, will connect to my server and view pages just like any other website. The problem is I have an awfully slow upload speed, approximately 40KB/s at best. Will this cause a big problem for people trying to use my site? Will it be too slow?

As a test I've set up an example of what my site will be like (edit: I've removed the link because I've turned the server off). If it's not too much to ask, could somebody test the features, like loading a few images, and report back on if it's too slow to be usable? I'm also interested in any advice, experience or really anything you can share with me about running a home server as I'm very new to this.

Thanks so much for your help! —Preceding unsigned comment added by 82.43.88.29 (talk) 13:41, 22 July 2009 (UTC)[reply]

not too bad for speed, at least when I tried.83.100.250.79 (talk) 14:34, 22 July 2009 (UTC)[reply]
It worked reasonably well from here as well. You might as well give it a try. If it starts giving you problems you can switch to the cheapest hosting service you can find. APL (talk) 14:50, 22 July 2009 (UTC)[reply]
ok thanks for testing :) So does anyone have any advice for me in general about running a server from home? Anything I need to be aware of? —Preceding unsigned comment added by 82.43.88.29 (talk) 19:23, 22 July 2009 (UTC)[reply]
Just be aware of the obvious: 1. you might be violating your internet service provider's terms of usage; 2. you could easily go over quota (especially if someone gets your URL who doesn't like you and just curls the larger files on your site); 3. there are far higher consequences if it turns out your scripts have exploits in them; 4. and, uh, that probably covers it. Personally I think the standard $9/mo. hosting is a lot easier to deal with than home hosting, and of course you can use it for all sorts of projects without any difficulty. --98.217.14.211 (talk) 21:42, 22 July 2009 (UTC)[reply]
If you have limited bandwidth - then be aware that you're now sharing it with your 20 buddies. You are somewhat more noticable to evil bad guys who are intent on hacking your system. You have to leave your computer running 24/7. Having said all that - I ran my site from home for years without significant problems. Only fairly recently did I switch over to a web hosting company...which I have to say, it well worth the $10 a month it costs me. SteveBaker (talk) 04:29, 23 July 2009 (UTC)[reply]

carelessly using an USB stick

whenever I pull out a USB stick, I do not stop the device. Sometimes, I close the explorer windows showing folders inside the USB stick. I only see to it that the lights are not blinking or that I don't save or run anything from it when iam pulling it out. Will this damage the USB stick? —Preceding unsigned comment added by 131.220.46.25 (talk) 15:01, 22 July 2009 (UTC)[reply]

I doubt it will do any damage to the device itself. As for your data on the device at that time, I don't think anyone can make any promises. Kushal (talk) 15:20, 22 July 2009 (UTC)[reply]
Nobody can make promises. Modern versions of operating systems (especially Windows) have been more intelligent about directly and immediatel flushing files to the stick, and avoiding spurious reads and writes to the stick, so if you are not actively engaged in a file write operation, there "should" be no problems. However, USB is a complicated protocol, and the file system interacts with a lot of interwoven systems on your operating system, so there isn't an easy way to guarantee that file corruption will not occur. (You might be engaging in a file transfer operation, or still completing an old one that you thought was already finished, and you might not even know it). It's 8:37 AM - do you know where your bits are? The flashing LED indicators are not a guarantee of anything - some USB standards exist regarding these indicators, but I don't think they are consistently applied. Nimur (talk) 15:36, 22 July 2009 (UTC)[reply]
Are you running portable applications? If so, the risk of "damage" is increased, as these applications may write state information to the disk which they need to remove to shut down cleanly. — QuantumEleven 15:49, 22 July 2009 (UTC)[reply]
Dare I just ask why you don't bother stopping the device? It takes all of one mouse click to do so. Is it just laziness? Your subject line indicates you are aware it is careless. --98.217.14.211 (talk) 16:57, 22 July 2009 (UTC)[reply]
Actually if the folders are closed, and you're not watching a 'copying files' dialog (obviously obviously) there shouldn't be any problem at all. USB is designed for this type of thing - you should have no problems. Provided that you let files finish copying etc.83.100.250.79 (talk) 23:20, 22 July 2009 (UTC)[reply]
That's exactly the problem - "letting the files finish copying" is a misunderstanding. The operating system decides when the files are finished copying; you do not (even if the dialog or command terminal says the files are copied, there may be lower abstraction layers that have not finished the work). Some operating systems can have macroscopic delays (seconds, minutes, hours, or "never") after you do your "drag and drop" or complete your copy command, before the files are actually flushed to the hardware. Though modern systems try to avoid hanging open files around, you can't be very sure unless you know every minute detail of your OS file system handler. Nimur (talk) 01:15, 23 July 2009 (UTC)[reply]
I'm not sure that I 100% believe that, you seem to be saying that the OS would close the copying files dialog box, before it had actually copied the files, or not even copy the files at all, and what? just show a hypothetical copying dialog box with a progress baar, whilst be doing nothing? Then add the files to be copied to a list of things to do, and maybe do it later, if it feels like it?? Did you have an OS in mind? (I'm just assuming that it doesn't take a brain surgeon to work out that the dialog box doesn't close until the process has finished. Wouldn't the programmer have to be noticebly stupid to do something like that)
There might be an issue with cached flash though, I suppose...(I should mention that)83.100.250.79 (talk) 01:58, 23 July 2009 (UTC)[reply]
That is exactly what I am saying, and yes, it is allowable under certain circumstances. The modern file systems in use on a modern operating system are very complicated. That is why the "Safely Remove Hardware" ever needed to exist in the first place. Yes, you are right - it would be very rare to have the copy-dialog close several hours before the file flushes, but most of the file systems I've ever worked with are designed with event-driven programming - this means that there is absolutely no time constraint, ("wall clock" time), before certain processes complete. I can think of a variety of scenarios which obfuscate the simple transactional "open file - edit file - save file" model. What if two programs are editing the same file, and they both operate an auto-save feature, and each has a modified version of the same file? When does the operating system actually write the bits to the harddisk or USB stick? What if it is the same program, with multiple lightweight threads? (... or multiple hardware threads?) ... (or system interrupts that perform file writing?) What about programs that write scratch-files to (poorly-chosen) locations on the USB stick? A file transfer may be in process at any time. All of these pathological cases do exist, and modern operating systems may choose to handle them in complicated ways. Nimur (talk) 15:06, 23 July 2009 (UTC)[reply]
I'm assuimg there are just files on there, and not say an OS.83.100.250.79 (talk) 23:22, 22 July 2009 (UTC)[reply]

If you want to pull the usb out quick (assuming you're on windows) makes sure you have (starting by selecting the usb stick or whatever in mycomputer) : Rightclick, properties, hardware, (select the device), then properties, policies, and select "optimise for quick removal" - that way if any copies are finished, you should be able to remove the device without having to use "safely remove hardware". I should have mentioned that.83.100.250.79 (talk) 02:33, 23 July 2009 (UTC)[reply]

NOTE, as described above - this is only safe to do if you are only using 'it' for saving files initiated by you, if the computer has any automated backup file programs running that us the memory stick, then it's safest to use the remove hardware button.
However in windows, with "optimise for quick removal" set to on, and using the thing as a disk drive in which only you get to save files to it (manually) you are ok. But if the remove hardware button is showing - you should use it..83.100.250.79 (talk) 16:57, 23 July 2009 (UTC)[reply]
On Windows, I personally find it easier to left click and click the drive that I need to remove. But that's just me. :) Kushal (talk) 18:14, 24 July 2009 (UTC)[reply]

[Perl] I hate this nasty animal

Perl seems to have many nasty internal inconsistencies. For example, some functions affect its own argument(s) whiles many others don't.

If you want to delete the ending \n character:

  • Correct: chomp($string);
  • Error: $string = chomp($string);

However, if you want to reverse an array:

  • Error: reverse(@array);
  • Correct: @array = reverse(@array);

Why did they create this obvious bug? -- Toytoy (talk) 16:29, 22 July 2009 (UTC)[reply]

It's not a bug it's a feature. I don't use perl too much. --91.145.73.217 (talk) 17:34, 22 July 2009 (UTC)[reply]
I suspect is has to do with how different object types are actually handled in memory, though that is just a conjecture. Anyway, most languages I have used do something like this on a regular basis; it's not unique to Perl. --98.217.14.211 (talk) 18:15, 22 July 2009 (UTC)[reply]
Yes, non systematic syntax is probably the name for it, and I too have seen such annoying things in other languages (including pascal, where I didn't expect it - used for teaching and all that...)
I've you want sympathy - I've have lots for you, it's a total pain. There's no excuse for a non-orthogonalnot sure orthogonal is the right word language.
Maybe learn something else??83.100.250.79 (talk) 23:18, 22 July 2009 (UTC)[reply]
I guess it comes from different programmers writing the extensions - one has made the 'function' as a function, the other as a proceedure - same problem I experienced - I'd guess since there are no proceedures as such in C (which perl is written in I understand), that chomp(string) returns null (someone else may be better to explain)
Alternatively it could be, as described above - a feature - based on expectations of whether the original string is expected to be wanted to be kept unharmed. Which makes vague sense in the examples, but not much.
83.100.250.79 (talk) 00:00, 23 July 2009 (UTC)[reply]

Personally, I find the basic syntax of functions not quite intuitive when they are nested. For example, you may want to paint your wall, so you ...

  1. Add water to your paint.
  2. Dip your brush into the paint bucket.
  3. Apply the paint to the wall.

$painted_wall = apply(dip($brush, mix($paint, $water)), $wall);

The whole thing is very difficult to read (i.e., the reading direction is zigzagged). You can use more intermediate variables, but they make your code longer and more difficult to remember variable names.

$painted_wall = &apply(&dip($brush, &mix($paint, $water)), $wall);

I prefer to use the old-fashioned & prefix for functions. This prefix and the use of parenthesis is against the teaching of the animal-covered book Perl: The Best Practices. There is no way to do nested functions without enclosing the arguments in parenthesis unless you want to write your program in FORTH.

Is there a systematic way to deal with these annoying things? -- Toytoy (talk) 00:27, 23 July 2009 (UTC)[reply]

Did you mean in perl, or in general. Your request looks vaguely like a plea for an object orientated language, but I'm not convinced that would turn out to be a better solution (due to the same sort of niggles as before.)83.100.250.79 (talk) 02:01, 23 July 2009 (UTC)[reply]

Creative SB Audigy 2 (WDM) SPDIF

Forgive my ignorance and incompetence regarding this subject. I have a Creative SB Audigy 2 (WDM) soundcard. According to my Control Panel, this card apparently supports SPDIF out, which would be awesome because I'd like to connect it to my receiver for at least 5.1 surround sound. I pulled out my computer and checked the soundcard jacks, but I couldn't find any digital (optical or coaxial) output jacks :(. How do I get digital sound out to my receiver? Thanks for the help!! --71.117.39.22 (talk) 16:49, 22 July 2009 (UTC)[reply]

Is this an add-on card? Is this a laptop or PC; which model? If it is built into the PC, then the SPDIF connector may be an option. ---— Gadget850 (Ed) talk 17:04, 22 July 2009 (UTC)[reply]
Okay here comes the incompetence...but let me have a shot at this. It's in a desktop (the easy one). I think it's an add-on; it is in a PCI slot. I'm running a dual boot Vista/XP OS. I think SoundMAX is the integrated audio from the motherboard (it doesn't work anyway). What else do you need to know? --71.117.39.22 (talk) 17:15, 22 July 2009 (UTC)[reply]
Ok is it a "creative audio sound blaster audigy 2" ie like these http://images.google.co.uk/images?hl=en&q=Creative%20Sound%20Blaster%20Audigy%202&um=1&ie=UTF-8&sa=N&tab=wi ie does the external plate connections look the same - there doesn't seem to be a standar spdif out on these..but - from here http://www.twenga.co.uk/specs-Sound-Blaster-Audigy-2-ZS-CREATIVE-LABS-Sound-card-1283 the specs mention a "1 x audio - SPDIF output - mini-phone 3.5mm" - I've come across these before - it's a 3.5mm socket (as in miniheadphone etc), but at the end there is the optical out (sony used to put these in their minidiscs) - it's a dual use socket. You need a 3.5mm optical to spdif connector - there are some here (less than £10) [2] they're actually quite common. You can even get adaptors [3]. I've assumed it's optical digital out, not electrical.
Also see Mini-TOSLINK , and the references to mini-TOSLINK in TOSLINK.
All you need to work out is which socket... Have you got the manual?83.100.250.79 (talk) 23:09, 22 July 2009 (UTC)[reply]
My sound card back doesn't look exactly like those other ones (it's way older) but close enough. Thank you so much!! I'm quite excited now, you've made my day. Thanks for the help, the 3.5mm to optical is exactly what I need. --71.117.47.195 (talk) 16:42, 23 July 2009 (UTC)[reply]
Good! If you don't know which 3.5mm socket to choose - it's probably the "line out" socket. —Preceding unsigned comment added by 83.100.250.79 (talk) 16:51, 23 July 2009 (UTC)[reply]
I checked the back and I'm 99% positive that it is the "Digital out" jack. Thanks again! --71.117.47.195 (talk) 20:14, 23 July 2009 (UTC)[reply]

Restoring an iPod 3G Clickwheel

I have an iPod (clickwheel) whose internal database has gotten corrupted. It shows up as a USB drive, and I was able to (in Terminal) copy all the files off of it to my computer. The problem is, it doesn't show up in iTunes at all, so I can't "Restore" it.

Is there a way to Restore an iPod that iTunes doesn't recognizes? The iPod itself seems functional except that it doesn't remember that I have any music. The internal interface works fine, though.

I'm using a MacBook with OS X 10.4.11, with the latest version of iTunes (updated just a day or so ago), if that helps. Any suggestions? --98.217.14.211 (talk) 17:43, 22 July 2009 (UTC)[reply]

Apple has a note about how to reset a horked iPod here. -- Finlay McWalter Talk 17:52, 22 July 2009 (UTC)[reply]
Err, no. It was not a problem with it freezing. --98.217.14.211 (talk) 18:13, 22 July 2009 (UTC)[reply]
Ah ha! I figured it out. I used the old, now-unsupported iPod Updated 2006 which restored it even though it wouldn't work in iTunes. Hooray. Now it shows up in iTunes and will let me use it again. Yay for me. --98.217.14.211 (talk) 18:13, 22 July 2009 (UTC)[reply]

Caches, and proxies, and cgis, oh my

OK, looks like we have a group of venerable referencedeskers, who seem to be able to answer any question one throws at them. I wonder if you folks could help me?

Here is my problem. There is a closed online system that I need to access (yeah, I have access rights, no worries there). The system is basically run via a cgi script--a user is presented with a form in a browser, fills it out, hits submit, and gets the results. Unfortunately, the system's interface gets tweaked every now and then. What this means, is that on some days some parts of the interface are different from what they used to be on the day before (and these are not visible changes; just changes to how the system works beneath). In most cases, clearing browser's cache is all that needs to be done, but on some truly sad days that does not work. The reason it does not work is because some of the js, css, and htm files get cached on the proxy server (to which I do not have access). Instead of getting these parts from the system upon request, the smart-ass proxy decides to serve the files previously cached. Yeah, the files have the same names, but the content is slightly different, which means that on my end the parts don't assemble well, which leads to all kinds of nasty errors.

So, the question--in a situation like this, is there a way to tell the proxy to go funk itself never cache anything from that website? If it were just a regular html page, one could add "?whatever=anything" at the end of the URI; unfortunately, since this is a cgi call, adding random crap like this at the end of the URI means that the request won't be processed because of "unknown parameters".

The problem appears only on the PCs which are all hooked through the same proxy. When accessing the system from home, I never have this kind of problems (which, for one, says that my ISP's proxy server is configured much better than the one at work).

I searched the web for several days now, and the closest I could find was this, which isn't exactly helping. Can this even be done (please say yes)?--Anonymous and desperate in the Midwest

Pushing ctrl-f5 on firefox (shift-reload on IE, I think) makes the browser send magic stuff in the request headers of its HTTP request, which tells the intermediate proxy to ignore its cache and go ask the real source. The way it does that is by setting a "cache-control:no-cache" line to that header. So if you were writing a program to web scrape the system, you could add that line to your own program's http request header. If you're using a browser, then I don't know of a way to force a browser to always set that header (but I'd be surprised if there isn't a Firefox plugin to to just that). You could also run another http proxy of your own (which points at the real proxy) and hard-wire it to set cache-control; or you could skip the proxy altogether and tunnel http through ssh, and so talk to the real server. -- Finlay McWalter Talk 19:25, 22 July 2009 (UTC)[reply]
Firefox BetterCache plugin lets you control the browser's cache-control settings better; it seems to be targetted at the opposite of what you want (caching more stuff, not less) but it may also have a "don't cache site xyz.com" option too. -- Finlay McWalter Talk 19:29, 22 July 2009 (UTC)[reply]
Good advice, thank you. Wouldn't work, though. First, I should've specified that the system only works in IE (so FF plugins are out), as it relies heavily on ActiveX. And Ctrl-F5 does not do it magic, for whatever reason (neither does nuking the browser cache). As for setting up a local proxy, it would still have to go through the company proxy (that's company's policy), so I suspect the local proxy will still be fed the exact same outdated stuff coming from the company proxy. Might be worth a try, though. Any other suggestions, anyone?--Adim

Back button was no longer blue

The details of my computer are here.[4]

I was editing an extremely long article, one that has been tagged so it can be split.

I tried to go back to what I was doing before I did that and the back button was no longer blue. I've seen this happen outside of Wikipedia with extremely long emails (that's how I stored stuff before I had a computer, and I don't risk losing the stuff even now by using the computer).Vchimpanzee · talk · contributions · 20:26, 22 July 2009 (UTC)[reply]

Okay, if the button is not BLUE, it's dark gray and clicking on it produces no action.Vchimpanzee · talk · contributions · 20:04, 24 July 2009 (UTC)[reply]

No idea. It happens to me, too, every now and then, not often enough to have investigated why. It's the tab history dropping off. If you find it happening only on very long files, duplicate the tab first, to have a spare. - KoolerStill (talk) 07:58, 26 July 2009 (UTC)[reply]

unable to show hidden folders

my option to show hidden folders from the folder options isnt working. When i enable it it reverts back and hides the hidden folders. whats happening how do i enable it? —Preceding unsigned comment added by 193.220.225.251 (talk) 21:51, 22 July 2009 (UTC)[reply]

Do you get to see the hidden folders once? or does it never work? (Did you press "apply")83.100.250.79 (talk) 22:49, 22 July 2009 (UTC)[reply]
A google search http://www.google.co.uk/search?hl=en&q=show+hidden+folders+reverts&meta=&aq=f&oq= mentions a virus related issue, as well as issues (bug) with subfolders when the folder contains no files (or something) - do either of these two ring a bell.?83.100.250.79 (talk) 22:56, 22 July 2009 (UTC)[reply]

Jailbreak

what is jailbroken cell phone? —Preceding unsigned comment added by Cdn1 (talk • contribs) 21:55, 22 July 2009 (UTC)[reply]

see Jailbreak (iPhone OS). -- Finlay McWalter Talk 21:55, 22 July 2009 (UTC)[reply]

Linux (wasn't he from Charlie Brown?)

So my auld laptop is dying, so I reckon it may reincarnate a little if I stick Linux on it. Wubi is the only installer I've used to date, therefore giving me a way back; but due to this computer's limited HD space, I would prefer a full conversion. How should I go about this, and how can I save my documents (conveniently in opendocument format) and move them back after opensourcification? Fribbler (talk) 23:09, 22 July 2009 (UTC)[reply]

I use Ubuntu linux (which may or not be a recommendation); what I'd do is the following:
  • download the latest ubuntu installer, and burn it to a CD
  • boot the auld laptop wi the ubuntu CD, find your files, and copy them to a USB stick. Make sure to get everything you need, as the next phase is destructive.
  • once you're sure, have the ubuntu installer wipe the disk and install a fresh linux partition on it (linux will offer to be nice, to do things like dual boot and stuff, but if you're hard-disk constrained then that's not such a good idea).
This should be enough. If your laptop is guy auld then full Ubuntu might be a bit heavy for it, so Xbuntu or even Puppy Linux would be a better fit. Once you've installed, plug the usb disk in again, and copy the saved files to your "Documents" folder. -- Finlay McWalter Talk 23:44, 22 July 2009 (UTC)[reply]
Thanks Finlay. The laptop should survive full-linux-install. It's still got a 120GB HD (but would struggle with dual-boot), but those are the instructions I needed, thanks! Fribbler (talk) 23:49, 22 July 2009 (UTC)[reply]
Of course, you could try out various linuxes on Live CDs first. It'll save a lot of hassle installing one, then finding you don't like it and having to install another, and so on. Astronaut (talk) 20:02, 23 July 2009 (UTC)[reply]
I had done that part, and setlled on Ubuntu a while ago. Now I'm writing this on a Linux-only system! Much faster. Fribbler (talk) 21:12, 23 July 2009 (UTC)[reply]
When choosing Linux, many will get into a debate about Ubuntu vs. Fedora (or something similar). These are distributions that differ mainly in how you install/update all the programs. The linux will be the 2.6 kernel regardless of your choice. What actually affects your usage is the desktop environment. There are two main choices: GNOME and KDE. Both Ubuntu and Fedora (and all other distributions that I've used) have GNOME or KDE options. I suggest using a live CD (Ubuntu is GNOME and Kubuntu is KDE .. or get Fedora Live for GNOME and Fedora KDE Live for KDE). You can mess around with the two desktops and decide which one you like. Once you get hooked on one, switching to another is like switching from Windows to Linux. I've been using KDE for about 10 years. When I use GNOME I spend most of my time trying to figure out where they hid the button or menu item that I need. -- kainaw™ 21:18, 23 July 2009 (UTC)[reply]


July 23

How to create a PDF file for free?

I placed this at the Wikipedia:Help desk and Steve was so nice to refer me to this board which I wasn't aware of:

I need to scan in and send some papers in PDF format (ASAP), but I don't want to buy the quite expensive software since I never needed it before and I'm sure I won't need it again in the near future. I wrongly thought [wishful thinking] Adope Photoshop (which I have) would work to convert my files. Is there a simple way out of this? Any help would be much appreciated. Thanks,--The Magnificent Clean-keeper (talk) 00:06, 23 July 2009 (UTC)[reply]

PS:"I already checked our articles about PDF's but couldn't find anything helpful for my case.The Magnificent Clean-keeper (talk) 00:06, 23 July 2009 (UTC)[reply]

I believe Open Office has the option to save as PDF. There may be something more lightweight...or appropriate for scanned materialsFribbler (talk) 00:11, 23 July 2009 (UTC)[reply]
I would like to be (at least pretty) sure before I download some major program as there are several which might or might not do what I need. But thanks for you trying to help me. Best, --The Magnificent Clean-keeper (talk) 00:37, 23 July 2009 (UTC)[reply]
http://sourceforge.net/projects/pdfcreator/ is a good piece of software. Install it and you can print to a PDF. So you can scan to an image file, then print the image file to PDF. - Akamad (talk) 00:26, 23 July 2009 (UTC)[reply]
My mistake. I wasn't clear in my initial question. I need to send these papers per e-mail so printing is not my problem. :( --The Magnificent Clean-keeper (talk) 00:37, 23 July 2009 (UTC)[reply]
The software that Akamad linked is a fake printer. It shows up in the Windows printer list, but when you "print" to it, instead of producing a physical piece of paper, it produces a PDF file. APL (talk) 00:46, 23 July 2009 (UTC)[reply]
I just tried it. It works great. I now have a PDF of today's Computing reference desk. Easy. Thank you User:Akamad, this is a handy program. APL (talk) 00:49, 23 July 2009 (UTC)[reply]
What type of computer are you using? That will help us a bit in recommending the software (there are many choices). Also, when Akamad says "print the image file to PDF," what he means is that most PDF creators (other than Adobe Acrobat) are printer drivers: you "print" to the PDF software, and it grabs the "printed" data (which would normally be sent to your printer), and turns that into a PDF.
Incidentally, if you have a scanner, check that it doesn't already have a "document" mode for scanning. Most do, these days, and they will automatically turn documents into PDFs. --98.217.14.211 (talk) 00:42, 23 July 2009 (UTC)[reply]
I'm running a PC with XP and since my good scanner has problems I'm stuck with like a "first generation" scanner. Can't expect much out of it.--The Magnificent Clean-keeper (talk) 00:52, 23 July 2009 (UTC)[reply]
Maybe not, but you might check if the company has updated scanner software that is compatible with it. Making it into a PDF is a software-side thing, so that can be updated, even with an old scanner, much of the time. --98.217.14.211 (talk) 02:41, 23 July 2009 (UTC)[reply]
    • Update: Unfortunately I'm back and unfortunately I don't think there is a way out. I could scan and save my files as PDF with Adobe Photoshop (even so it didn't work before; Don't know why). Now the only probably unsolvable problem [w/o Adobe reader pro] is to make a single file out of them. This has some importance in my case. Does someone has an idea how to do this without the Adobe software? I tried several things inclusive promising free programs but nothing works. Also Openoffice doesn't do the job as someone recommended to give it a try (yet I'll keep it on my PC as it seems to be a quite good program. Anyways, if I don't find a solution I'll have to send the PDF's as single files [one file per page]which hopefully will be accepted from the receiving party.
Appreciated for some new possitive input as far as it is possible, --The Magnificent Clean-keeper (talk) 21:49, 23 July 2009 (UTC)[reply]
This google search seems to point to freeware which combines multiple PDFs into a single PDF. However I can vouch for none of it.—Preceding unsigned comment added by Tagishsimon (talk • contribs) 22:04, 23 July, 2009 (UTC)
Gosh. I was so fixated on Wiki that I've not even thought about doing a google search. Shame on me! I'll check out what google has to offer and hope I won't need to bother again. Thank you Tagishsimon.--The Magnificent Clean-keeper (talk) 22:28, 23 July 2009 (UTC)[reply]

LaTex and “smart quotes”

In LaTex, it appears that the default output for the command " is ”, the closing "smart quote" - whether or not the quote is an opening quote or closing quote. Is there a command to make it output “ instead? --72.197.202.36 (talk) 03:07, 23 July 2009 (UTC)[reply]

I use two backquotes (``) for the opening quote, and two single quotes (apostrophes) ('') for the closing quote. --Spoon! (talk) 06:31, 23 July 2009 (UTC)[reply]
And that's in fact the LaTeX-approved way to do it. Best not to have any " characters at all in your input file. rspεεr (talk) 06:42, 23 July 2009 (UTC)[reply]

Hypercam

HyperCam used to be able to record sound for me, but now, it can't. Why? How can I fix this? 121.220.109.214 (talk) 09:40, 23 July 2009 (UTC)[reply]

Running a server from within Virtualbox

So I've set up windows xp in virtualbox and got a simple webserver running on it. All works good from the VMs localhost, but how do I direct outside connections to the server running in virtualbox?

You're looking for port forwarding. Since you're using Windows, you'll probably need to set it up through VirtualBox, since afaik Windows doesn't offer any tools for port forwarding. Here's two guides to setting up VirtualBox to forward ports. 1 2 You'll also need to make sure that your firewall has those ports open. Also keep in mind that if your windows xp computer is behind a home router, it's probably already using NAT and the virtualbox server will be double-NATed, which often causes problems. Plus you'll need to forward the port from your router to your windows xp computer, then from there to the virtual server. Indeterminate (talk) 21:47, 23 July 2009 (UTC)[reply]

Books

On social networking sites, why do many people claim they hate books? 121.220.109.214 (talk) 10:44, 23 July 2009 (UTC)[reply]

Whatever reason it is, I think it has more to do with the people themselves than the fact they are on social networking sites, ie they'd say they hate books irl too —Preceding unsigned comment added by 82.43.91.128 (talk) 11:03, 23 July 2009 (UTC)[reply]
Perhaps because they like things that only require a brief attention span - hence the success of Twitter which I think is limited to 40 characters - and do not like the much longer attention span required to read a book? 78.147.241.234 (talk) 11:23, 23 July 2009 (UTC)[reply]
My theory is that it's because a tremendous number of people are poor readers. I would hate books too if I couldn't read them fast enough to hold my interest. (Might cause a bit of sour grapes too. )
I'm sure there's some antiintellectualism mixed in there too.
And, as with all things "Social", some people say it because the cool people are saying it. APL (talk) 12:47, 23 July 2009 (UTC)[reply]
(I assume they mean novels and not cookbooks and the like.) APL (talk) 12:51, 23 July 2009 (UTC)[reply]

Auto script

Is it possible to write a script that would automatically make a post on the internet, for example a blog or open forum? How would I write such a script? What language? Would .bat do? This is on a windows computer btw and I have zero previous programming knowledge —Preceding unsigned comment added by 82.43.91.128 (talk) 11:08, 23 July 2009 (UTC)[reply]

Lots of blogging (and the like) systems have Application Programming Interfaces which allow entries to be made programatically - Twitter and Blogger, for example. Windows batch files are not appropriate for this; a proper programming language like Python, Perl, Java, or C# is necessary. Posting to a forum that doesn't have an API is possible, but would require a more sophisticated screen scraping system. All of this will require some modicum of programming. -- Finlay McWalter Talk 11:43, 23 July 2009 (UTC)[reply]
Oh, and forums that want to discourage spammers using automated scripts often employ a CAPTCHA; getting around that is very difficult. Unfortunately such countermeasures also thwart legitimate uses as well as spam. -- Finlay McWalter Talk 11:45, 23 July 2009 (UTC)[reply]
Thanks for the reply :) I've used iMacros a few times but it's very buggy, but I guess I'll have to stick with it unless I want to learn programming languages! Thanks anyway —Preceding unsigned comment added by 82.43.91.128 (talk) 11:47, 23 July 2009 (UTC)[reply]
Learn python; it's dead easy, and you'll never again be the prisoner of a bunch of weird buggy programs that won't work together. -- Finlay McWalter Talk 12:28, 23 July 2009 (UTC)[reply]

Best quality way to edit Flashvideo .flv files, for free?

There seem to be two routes: 1) directly editing with a .flv editor, although the only free one I'm aware of so far is VideoThang, or 2) translate the .flv format into another format and edit that. Does anyone know what the best route would be to preserve the best picture quality, using what software? Edit: another FLV editor I've found is Avidemux (Have edited Flash Video article accordingly). Are there any more please? 78.147.241.234 (talk) 11:21, 23 July 2009 (UTC)[reply]

Well, when you convert FLV to another format, you almost always lose picture quality by definition (see transcoding). That's not good with FLVs, where the quality is usually low to begin with (low resolution and high compression). So anything you can do that involves not transcoding (editing it with something that understands FLV natively) is a good idea. --98.217.14.211 (talk) 12:50, 23 July 2009 (UTC)[reply]
Flash video isn't an encoding format, it's a container format. So it's perfectly simple to transfer it to another container format without any transcoding or any loss of quality (it's the same stuff in a different wrapper). I use mencoder: mencoder -oac copy -ovc copy -o outputfile.avi inputfile.flv . This should open up more video editing programs (ones that understand .avi or .mpg wrappers, but not .flv); you might still run into a codec incompatibility (as FLVs can be encoded with a variety of codecs), however. -- Finlay McWalter Talk 13:06, 23 July 2009 (UTC)[reply]

Thanks. Are YouTube videos encoded in this way? I'm rather surprised that FLV is simply wrapped-up AVI - really? Are there any converters with a less intimidating GUI please? 89.240.217.9 (talk) 19:39, 23 July 2009 (UTC)[reply]

Mediacoder is free, works great, and has a GUI, although it can be a bit intimidating. Videora has a friendlier GUI, but it only converts into MPEG-4 H.264 (used by iPods, but also a common video standard). There are probably many others. Indeterminate (talk) 21:37, 23 July 2009 (UTC)[reply]

Windows 7 IE Europe How?

According to Windows_7#E_editions there won't be internet explorer on some version - so how does one get any browser at all?83.100.250.79 (talk) 13:20, 23 July 2009 (UTC)[reply]

One downloads the browser one likes the most. Internet Explorer, Mozilla Firefox, Opera, Sarari, and Google Chrome can be downloaded by anyone in just a few minutes, completely free of charge. --Andreas Rejbrand (talk) 13:28, 23 July 2009 (UTC)[reply]
Well, one downloads those other browsers using a browser (downloading Firefox is the only thing I ever seem to use IE for). How to get IE, or any other browser, onto an IE-free machine will pose something of a delicate challenge for them. They'd probably have an "add optional components" program, which would fetch the IE interface over the internet. But if they just offer IE, then they may be in the same problematic anti-trust position as they are trying to avoid. Technically the fix is simple: an app that lets you pick from one of several browsers (IE, FF, Opera, Safari) and install the one(s) you want, but I can hear Balmer's teeth grind over that from here. -- Finlay McWalter Talk 13:39, 23 July 2009 (UTC)[reply]
There is a simple FTP client in Windows: just run "ftp". Probably there are many FTP servers that offer web browsers. But it is not nearly as convenient as going to e.g. firefox.com and download it. --Andreas Rejbrand (talk) 21:02, 23 July 2009 (UTC)[reply]
"going to e.g. firefox.com" with what? -- 87.114.144.52 (talk) 00:15, 24 July 2009 (UTC)[reply]
I think that was a comment.83.100.250.79 (talk) 09:48, 24 July 2009 (UTC)[reply]
Alternatively, those E-editions may only be offered to OEMs - so Dell or whoever would be able to ship with Firefox preinstalled but not IE (clearly Trident will still be installed regardless). The technicalities of all this are simple, but what the EU and MS are willing to put up with from the other is the hard part; it's in MS's interest to offer an IE-free version (as they offer a WMP-free version), but have in practice OEMs and users pick the with-IE version. Right now this is as much as we know - I don't believe MS have formally announced the actualities about how the IE-free E-versions will actually work. -- Finlay McWalter Talk 13:57, 23 July 2009 (UTC)[reply]
There could be a specialty FTP client included with an icon on the desktop whose only task, when launched, would be to go and fetch Internet Explorer, and place its installer icon on the desktop. Or the user could be told the arcane set of steps needed to run cmd and then go and FTP it. Unlikely, the latter, these days. Tempshill (talk) 15:49, 23 July 2009 (UTC)[reply]
Officially you need to download whatever browser you want in advance BEFORE you do the installation and save it to USB/CD etc and then install that after Windows 7 has been installed (or use another computer to download the installer and transfer it the Windows 7 machine). Of course unofficially you'll be likely be able to get whatever browser you want via scripting or FTP etc, but there's no "menu" or installer provided with Windows 7 to do so. ZX81 talk 16:15, 23 July 2009 (UTC)[reply]
Well done, you found it. So no special dialog box then..

Incidentally does anyone know if the 'browser' that can be obtained via windows help is IE independent - does anyone know what I'm talking about.83.100.250.79 (talk) 16:49, 23 July 2009 (UTC)[reply]

It's Trident (layout engine), which is the real core of IE. I rather suspect that when they say "we're not shipping IE" they mean "we're shipping Trident, just not the IE application that makes it a general purpose browser". If they didn't ship Trident, then all kinds of things (windows update, steam, windows help, and encarta) wouldn't work. 87.114.144.52 (talk) 18:08, 23 July 2009 (UTC)[reply]
The parts that do the networking are something else as well (I guess) eg whatever ftp.exe uses. Do those components have a name? Is it part of winsock? (networking leaves me totally blank)83.100.250.79 (talk) 09:50, 24 July 2009 (UTC)[reply]
Yes, I've seen this before, you can also uninstall IE in Windows 7 non-E. AFAIK, they basically do the same thing which is mostly remove the IE exe. There's also some info on compatibility problems in one of the MS blogs (of course they've looked at it). There aren't many except for stuff like brain dead apps which are hardcoded to use IE. And obviously if you don't have any browser and the software you use can't handle that. Nil Einne (talk) 22:39, 27 July 2009 (UTC)[reply]

Hot off the presses- Users get the choice at first boot after install 161.222.160.8 (talk) 19:58, 24 July 2009 (UTC)[reply]

DHCP problem

Hi,

i have configured the DHCP in VMware, its assiging the IP but not assiging the defualt gateway but i have setted the gateway also..what could be the reaseon or any setting problem. —Preceding unsigned comment added by Anand.khani (talk • contribs) 13:29, 23 July 2009 (UTC)[reply]

Is DNS getting set? -- kainaw™ 14:15, 23 July 2009 (UTC)[reply]

Firefox equivalent of Safari's .webarchive?

I've been using Safari since it was released. One feature I like is the ability to save webpages to self-contained .webarchive files. I've been using Firefox 3.6 more and more. But when I go to save a webpage I can either save it as a bare HTML file, which strips off all the graphics. Or a "complete" webpage that saves the HTML page plus a folder of graphics -- which is kind of a hassle to deal with. Is there a way for Firefox to save a complete page in one file (and not use PDF)? —Preceding unsigned comment added by 70.167.58.6 (talk) 14:23, 23 July 2009 (UTC)[reply]

Unofficially yes, but it's not especially practical. You save the files off as normal, zip them up, rename the zip file to being a .JAR, and then use the JAR url scheme to access the files within it. I've got a note written about how to do that last bit, I'll look it out for you. -- Finlay McWalter Talk 14:45, 23 July 2009 (UTC)[reply]
Here's the syntax - if the JAR is at /home/fin/foo.jar you'd tell Firefox to go to the following url jar:file:///home/fin/foo.jar!/index.html -- Finlay McWalter Talk 14:48, 23 July 2009 (UTC)[reply]
You shouldn't need to rename it to .jar, it should work fine with a .zip extension. Under Windows the syntax is jar:file:///c:/path/foo.zip!/index.html. -- BenRG (talk) 16:52, 23 July 2009 (UTC)[reply]
There are plugins that let you mirror sites with Firefox and probably ones that let you save them into single files. I've used a plugin called Scrapbook to save "whole" webpages (it downloads all the little images and etc., though it buries them into your Firefox profile directory) --98.217.14.211 (talk) 15:05, 23 July 2009 (UTC)[reply]

This is what you're looking for 8I.24.07.715 (talk) 15:15, 23 July 2009 (UTC)[reply]

I T knowledge.

I have very less knowledge on os,recent developments in hardware, softwares,..in general stuff related to IT and computers.Which is the best website that gives me all the updates??pl help —Preceding unsigned comment added by 117.193.139.41 (talk) 16:09, 23 July 2009 (UTC)[reply]

I recommend you start reading an IT news site every day (pick a sensible one not slashdot, or the register, or the inquirer).
I can only think of Ars Technica which covers both PC, entertainment electronics, and business IT. Hopefully someone else can suggest others.
As you come accross terms and concepts you don't understand, look them up (maybe on wikipedia)
I wouldn't expect to be able to follow everything, so it might be a good idea to concentrate on building up your knowledge in a selection of areas at first, and relying on other people for other topics.83.100.250.79 (talk) 16:42, 23 July 2009 (UTC)[reply]
You probably already know this, but I always thought the most valuable IT education was by doing it yourself; download Debian and use it to set up an e-mail server, a web server, a Mediawiki server; do the same with another couple of popular Linux distros; do the same with a version of Windows Server, etc. Tempshill (talk) 17:32, 23 July 2009 (UTC)[reply]

Wii OS

What programming language would you suppose the Wii's operating system is written in? -- penubag  (talk) 18:39, 23 July 2009 (UTC)[reply]

The official devtree for Wii is Freescale's Codewarrior C++ tree (ref); there's no reason to suppose that system (wii-IOS) development would be done with a substantively different toolchain. So "C or C++" is the answer, although when C++ is used for systems programming the system programmers often dictate a lengthy list of thou-shalt-nots which preclude a bunch of standard C++ features (rtti, pure-virtual, templates, exceptions) that reduce C++ to being a C-with-classes subset some call C++-- 87.114.144.52 (talk) 19:13, 23 July 2009 (UTC)[reply]
In addition a tiny amount of assembly is usually required, but these days that's usually limited to a few instructions on startup (setup the CPU and a stack for C to run in), wrappers around interrupt handling (push and pull registers, maybe weird stuff like branch-delay slot recalc) and a very few pieces of hand-optimised sections like filter kernels, the data pump of media codecs, and texture scalers. 87.114.144.52 (talk) 19:19, 23 July 2009 (UTC)[reply]
Thanks very much for the thorough answer. I appreciate it. -- penubag  (talk) 22:42, 23 July 2009 (UTC)[reply]

Minus everything else, how long do you suppose it took to make the OS? -- penubag  (talk) 08:12, 24 July 2009 (UTC)[reply]

What are the most active discussion forums on the web?

What are the most active discussion forums on the web? --Gary123 (talk) 18:58, 23 July 2009 (UTC)[reply]

Here's a site that tracks members and posts. [[5]] 24.6.46.177 (talk) 19:50, 23 July 2009 (UTC)[reply]

Quality control with AdSense Competitive Ad Filter

On my new blog, I'd like to perform some quality control on the AdSense ads. I'm particularly concerned with eliminating the following:

  • Health care products and advice that is contrary to medical consensus or sold without a license.
  • Malware.
  • Products and services based on pseudoscience or claims of the paranormal.
  • Religions and cults.
  • Conspiracy theories.
  • Political conservatism.
  • Get-rich-quick schemes.
  • Unaccredited colleges.
  • Tools for speculating on commodities and foreign currencies.

Are there any sites that can provide black lists or other tools to help do this with AdSense's Competitive Ad Filter? NeonMerlin 22:18, 23 July 2009 (UTC)[reply]

Disable Firefox 3.5's top bar slide effect?

Whenever Firefox 3.5 blocks a popup or asks you to save a password, the top bar slides down, moving the page with it.Same thing happens when you close a page. is there anyway to disable it? 24.6.46.177 (talk) 22:49, 23 July 2009 (UTC)[reply]

You might find the option to disable it entirely in about:config but I'm not sure. Until someone who knows better can say, I might have an indirect solution. If you add Adblock Plus you will no longer get popups from advertisers (if that's what's causing the problem) and if you navigate to Tools>options>security>passwords>... you can tweak some settings so it doesn't ask you. Again, I know this doesn't answer your question but maybe someone else knows the answer. -- penubag  (talk) 06:43, 24 July 2009 (UTC)[reply]
I recommend AdBlock Plus regardless. It's great.
There are two settings in the about:config screen. (Put about:config in the URL bar and hit enter.) Search for "alerts". There's two variables having to do with "SlideInterval". I haven't figured out how these work, but I'll bet some experimentation could stop it from sliding. APL (talk) 13:10, 24 July 2009 (UTC)[reply]
It's not in about:config sadly. There might be a userchrome.css tweak for it but I haven't found one. The alerts configs refer to the alert boxes in the lower right of the screen, like the download alert. I already have adblock plus, and I would rather have the annoyance of the sliding than disabling it altogether. 24.6.46.177 (talk) 16:08, 24 July 2009 (UTC)[reply]
You should probably ask your question here: http://forums.mozillazine.org/viewforum.php?f=38 I'm sure they know more than us. -- penubag  (talk) 22:10, 24 July 2009 (UTC)[reply]
Already did, but I'll just live with it since a) it doesn't come up too often b) I'd rather see it and be annoyed than not see it at all. —Preceding unsigned comment added by 24.6.46.177 (talk) 02:25, 25 July 2009 (UTC)[reply]
You can totally disable the notification bar for popups with privacy.popups.showBrowserMessage, but you'll still get it for "remember this password?" dialogs.Indeterminate (talk) 00:20, 25 July 2009 (UTC)[reply]

Painting in Java

Hello! I haven't done very much with the java.awt package or anything with graphics other than Swing, and I have a question. I'm trying to paint (i.e. fill()) an Ellipse2D on a JLabel in a JLayeredPane (the JLabel is on the top Layer above everything else, so it's not covered up). These are the snippets of code that I have that I've used for this purpose: 

Graphics2D g2 = (Graphics2D) myJLabel.getGraphics();
g2.setPaint(Color.WHITE);
Ellipse2D.Float point = new Ellipse2D.Float(200, 200, 100, 100);
g2.fill(point);

The fill() method is part of an actionListener, and when I run my program and trigger the action, I see a white ellipse for a very, very brief moment, and then it goes away (i.e. I see the layer below). I want the ellipse to remain there. What am I doing wrong? I have a felling it has something to do with the concurrency of Swing. (I'm running NetBeans, if that makes any difference.) Any help much appreciated. Thank you!--el Aprel (facta-facienda) 22:48, 23 July 2009 (UTC)[reply]

In general it's better to paint on a canvas or jcanvas rather than a specific widget like a Label or JLabel, as you're not fighting with the control's own draw code; so if you want to change the appearance of a JLabel, the safest idea is to subclass the look and feel and do it there. But it is generally safe to do, if you implement both the paint() and update() methods of your own subclass of JLabel and do all the painting there. You're doing something else - you're getting the graphics context from another place, and painting on it - that works, but your work gets undone as soon as something makes the JLabel draw itself. So instead add your paint code to a subclass of JLabel, implement paint() and update(), and in your other code just throw a damage at the widget by calling its repaint() method. Repaint just adds a "repaint me" event to that component's queue, so this makes sure that all the repainting happens in the appropriate eventqueue thread, and so swing takes care of the threading problem for you. 87.114.144.52 (talk) 23:11, 23 July 2009 (UTC)[reply]
Actually when I say "that works", I'm wrong. That works for java.awt (which relies on the native code for thread safety), but not for swing (which explicitly and deliberately isn't threadsafe). 87.114.144.52 (talk) 23:13, 23 July 2009 (UTC)[reply]
Repaint() has another nice feature (in addition to not breaking everything); swing implements damage event ellision, so if multiple repaint events are adjacent in the queue (some thrown by you, some by the window manager, some by other bits of the system like the LnF) it will join them together into one big fat repaint event. If there are lots of paints going on, this makes for a significant performance enhancement. 87.114.144.52 (talk) 23:16, 23 July 2009 (UTC)[reply]
Bah, I'm wrong again. Override paintComponent(), not paint() 87.114.144.52 (talk) 23:26, 23 July 2009 (UTC)[reply]


July 24

Wireless G & N

Hi, I'm trying to advise my folks on wireless routers despite being fairly ignorant myself. They have DSL, not sure which plan, but definitely not FiOS. My understanding now is that their download speeds are well below the maximum throughput of Wireless-G of 54 Mbit/s, much less N, so they don't need to buy a more expensive Wireless-N router. Is there any strong reason to recommend the N-types? Thanks. —Preceding unsigned comment added by 141.154.119.192 (talk) 03:19, 24 July 2009 (UTC)[reply]

N has a greater range as well as speed. Though that may not make a difference to you! Mxvxnyxvxn (talk) 04:43, 24 July 2009 (UTC)[reply]
Ok thanks, might make a difference to my folks. 141.154.119.192 (talk) 11:54, 24 July 2009 (UTC)[reply]

How do I remove colored backgrounds when viewing websites? On Firefox

How do I remove colored backgrounds when viewing websites? Dark background make the text hard to read. --Gary123 (talk) 04:12, 24 July 2009 (UTC)[reply]

I usually just select the text I'm trying to read (either with the mouse or Ctrl-A to select all). Another option is to go to Tools, Options, Content, Colors, uncheck "Allow pages to use their own colors". But that'll apply to all pages. You can also try View, Page Style, No Style. But for most sites, it'll break the design. You could also try looking for add-ons that let you change background colors easily. Indeterminate (talk) 05:03, 24 July 2009 (UTC)[reply]
If you use the web developer toolbar in Firefox, in its images menu there is a "hide background images" checkbox, which hides background images set both in html and by css, while leaving the rest of the page's layout and style alone. 87.114.144.52 (talk) 12:21, 24 July 2009 (UTC)[reply]

MS Vista's compatibility

When I run old outdated software, Vista says that the software has known compatibility problems. How does it know that? I know it doesn't check the web because I'm not at a hotspot, but does it have an on-board list of incompatible software? I would guess not. Theories I've come up with so far are that it looks at the date of the software and just assumes that it will have compatibility problems and by looking at the way the program is written. The latter seems like it might take some time to analyze but the notice appears instantly. What's your take? -- penubag  (talk) 06:35, 24 July 2009 (UTC)[reply]

Hopefully someone who knows about this specific error message will answer you but here's what I know :
What I learned from the book "The Old New Thing" (Written by an MS employee on the Windows back compatibility team) is that Windows does keep a built-in list of incompatible software. In fact, sometimes there is a built-in solution to the problem. APL (talk) 13:07, 24 July 2009 (UTC)[reply]
That's interesting but I still find it unlikely. I was running an outdated version of Adobe Acrobat and that message came up. Does that mean it even has a list of 3rd party programs? I wonder if this list can be salvaged be looking at the innards of Vista. -- penubag  (talk) 22:13, 24 July 2009 (UTC)[reply]
Yes, they definitely have that list (I believe it's a hashtable correlating binaries' checksums with a compatibility setting). The blog of Raymond Chen, the author of the book APL, describes the sometimes Byzantine lengths to which MS goes to get specific badly-written programs to run on later versions of Windows. Sure, you could reverse engineer this info out of Windows, but the subtext of Raymond's blog is generally "rely on undocumented stuff now, repent at leisure". -- Finlay McWalter Talk 22:35, 24 July 2009 (UTC)[reply]
Wow that's interesting, thanks -- penubag  (talk) 23:31, 24 July 2009 (UTC)[reply]
It's probably also a good indicator of compatibility issues if a program calls a deprecated system call or library function. Indeterminate (talk) 00:17, 25 July 2009 (UTC)[reply]
Yes, the compiled binary program will indicate which versions of the Windows and MFC APIs it intends to use. If the current version of Windows cannot provide that API (or must provide a different version), the operating system can warn the user. "Possible compatibility issue" is more user friendly than "COM+ library version 2.3.1 requested, substituting 2.3.3" (or whatever). Unfortunately, the user-friendly message makes it difficult for even a technically proficient user to diagnose exactly what compatibility is needed to find a fix. Nimur (talk) 15:41, 25 July 2009 (UTC)[reply]

Mathematical equations in a document

The story so far: I have to display mathematical stuff such as matrices , logarithms etc in a word document. Initially I made them in mspaint and inserted these images in word. It is too time consuming and changes cannot be made easily so I googled for a tool for working with matrices and found http://math.exeter.edu/rparris/winmat.html. This tool has an option of creating .tex document, which I found out to be latex format. The trouble is iam not able to view the matrices with this tool http://www.exomatik.net/LaTeX/USBTeXEnglish#toc3 . --- Nothing has worked yet as I have not found a way to easily create mathematical formulas and equations that can be displayed in a word document. Please say how it is done with free tools. —Preceding unsigned comment added by 131.220.46.25 (talk) 11:51, 24 July 2009 (UTC)[reply]

All versions of Microsoft Word (at least since Word 97) have included a very easy-to-use formula editor named "Microsoft Equation", commonly "Microsoft Equation 3.0". To use this, choose Insert/Object/"Microsoft Equation". Then you get professional-looking (far superior to MS Paint drawing!) formulas, that can be edited at any time. In addition, the new Microsoft Office Word 2007 has a much improved formula editor, now as integrated into Word as options such as "bold", "italic" etc. --Andreas Rejbrand (talk) 13:01, 24 July 2009 (UTC)[reply]
In Word 2007 just go to Insert > equation on the ribbon (click the "pi" symbol rather than the word or arrow underneath or you get a rather unhelpful list of "standard" equations). I've checked and matrices and logarithms are both covered. If you prefer OpenOffice this can also handle mathematical equations using insert > object > formula. See here for more info. 194.164.140.216 (talk) 13:08, 24 July 2009 (UTC)[reply]
You might need to "activate" Microsoft Equation Editor on some computers, (it may not be installed as standard) - ask if this is the case.
If you haven't got it (ie if you're using XP home + one of the lesser or older versions of word you could look at Category:Formula editors which gives a short list of programs, the majority of which are free.
To display in a MS Word document, you could either - export as a image (eg .bmp , .jpg , .png) which is easy. Or export as an 'object' - I think MS Word accepts OLE objects, which is probably what you need. Why not try one that looks ok and see how you get on (they're mostly small downloads). Or wait for more advice..83.100.250.79 (talk) 13:14, 24 July 2009 (UTC)[reply]
And supposedly faster and smoother than using Equation Editor is the Rapid Pi add-on. - KoolerStill (talk) 14:05, 24 July 2009 (UTC)[reply]
Click to expand
I've just been trying a few out, and I found Formulator MathML Weaver to work, and be relatively easy to use (ie instructions probably not needed), (everything seems to be selected through drop down boxes), I got a nice matrix image and integral made in minutes (with no prior experience), and it exports as .BMP which you can use anywhere.(See image converted to .jpg of example made up formula)
It's free too. In the absense of other solutions I'd try this, - if you do, ask if you get stuck..83.100.250.79 (talk) 14:17, 24 July 2009 (UTC)[reply]

Running a perl script on a web server

Resolved

Hi I'm trying to set up this perl script but I keep running into the following error "500 Internal Server Error, The server encountered an internal error or misconfiguration and was unable to complete your request." From the apache error log here's the following:

Anyone able to tell me what I need to do? Thanks :)

The last 2 lines are the problem; it's trying to run a script called C:/TWAMP/htdocs/wakaba/wakaba.pl and it says it can't find that file. So you either need to supply that file in that location or remove mention of it from the apache config files. 87.114.144.52 (talk) 13:30, 24 July 2009 (UTC)[reply]
If that files does exist, at that location, then the server (which runs as another user) can't open the file, so make sure the file permissions allow the web server to access the file. 87.114.144.52 (talk) 13:31, 24 July 2009 (UTC)[reply]
"500 internal server error" unfortunately can mean a million little things, ranging from missing files, bad permissions, or even wrong encoding. Try fiddling with all of these things. --98.217.14.211 (talk) 13:32, 24 July 2009 (UTC)[reply]
Thanks. The problem is that C:/TWAMP/htdocs/wakaba/wakaba.pl is right there, and is in fact the file I'm entering in the address bar of my browser with localhost/wakaba/wakaba.pl
I'm really at a loss what to do. The server runs php scrips just fine in exactly the same directory. I've installed ActivePerl and everything


No worries everyone, I found out what the problem was I had the incorrect hash bang in the .pl file. Thanks everyone!

How to find out duplicate lines?

There is a plain text file and contains thousands of lines in it. It looks like: 

frkookoww
fdewkoofow
koroorg
fwkoofw
gktoot
gogoldds
fdewkoofow
koroorg
kofroroooooa
.
.
.

Some lines are the same. I want to find duplicate lines out and delete them. Do you know any softwares for this job? By the way, supporting Unicode is better. --百楽兎 (talk) 13:36, 24 July 2009 (UTC)[reply]

I'd use sort and uniq. Assume my file is called "lines.txt", I would run: "sort lines.txt | uniq > newlines.txt". If you don't have Linux/Unix, you can get Windows versions of sort and uniq. -- kainaw™ 13:39, 24 July 2009 (UTC)[reply]
If it's not acceptable to re-order the file, the following Perl command will do the job:
perl -ne 'print unless $seen{$_}++' lines.txt > newlines.txt
--Sean 14:06, 24 July 2009 (UTC)[reply]
Thank you. I think sort and uniq for windows seems easier to me. But I just want to uniq it without sorting, what should I do? --百楽兎 (talk) 15:14, 24 July 2009 (UTC)[reply]
The uniq function requires a sorted list. It simply will not work on an unsorted list. If you want to get real technical, uniq requires duplicate lines to be grouped together - and sort groups them. The other option is to write a script (like the perl script above). Some are one-liners (like perl) and some will be multiple lines. If you are looking for efficiency, this is a semi-common computer science homework problem. It has a recursive solution. Cut the file in half. Remove duplicates in each half. Compare both halves to see of they have any lines in common and remove them from one half or the other. The first step (remove duplicates in each half) is the recursion. You cut that half in half and remove duplicates in each half... On a single computer it isn't very efficient. If you are running on a parallel system, you can farm out the work to many other computers. -- kainaw™ 15:33, 24 July 2009 (UTC)[reply]
You could load the file in your browser, paste the following:
javascript:c=s=""; h={}; a=document.firstChild.innerHTML.split(/\n/g); for (v in a) if (!h[a[v]]){h[a[v]]=true; s += a[v] + "\n"}; s
into the location bar, and then save the file as text. It worked for me in Firefox, but your mileage will certainly vary. --Sean 16:32, 24 July 2009 (UTC)[reply]
It's not as nifty as the other options given above, but you could also do this in Excel fairly easily. Copy and paste the list into Sheet1 and again into Sheet2. Assuming your lists start in cell A1, type the following in cell B1 of Sheet1: =countif(Sheet2!a:a,a1) and then double click the box in the bottom right corner of the cell to auto-fill in the formula - the results will be the number of iterations of each term in the list. In column C, put a 1 in cell C1 and a 2 in cell C2 and use the same double-click trick to auto-fill column C with numbers (to preserve the original order). Sort by column B to find and delete the duplicates, then sort by column C to restore the original order. Matt Deres (talk) 19:48, 24 July 2009 (UTC)[reply]
Thanks all friends! I learned very much from your wise solutions. All are cool. --百楽兎 (talk) 23:44, 24 July 2009 (UTC)[reply]

A PROGRAM NEEDED

hello, give me a good C program to print the following pattern using both (i) arrays and structures (ii) array pointers and structure pointers note: the * symbol must be printed using a function and not directly using printf statement PATTERN: 

*************************************************** 
         ANNA UNIVERSITY, TRICHY
***************************************************
Roll.No:
Name:
***************************************************
Subject    Subject    Maximum    Minimum   Marks
Code       Name       Marks      Marks     Obtained

***************************************************

thank u —Preceding unsigned comment added by Srividhyaathreya (talk • contribs) 13:44, 24 July 2009 (UTC)[reply]

We're not going to do your homework for you. If you write a program and it doesn't work, or if you have some specific questions, then someone might answer them. But we don't do all the work for you. 87.114.144.52 (talk) 13:51, 24 July 2009 (UTC)[reply]
You might also spend some time rereading the instructions, as printf() is a function, not a statement. --Sean 14:08, 24 July 2009 (UTC)[reply]
It sounds like they want you to use a for loop instead of printing the correct number of asterisks with a fixed-format. If you really must avoid printing the '*' symbol, you could putchar and do some ASCII math to calculate a value of '*':
// ...

int meaningOfLife() {
 int whatIsIt;
 whatIsIt = 6*9;
 return whatIsIt;
 }


int main() {
int i;


for (i=0;i<80;i++) {
 putchar(meaningOfLife() - 12);
 }
putchar('\n');
}
This is dramatically unnecessary, but it will get the point asterisk across. Nimur (talk) 15:48, 25 July 2009 (UTC)[reply]

Linux chmod, chown, chgrp

I need to do the following, recursively in a directory tree:

  1. chmod 755 for all subdirectories
  2. chmod 644 for all files
  3. chown www-data both for files and directories
  4. chgrp www-data both for files and directories

Could someone please suggest how to to this from the command line, in an easy-to-remember way? Thanks, --NorwegianBlue talk 14:27, 24 July 2009 (UTC)[reply]

  1. find -type d -exec chmod 755 {} \;
  2. find -type f -exec chmod 644 {} \;
  3. chown -R norwegianblue www-data
  4. chgrp -R somegroup www-data
87.114.144.52 (talk) 14:34, 24 July 2009 (UTC)[reply]
Thanks! find was what I was looking for. The chown and chgrp syntax doesn't seem to be right, though. Didn't work, and the manpage says nothing about specifying the original owner/group name. But
find -exec chown www-data:www-data {} \;
appears to work, and changes both user and group. Btw, why the need for a backslash before the semicolon? --NorwegianBlue talk 18:25, 24 July 2009 (UTC)[reply]
sh uses semicolon for syntactic purposes, so it needs to be escaped to make it unsyntactic or whatever. Unescaped it separates commands without a linebreak, eg 'rm ~/.bash_history; history -c; exit'. --91.145.89.22 (talk) 19:06, 24 July 2009 (UTC)[reply]
Thanks. --NorwegianBlue talk 19:07, 24 July 2009 (UTC)[reply]
I usually just use chown -R username:groupname directory. Never needed chgrp. Indeterminate (talk) 00:09, 25 July 2009 (UTC)[reply]
Missing from all these answers is the elegant answer chmod -R a+rX. This is not the same as a+rx which would add x permission for everybody on everything. The capital X adds x permission for everybody on those things that are already executable for somebody. In other words it's probably exactly what you're looking for. The creators of unix knew you'd want it so they added it for you, around 25 years ago. 69.245.227.37 (talk) 11:43, 25 July 2009 (UTC)[reply]
Brilliant! Thank you. --NorwegianBlue talk 15:58, 25 July 2009 (UTC)[reply]

Extending wireless range

At my sister's house they have a single wireless modem/router. The signal is pretty good downstairs and in the garden, but the signal is pretty weak everywhere upstairs; and in a couple of bedrooms the signal is so weak that a reliable connection cannot be maintained. The wirless point is located in a single storey extension towards the rear of the house, and I believe the quantity of pipes, wires and other stuff in the space between the ceiling and the floor upstairs is partially shielding the upstairs. We have already tried a wireless range extender but it wouldn't communicate with the modem/router - according to Linksys technical support, the range extender is only compatible with a limited number of their products and my sister's modem/router is not one of them. We could run wires to the upstairs, but doing so would require extensive drilling, disturbing newly laid hard floors, and the kids would all have to connect to the wired connection.

In a couple of weeks (while they are all away on holiday and I'm looking after their large number of pets), I will be doing some experiments, placing the wireless/modem in various locations to see if I can improve the situation upstairs. One alternative though is to replace the current wireless-G modem/router with a newer wireless-N product. My question is: if the receiving equipment (ie. laptops and various wireless cards) is still only compatible with the wireless-G standard, will we actually get any increase in the effective signal strength upstairs? In other words, would I be better off saving my sister the £80 that it would cost to get a new modem/router, and instead get a long drill to pass the cables upstairs? Astronaut (talk) 18:21, 24 July 2009 (UTC)[reply]


I wouldn't put to much into upgrading to an N standard only, partly as it requires any visitors to be bang up to date with technology. Do they really need the reception in the garden? One solution (which has worked for me) is just to put the whole router into a metal saucepan (literally), which would point the beam to the front and upstairs of the house, away from the garden. It may not penetrate whatever is blocking it already. Like pipes, as you suggest.
The Linksys WRT54G series is famous for being one of the most hacked devices of all time, and is popular as a repeater. As the firmware is GPL replaceable, you can strengthen the signal, and repeat things which Linksys really would rather you didn't. US$26.00 (including shipping) gets you a used one in the USA [6]. The Apple Airport Express is an expensive, although no-nonsense solution. Which unfortunately only works with its own stuff.
You are absolutely right not to start making any modifications to the house - which may well be redundant in five years' time anyway, as 3G and WiMax take over.78.149.86.100 (talk) 11:23, 25 July 2009 (UTC)[reply]
Get yourself some cardboard and some tinfoil, then try this.F (talk) 09:31, 26 July 2009 (UTC)[reply]

Internet on two computers

I have two computers, both with ethernet ports. My internet connection comes directly from the router via an ethernet cable, but there is only one port on the router so only one cable can be connected to it. How can I get internet on both computers? —Preceding unsigned comment added by 82.43.91.128 (talk) 18:40, 24 July 2009 (UTC)[reply]

I am not sure, but maybe something like this? Reading the product description I wonder if it is not more complicated than that though. Mike R (talk) 18:52, 24 July 2009 (UTC)[reply]
You need an Ethernet hub, or (better) a network switch. You plug the cable from the router into the hub/switch, and connect your PCs to the hub/switch. --NorwegianBlue talk 19:06, 24 July 2009 (UTC)[reply]
If what you have is really a router, and since a router creates a local network and gives out many IPs on the local network, then all you need is an Ethernet switch on your local network, that connects the router and the computers. However, it is highly unusual for a gateway router that is produced in the last 10/20 years to not have multiple ports on the local side (i.e. a built-in switch). It is also possible that what you actually have is a DSL modem or cable modem that does not include a router or includes a "fake" router (some DSL/cable modems do include a real router, but I would imagine that those would usually include multiple ports on the local side), which only gives you 1 IP. In that case, you would need to put get an actual router and put it between the modem and your computers. --Spoon! (talk) 19:08, 24 July 2009 (UTC)[reply]
Spoon! is correct. Another solution might be to turn on "network sharing" if the PC plugged into the router is a Windows PC, but you would need a second Ethernet port on that PC (perhaps via a PCI Ethernet card) in order to connect your 2nd PC to the first PC. I'd recommend a router with 4 ports on it, myself. Tempshill (talk) 23:58, 24 July 2009 (UTC)[reply]
The best way is to get yourself a new modem/router, making sure it is compatible with your connection to the internet (ie. phone or cable) and has sufficient ethernet ports for your needs. Stores like PC World have a selection from £30+. Astronaut (talk) 05:13, 25 July 2009 (UTC)[reply]


The idea about connecting the second computer to the first sounds good! Both computers have two ethernet ports themselves. How would I go about sharing the connection between them? And would the second computer act as if it was connected to the internet directly (ie would incoming connections like for gaming and stuff go to the second computer, or the first computer only?) —Preceding unsigned comment added by 82.43.91.128 (talk) 06:59, 25 July 2009 (UTC)[reply]

Are you running windows, if so this is easy - the first step is to connect the two computers using an ethernet cable plugged into the ethernet ports.
Instead of telling you myself try this link http://support.microsoft.com/kb/306126
Additionally you might want to set up a 'home network' which allows you to share files (and printers and stuff) between the two computers using the "shared documents" folders. If you want to try that search for "microsoft support home network"
If you are running vista the instructions may be slightly different - http://windowshelp.microsoft.com/Windows/en-US/Help/0c0f5981-6e3e-4912-a8d2-afc462b83d8c1033.mspx
It does work, though if you have any problems such as "limited or no connectivity" or "cannot obtain IP address" ask again.
If you don't have a windows OS then please say which type you are using.83.100.250.79 (talk) 11:29, 25 July 2009 (UTC)[reply]

Ok thanks I'll give it a go. Will the second computer be able to receive incoming connections (like a game or web server)? Or will those connections only go to the first computer (the one directly connected to the internet)?

Yes is should/will do all that. (Each computer gets a different address - like a telephone number and the signals always go to the computer that sent it)
Though if it doesn't work straight away you might need to adjust the settings -- specifically when you activate the "share this internet connection" there's a button "settings" on the same form. Once you've set sharing to on, you might (or probably will need to go to that box - usually the DHCP box needs to be ticked. It's simple to do. But see how you get on first. It may work straight away.83.100.250.79 (talk) 14:03, 25 July 2009 (UTC)[reply]

My question wasn't answered

[7]Vchimpanzee · talk · contributions · 20:06, 24 July 2009 (UTC)[reply]

If the back button is grey and not blue that means that there is nothing to go back to - ie no previous pages etc. This should only happen when the window has been opened for a new page, and the page has not been navigated away from eg no clicks on hyperlinks etc.
If you are getting a grey button, when their should be a blue one, then this is obviously a bug. If so can you replicate when the bug happens (technically you should probably contact MS support about this) - but first - can you describe how (exactly) you get to this situation - if you can I will try it, and see if the same thing happens.83.100.250.79 (talk) 21:38, 24 July 2009 (UTC)[reply]
Also can you link to a long file that this has happened in when editing.83.100.250.79 (talk) 22:44, 24 July 2009 (UTC)[reply]
I don't know. The library computers had this problem too. Then again, the gigantic emails sometimes wouldn't show up. That was on computers that I believe have been replaced. Let me try right now to duplicate what I did.Vchimpanzee · talk · contributions · 15:28, 25 July 2009 (UTC)[reply]
I did it. I should mention that my computer recently told me to get Internet Explorer 8, so I did.
The sequence was originally to go to [8] because I had seen his name somewhere in an article related to 9-11. I just wanted to see if he had a separate article, and boy, did he. I noticed his name had a hyphen in one place but not in another, so I decided both of those should match. Today I edited to suggest a split, because when I edited, it said the page was 159 KB at the top. I had read 35 KB was the recommended maximum. Today, I previewed, the template looked right, and I submitted. Then I tried to go back and this [9] was as far as I got. It said at the top of the page "Remember that this is only a preview; your changes have not yet been saved!"
If I can remember I'll try to document the sequence of actions with email. I'm very reluctant to do anything like that while I'm on my own computer.Vchimpanzee · talk · contributions · 15:43, 25 July 2009 (UTC)[reply]
As I sat and waited and waited, I remembered I'm using the second slowest speed available. The only speed slower is dial-up, and no one wants that because it ties up the phone and has other problems besides just being slow. The web sites show up faster on screen once I've gone to each one for the first time.Vchimpanzee · talk · contributions · 15:51, 25 July 2009 (UTC)[reply]
That effect is called caching - the pages show up faster because you are not downloading them; instead, your browser is showing you the copy you downloaded last time. Nimur (talk) 16:00, 25 July 2009 (UTC)[reply]
Actually, they're new pages from the same sites, but they do show up faster later.Vchimpanzee · talk · contributions · 16:37, 25 July 2009 (UTC)[reply]

Computer sputters and dies

My brother's computer, which generally has an issue with accumulating malware, is deciding to be a pillock. He can boot it up and log in A-OK, but the computer suddenly restarts within three minutes after doing so, regardless of the account he logs onto. He's certain there's no bugs on the rig because he ran MalwareBytes last night before he went to bed. He is running Windows XP. -Jeremy (v^_^v Tear him for his bad verses!) 21:43, 24 July 2009 (UTC)[reply]

Sudden restarts suck. Does this occur when you boot Windows XP up in safe mode? If so, and if I were in this situation, my next exercise to try to narrow down the problem would be to make a memtest86 startup disc, boot from it and run memtest86, eject the disc, and let it run its memory tests overnight. (Eject the disc so that if there's a restart, you'll know in the morning.) If it restarts during this overnight session, then you know that it's probably a hardware problem and not a software issue. Tempshill (talk) 23:56, 24 July 2009 (UTC)[reply]
He hasn't used safe mode yet, to my knowledge. -Jeremy (v^_^v Tear him for his bad verses!) 00:38, 25 July 2009 (UTC)[reply]
The computer's not rebooting in safe mode; just outside of it. He's told me he believes the problem stems from his McAfee install (courtesy of our Comcast internet setup), but that theory got killed when it rebooted again - and now it's being stubborn about the boot menu! SysRestore's also borked. -Jeremy (v^_^v Tear him for his bad verses!) 06:37, 25 July 2009 (UTC)[reply]
For a hoarder of malware, running just one scanner is nowhere near enough. He'd need to run at least Spybot and Ad-Aware as well, and any one of numerous good free anti-virus programs that are available. These between them will cover most of the spectrum of possible nasties. Then run RootRepeal to get any root kit virus, which is the second likeliest to cause unwanted restarting (after dial-home trojans which can't find their home planet).
Meanwhile, go to Control Panel > System > Advanced > Startup and Recovery, and turn off System Failure > automatic restart. This will let you see an error message, if any, about what is causing the restarts. - KoolerStill (talk) 13:12, 25 July 2009 (UTC)[reply]
Here's the error message: DRIVER_IRQL_NOT_LESS_OR_EQUAL. Also, he has three new desktop shortcuts to porn sites on his rig, ones that I'm pretty certain he didn't put on there. Safe Mode is also borking now, throwing up "PAGE_FAULT_IN_NONPAGED_AREA" errors. -Jeremy (v^_^v Tear him for his bad verses!) 04:02, 27 July 2009 (UTC)[reply]
You might also want to try running msconfig or Sysinternals Autoruns to disable the programs that automatically start up with your computer. If the rebooting stops after disabling those programs, you can try running them one at a time until the rebooting starts up again. Indeterminate (talk) 00:14, 27 July 2009 (UTC)[reply]
Doing System Restores won't get rid of viruses, partly because many parts of them are not where System Restore makes changes. Also being on the internet means the surviving parts will quickly call in the missing ones.(Porn sites and malware sites are often one and the same, so either can bring in the other).
(1) boot in safe mode (2) turn off the re-boot-on-error feature (3)turn off and unplug the internet while doing all the virus scans, at least 4 different ones (McAfee, Malwarebytes, Spybot, Ad-Aware), tho I'd run RootRepeal as well. Do it all in safe mode, because many viruses can hide from being scanned, if in Normal mode. Then run [www.ccleaner.com Ccleaner] to get rid of registry entries which trojans often leave behind (and scanners don't clear out), which will download new copies of their trojan if the old has been removed. You will need to download the scanners and burn them to CD on another machine, as trying on this one will be thwarted by the the viruses, trying to protect themselves. - KoolerStill (talk) 13:32, 28 July 2009 (UTC)[reply]
Safe Mode no longer works, Kooler (which means I can't put more AV programs on there), and he's already disabled the reboot on system error. Please read above your comment. -Jeremy (v^_^v Tear him for his bad verses!) 21:53, 29 July 2009 (UTC)[reply]

July 25

Internet causing computer crashes 2

Posted this earlier (just search for a question without the 2 at the end of title--) and someone suggested using Malware Anti-Malware so I finally got around to doing that (the computer I'm trying to fix isn't mine...) and it hasn't resolved my problem. Here's the original problem:

My computer crashes sometimes when I use the internet- completly crashes. Whatever site I'm on is open, nothing looks different, except everything is frozen and must turn off power using power button. It happens when I use Firefox, IE, on different websites (some don't even have flash or anything- last time I used the computer it crashed on espn.go.com)

I've ran Malware and it found a RougeDriveCleaner which I doubt caused the problem. Before Malware I ran I ran A-2 (free) squared and it found 2 viruses (Riskware.gen.Nero!IK, Trojan.BAT.Delfiles). After running A-squared I could use explorer.exe; before it would give me DEP and explorer would die everytime I tried to open it (even to view a folder.) Not sure if any of those are really problems but I deleted them anyway since they were in files and programs I didn't need. Ran some others-Avira(free), SuperAnti-Spyware (free) (it found 2 virus and about 300 tracing cookies also but unfortunatly its log somehow got erased..) I could post the HijackThis! log but I'm not so sure it would help. Given that it's sporadic I'm guessing that the actually virus (assuming its a virus) isn't always running. When it does run my computer crashes so I need to restart. Could there be a reason outside a virus? Computeridiot34 (talk) 00:22, 25 July 2009 (UTC)[reply]

I would run MalwareBytes AntiMalware and Spybot Search and Destroy (both free) and a free online antivirus scan such as Trend Micro HouseCall. This will least rule out the possibility of a virus or malware problem. Next I would then look at what programs are set to run on start-up using msconfig and services.msc (just use start --> run to execute these) as you may find there are some junk applications such as free screensavers etc that are causing the crash. Also, use Crap cleaner (free) to clear out all temporary files too. Rjwilmsi 09:56, 25 July 2009 (UTC)[reply]
It has 8 gb of temp. internet files but I'm not sure what that means. It has alot of work files downloaded as PDFs from online journals, etc. Things I can't delete. So are these 8 gb of temp. files causing the crashes? Computeridiot34 (talk) 23:35, 25 July 2009 (UTC)[reply]


I once had mine slow down to almost freezing, 6 times a day, at the same time almost to the minute. I traced it to a "normal" ad updater looking for (and finding) the website but being unable to update it (as I had it saved on the hard drive but not running in the browser). Some similar endless search may be using up all your CPU to the point of not letting any commands from you get through.
First delete your browser cache and cookies. Get and run [www.safer-networking.org Spybot]. Let it delete temporary files (these are internet cache type files, not things you've downloaded and saved with files names). Go to Advanced>Tools>System Startup. Clicking the right arrow bar will give details of known or suspected malware programs that start with the machine. Untick any suspicious ones, then reboot the computer and see if it behaves better. (If it does, go back to Spybot, untick them again and choose Delete from the top toolbar).
THEN boot into safe mode and run the anti-virus programs suggested by Rjwilmsi above. Delete anything marked BHO (browser help object) as many of these try redirecting to other sites, a good cause of internet problems.- KoolerStill (talk) 14:15, 28 July 2009 (UTC)[reply]

transferring files - tricky

What would be the easiest way to transfer a ~7 GB dmg file from a PC (Windows XP, desktop) to a Macbook (Tiger)? I have a 4 GB flash drive and a 2 GB SD card (which fits in a camera, conveniently).

I am assuming that splitting the file using 7-Zip and then transferring it would be the straight-forward solution. However, I was wondering if there is an "easier" way out. Is it possible to "open" the dmg on a PC as on a mac? I mean reveal the contents of the package so that I know what I need and what I don't ... thanks. Kushal (talk) 02:25, 25 July 2009 (UTC)[reply]

How about connecting them to the same network, and then transferring the files over AIM or something like that? Our Apple Disk Image article talks about the .dmg file format; in particular, you might be interested in the Apple Disk Image#Non-Macintosh section. --Spoon! (talk) 04:13, 25 July 2009 (UTC)[reply]

Thanks for the ideas. I got the ISO using the article you showed me (the Java program is awesome). I was wondering if I could change contents of the package and repackage it so I can run the dmg off of a 4 GB flash drive. Any ideas? Kushal (talk) 19:23, 25 July 2009 (UTC)[reply]

Archivers (7zip, WinRAR, etc.) can split archives into user-defined sized chunks which can then fit on your flash drive. --antilivedT | C | G 00:26, 26 July 2009 (UTC)[reply]

Antilived, thank you for the reply. I used 7 zip to create zip files and I used split and concat to join them but the resulting zip file was unusable. I am trying to do the split and join process again to see if it was some error on my part. I wish 7 zip was available on the Mac OS. Well, I will be back to report on the progress. Kushal (talk) 16:07, 26 July 2009 (UTC)[reply]

Jobs-for-life in the computer industry

Let's say you are a top-dog 3D CG programmer. To keep you from getting a pink slip, you have to learn lots of things during your career (i.e., new hardware, new instructions, advanced algorithms, improved software languages/architecture ...). Most abilities in the computer industry are becoming obsolete or inadequate in a few years thanks to the progress. What are the kinds of knowledge/expertise that have withstood the changes for the longest period of time?

I went to a public library last night. I noticed that some Z-80/8080 books published in the late 1970s and early 1980s are still being borrowed by people (due dates!). I think they are useful because many 8-bit processors are used in today's embedded systems. People are making honest money coding these 30-, 40-year-old things for a very large number of diversified employees.

Let's say you're a computer technician driving a time-machine to 2009 from the 1960s or 1970s. If you rule out those single-employee, limited-demand repairing jobs, are there any today's hard- software jobs that may demand your input? -- Toytoy (talk) 05:33, 25 July 2009 (UTC)[reply]

Many major organisations still use legacy systems developed in the late 1970s. They might have been ported to newer equipment or even newer operating systems, but if the program code is stable and it still does what is required then it could easily still be in operation. Those organisation are reluctant to lose their investment in years of development, for something new which might be years before it is as stable. Therefore you will still find organisations using a program written in COBOL and running on IBM mainframe systems; and they will have one or two people already on staff who are probably the only ones who know anything about how it works. Astronaut (talk) 09:26, 25 July 2009 (UTC)[reply]
Another thing to consider is to position yourself as the only one who knows how a particularly critical system works. For example, I used to know the guy who developed part of the communications system that is used in around 60% of the world's lotteries. It is a small role, but he is needed whenever a new lottery system is setup or an existing system undergoes a major upgrade. Astronaut (talk) 09:35, 25 July 2009 (UTC)[reply]
I think Z-80 programming is unlike COBOL. Being a COBOL programmer today is like working for a museum -- generally you don't make new things. In contrast, a new model of microwave oven may require new functions written in Z-80 assembly language from scratch. You probably can change your job because many industries still use these 8-bit chips. You job is not repairing a particular legacy system. -- Toytoy (talk) 15:25, 25 July 2009 (UTC)[reply]
You should think about computer theory (properly, "computer science", but that has become a loaded term). Programming has changed very significantly, and will continue to do so, but the structure and methodology of computer system design has actually not changed very much since its first incarnations. From the standpoint of hardware, the things which used to be reserved for very expensive mainframe computers are now available on every desktop, so this has enabled designers to rearrange the way they do computing; but overall, the same basic concepts of system analysis are the same. Being a critical thinker is more important than knowing the ins and outs of this week's latest fad scripting language. Nimur (talk) 16:07, 25 July 2009 (UTC)[reply]

Tracing of an email address

In the recent case of Darryn Walker, who was unsuccessfully prosecuted in the UK for writing an "obscene" story on a text-based story website, how was the author traced? The article says that he was "reportedly traced" through his email address, but I believe this was an anonymous Yahoo or Hotmail address. There was no IP address visible on the site. So how is it possible to trace an individual through their use of an anonymous email address? --Richardrj talk email 08:06, 25 July 2009 (UTC)[reply]

Even if the user has an anonymous e-mail address in which they provide no personal details when they sign up, if they access that e-mail address from their home computer the e-mail provider can log the IP address of their home computer, and the ISP that provides their Internet service can link that IP back to the bank account that pays for their Internet connection. In that way the user could be traced. Rjwilmsi 09:50, 25 July 2009 (UTC)[reply]
Thanks for that. So what are the privacy policies of email providers and ISPs in this regard? Do email providers log the IP addresses of their users, and if so, do they pass on those details to ISPs? And, to add the final link in the chain, do ISPs pass on those details to the police when they are asked to do so? --Richardrj talk email 13:52, 25 July 2009 (UTC)[reply]
They all do log the IPs and they pass them on to law enforcement agencies with subpoenas, usually. --98.217.14.211 (talk) 14:07, 25 July 2009 (UTC)[reply]
Depends on the country you are querying about, and our answer depends on whether the police/government behave according to law or not. Tempshill (talk) 05:41, 26 July 2009 (UTC)[reply]

Man day in software

If a software project is said to be completed in 20 man days, does it mean the entire project was completed by 1 person in 20 days? Or is it that x number of people worked on this project for 20 days? I would appreciate a quick reply. Thanks!--117.196.133.19 (talk) 09:21, 25 July 2009 (UTC)[reply]

It means the equivalent 20 days of work, if carried out by one person. Whether it was in fact 1 person for 20 days, 2 for 10, or 40 people for half a day is not specified. See man-hour for more. Rjwilmsi 09:44, 25 July 2009 (UTC)[reply]
In project planning, a man-day is the amount of work done by one person in one day (I'm surprised we don't have an article about that). The day is usually defined as 6 - 7.5 man-hours depending on the hours of work and the length of the lunch break. A man-year is typically 240 man-days (ie. it excludes weekends, vacations, sickday). In your example above, it means 1 person worked alone for 20 days, or 2 people worked together for 10 days, or 4 people worked together for 5 days, or 20 people worked together for 1 day. Astronaut (talk) 09:46, 25 July 2009 (UTC)[reply]
We have man-hour, and man-week and man-month redirects to it (it's more generally written). So I've redirected man-day to man-hour; that article could do with a more generic name, but hypothetical worker abstract work units doesn't trip off the tongue. -- Finlay McWalter Talk 13:52, 25 July 2009 (UTC)[reply]
I vote for hypothetical worker abstract work units to be made an article, or at least redirect to the other one.
Nobody has linked to the Mythical Man-Month yet? This famous book, written by an IBM software project manager, blasted the idea that (1 person x 20 days) = (20 people x 1 day), or that software projects can even be measured in these terms at all. Nimur (talk) 16:09, 25 July 2009 (UTC)[reply]
The classic rebuttal is the case of pregnancy. Technically it might be ~9 man-months of effort, but 10 men (or even 10 women ;-) are not going to be able to produce a baby in under a month, no matter how hard they try. -- 128.104.112.87 (talk) 18:28, 25 July 2009 (UTC)[reply]

Hooking speakers up to laptop

I just got a set of 5.1 speakers, because I had "points" to redeem through Westlaw and it seemed like the best thing of all the crap in their little online store. I don't particularly need 5.1 sound, just basic stereo with the sub would be fine with me. The speakers have three different colored male cords to hook into your computer/TV, but my laptop has only one output thing for speakers/headset. Can I just plug the black cord into my laptop or could that cause problems somehow? I don't want to buy an external sound card or anything fancy. If these speakers won't work I'll just sell them or give them away. Calliopejen1 (talk) 14:16, 25 July 2009 (UTC)[reply]

The "Green" is color code for primary (stereo) speaker. Plug that into the "headphone jack" for the standard sound experience. You can also buy external stuff (for example, a USB attachment) which will have a breakout for each speaker. Remember always, though - the sound quality is dictated by the weakest link on your audio chain - your source material, your laptop's audio card, your cable, your speakers, etc. If you're watching web TV, there's only stereo sound anyway, so you aren't missing anything. Nimur (talk) 16:13, 25 July 2009 (UTC)[reply]
None of those plugs should cause problems, but you probably want to plug in the primary speakers, not the side-speakers. Nimur (talk) 16:15, 25 July 2009 (UTC)[reply]
Ok thanks! 209.6.22.105 (talk) 18:29, 25 July 2009 (UTC)[reply]

server blocked by nat

How can I access a web server on a computer which is connected to my local network via NAT? Is there like a free program which you could run on both computers to let them speak to each other?

Do you have administrative access on the NAT? It sounds like you need port forwarding. Otherwise, you could try setting up a VPN and tunneling connections, but this is not easy. (My lousy experience with OpenVPN last summer led me to conclude that commercial VPN software is worth the exorbitant costs that they charge large organizations). Nimur (talk) 16:17, 25 July 2009 (UTC)[reply]
Wait, now I'm confused - you are already on your local network? Is the computer already running web server software, like Apache (server)? Then, you should be able to use the local IP address or DNS name of that computer directly. The NAT should only matter if your client is outside the local network. Nimur (talk) 16:19, 25 July 2009 (UTC)[reply]
I tried entering "localhost" into the browser on the computer without the server but it didn't work. The other computer with the server has the same ip address as this one, I checked on http://showip.net Reg556 (talk) 16:46, 25 July 2009 (UTC)[reply]
You should read Network address translation. Because of the NAT, your computers appear to have the same IP address, but they actually have two separate, local addresses. If you are using a home router, these will usually be something like "192.168.1.100" (but it depends on your DHCP settings and the type of NAT/router/DHCP server you have). You need to find the actual, local IP addresses. If the systems are running windows, you can check your ip settings from the command line: Start Menu > Run > cmd, and type ipconfig /all, which will list your local IPs. On Linux/Unix, you can type ifconfig in a terminal. "localhost" will not work - it always refers to the current machine, and does not perform any transactions over the network. Nimur (talk) 17:04, 25 July 2009 (UTC)[reply]
What kind of "access" do you require? Can't you just point your browser to the address you get from your showip.net or whatever? --Spoon! (talk) 18:09, 25 July 2009 (UTC)[reply]
No because I get the same ip address from showip.net for both computers. I've tried all these suggestions. Is there not a simple program I could install on both computers that would talk to each other and make the link for me?
I think your problem is still that you have not found the local ip address. Any "what-is-my-ip" website will be totally unable to find this for you. You need to check the machines or the router to see how the NAT is mapping individual computers to local IP addresses - note that this is not the same IP you see on the IP look-up website. That is the external IP address, assigned to your cable-modem or DSL modem. The NAT maps that back to different, unique local IP addresses for each computer on your network. You must use this local IP address to connect; or you can set up port-forwarding on the router to do the mapping. I described a method above for finding the local IP - do you need more help with that? Nimur (talk) 22:19, 25 July 2009 (UTC)[reply]
I think I do need more help, I tried entering ipconfig /all and it returned a list of ip address for things like gateway and stuff. I tried entering each ip address into the browser but none of them connected to the server on the other computer Reg556 (talk) 05:22, 26 July 2009 (UTC)[reply]
We have an article on ipconfig. Take a look at this screenshot. You want to find your IP address (located directly above the Subnet). (There is a lot of other information you do not need). The IP listed here is the local IP address of the machine. While on the local network, this is the best way to access the machine. Find the IP address of the server; try connecting to that address using the browser on the other (client) machine. If it is still not working, verify that the server is actually on (both the server hardware and the server software). Also check if there is a software firewall on the server, which might be blocking access. Check if you can access the server while you are sitting at the server's terminal. Sometimes a network ping is the best way to check connectivity; that lets you isolate networking trouble from server-software trouble. Note that software firewalls can also interfere with Ping. Nimur (talk) 16:31, 26 July 2009 (UTC)[reply]

What is this system called?

[10] Under "Customize results". In Firefox 3, you can adjust the properties of the address bar in an about:config setting. It is only one value but that one value can be used to make many different combinations of properties. The system (the blog author calls it a bitmap, but I can't find any other references to it) uses numbers which are powers of 2 to represent the options. Once you choose which options you want, you add up the values to get your combination. 24.6.46.177 (talk) 16:42, 25 July 2009 (UTC)[reply]

Or, even better, you "or" them together (so that noting bad happens if you "add" an option already "on"). This technique is very common in programming. But I do not know of any name for it... --Andreas Rejbrand (talk) 17:01, 25 July 2009 (UTC)[reply]
Yeah, it's either called a bitmap or a bit field. It's an extremely common pattern in systems programming and computer-hardware, where one bit (or several adjacent bits) represents a single value, and so a given byte or word compactly stores a bunch of values. -- Finlay McWalter Talk 17:03, 25 July 2009 (UTC)[reply]
Yes also see Flag word - "word" here means a collection of bits (0 or 1), and flag - see Flag (computing) - presumably from the ability of a flag (realworld) to be either up or down. (Potentially "flag word" and "bit field" should be merged - if anyone want to tag them?)83.100.250.79 (talk) 17:22, 25 July 2009 (UTC)[reply]
Yes, flag word is better, although it seems to talk only about cases where each logical unit is a single bit. It's common to find cases like:
              bit0   - output enable/disable
              bit1-3 - output gain (0..7)
              bit4   - output buffer interrupt enable  
              bit5-6 - output buffer interrupt threshold (0..3)
              bit7   - reserved
... and we don't really have an article that matches this (very common) pattern. I don't think bitfield and flag word should me merged. Flag word is the hardware thing, bitfield a software construct. While you'd often use a bitfield to address a flag word, you could also do it just with masks and shifts, and equally a bitfield can be used as a purely software construct (as in the case the OP is talking about). -- Finlay McWalter Talk 17:39, 25 July 2009 (UTC)[reply]
I can't find the article either, I've added each to the 'see also' section of the other and left it at that.83.100.250.79 (talk) 18:39, 25 July 2009 (UTC)[reply]
While we're naming alternative terminology, these are sometimes called bit vectors or registers, especially in hardware description languages like verilog and VHDL that support nonuniform word lengths. Nimur (talk) 03:22, 26 July 2009 (UTC)[reply]

Subscriptions to a blog

Is there a way to set up a Blogger blog so that people can just click a link to be notified of new posts to the blog via email? I see that a reader/subscriber can do this if they use Google Reader but that may not be what everyone uses for their email. And it means that everyone has to go through the trouble of signing up with a special service just to find out about updates to the blog when they could just visit the blog and find out. Alternatively, is there a blogging service that does allow users to subscribe in a way like what I want? Dismas|(talk) 17:43, 25 July 2009 (UTC)[reply]

It's hard to imagine a practical implementation of that that wouldn't require a bunch of steps from the user, which would amount to a signup. First they have to type in their email address, then probably fill out a CAPTCHA (to avoid the system from being used to mailbomb people), and then reply to a confirmatory email (again to avoid the system from being abused to sign up unwitting third parties to huge lists of unwanted chatter). That's pretty much the same sign-up process for a regular RSS aggregator like Bloglines or Google Reader, so they might as well just use one of those and get all the associated flexibility. Now you could do this as a client side feature (with an RSS reader program or a firefox plugin), but that's obviously not a zero-install-zero-setup option either. -- Finlay McWalter Talk 18:02, 25 July 2009 (UTC)[reply]
Okay, so submitting, going through CAPTCHA, and confirming is fine. If the instructions included going through a signup or download of an aggregator, then I see that as too much complication that people may not be willing to go through for a single blog. Dismas|(talk) 20:09, 25 July 2009 (UTC)[reply]
Doesn't Google Reader allow you to configure an RSS aggregator to send email updates? This only requires that the blog supplies RSS, and that you are willing to use Google's service. Nimur (talk) 03:29, 26 July 2009 (UTC)[reply]

converting raw fils

So I've got a dslr and am shooting in RAW (good), and am taking pictures of steam engines. I'm having a problem with the exposure - or rather converting the RAW file to jpeg. The problem is that the subject is pretty dark, but the sky is full of nice fluffy clouds. By moving the exposure slider up and down I can either get picture of black engine with completely washed out sky, or a nice picture of the clouds but an underexposed subject. I can try hdr, but that seems to produce dramatic images rather than realistic looking images. Ideally I want to open the raw file, select different areas of the and apply different exposure values to those areas only but ensure that the joins between areas are smooth. I only have ZoomBrowser EX and Digital Photo Professional. But do I need Photoshop Elements to do this? —Preceding unsigned comment added by 86.144.124.80 (talk) 19:51, 25 July 2009 (UTC)[reply]

The HDR images you see online are mostly gaudy examples where they've taken things to an extreme - it is possible to use the technique with a degree if subtlety (e.g. some of the photos in this set - http://www.flickr.com/photos/phototoasty/sets/72157594225970774/) and it seems almost everyone oversaturates their HDR photos (all the better to emphasise their bad trip appearance). Anyway, if you want to be editing the files yourself, you'll find that The Gimp and dcraw will read the various RAW formats for many popular cameras (RAW isn't a format per se, just whatever data comes out of a particular camera's sensor, so you need software that knows about your camera). More stuff is listed at raw image format#Software support; with those you should be able to convert your camera's RAW (assuming it's supported) into TIFF or PNG and you can edit that in whatever you're comfortable with. -- Finlay McWalter Talk 20:50, 25 July 2009 (UTC)[reply]
Another good software to do this is hugin (software). Export your RAW file to different exposures (eg. +1, 0, -1), and follow this tutorial (ignore the stitching part, you don't need it). It creates some quite subtle HDR images but tends to require some contrast enhancement. --antilivedT | C | G 00:21, 26 July 2009 (UTC)[reply]

Can GIMP open RAW files? GIMP is a free, free alternative to Photoshop. Nimur (talk) 03:33, 26 July 2009 (UTC)[reply]

The OP needs a program which can process the colour depth present in the RAW files, which is more than 8 bits per channel. The GIMP is limited to 8 bits per colour channel, whereas Photoshop can process 16 bits per channel. I don't think the SE version of Phohotoshop does 16-bit per channel color, though. An option would be to convert the RAW files to high-color-depth TIFF files with dcraw, and read these with Photoshop. There is a GIMP fork called CinePaint which can handle high colour depths, but it's only available for Linux and Mac, not for Windows. I've tried it on a Debian machine (at SteveBaker's recommendation), but found it rather unstable, and it was later removed from the repositories because of its bugginess. The dcraw page has a link that might be of interest, I followed it, ended up here, and read about the programs Zero Noise and Perfect Raw. I haven't tried them, but intend to when I get the time. Unfortunately, some of the info appears to be in Spanish only. --NorwegianBlue talk 07:55, 26 July 2009 (UTC)[reply]
This article http://www.wikihow.com/Take-High-Dynamic-Range-Photographs and this http://qtpfsgui.sourceforge.net/about.php program may also be of interest. --NorwegianBlue talk 21:43, 26 July 2009 (UTC)[reply]

Broken link

http://en.wikipedia.org/wiki/Sonoran_Desert - this page was accessible up until about a week ago. Now it just generates page load errors. —Preceding unsigned comment added by Clhowson (talk • contribs) 20:14, 25 July 2009 (UTC)[reply]

Works for me. Try clearing your browser cache. -- Finlay McWalter Talk 20:52, 25 July 2009 (UTC)[reply]

Core 2 Quade 9400 and Vista 64 SP 1

Recently, I have upgraded my hardware. My new processor Core 2 Quad 9400 requires Vista 64 bit SP1. I found this info from its official. Right now I'm using XP SP 2. Should I install Vista 64 bit SP1 for better CPU Performance or stick with current XP SP 2. I have not used Vista before. My motherboard is 750i SLI Nvidia Geforce and Graphics card is Sapphire ATI 4890. Any suggestion? —Preceding unsigned comment added by 119.30.36.44 (talk) 21:05, 25 July 2009 (UTC)[reply]

Surely it doesn't require vista; IA64 will run 32bit OSes perfectly fine. For an ordinary user, the most obvious advantage of switching to a 64 bit OS is that it allows you to address more than 4GB of RAM; while some operations are certainly faster, some others are (in practice) slower, as the wide IA64 instructions are larger, making for poorer use of cpu cache. Assuming everything is working for you now, and there's nothing that you need Vista for, personally I'd stick with XP until Windows 7 comes out (it seems to have all of Vista's improvements and few if any of its demerits). -- Finlay McWalter Talk 21:24, 25 July 2009 (UTC)[reply]
If you have something that requires Vista, get something else. HalfShadow 21:28, 25 July 2009 (UTC)[reply]
To the best of my knowledge, Intel Core 2 CPUs implement x86-64 rather than IA-64. -- Meni Rosenfeld (talk) 21:04, 26 July 2009 (UTC)[reply]
Your CPU does not require Vista. You can run XP, Windows 2000, or Windows 1.0 if you feel like it. Tempshill (talk) 05:38, 26 July 2009 (UTC)[reply]
It's possible that the Core 2 Quad 9400 "requires Vista 64-bit SP1" in the sense that it will not work properly in the original 64-bit Vista because of some compatibility bug that was fixed in the service pack (SP1). In principle you might have hardware (not the CPU) that only has drivers for Vista 64-bit, but almost certainly you will be able to find 32-bit XP drivers for everything. -- BenRG (talk) 13:16, 26 July 2009 (UTC)[reply]

any way to delete iPod content from WITHIN iPhone?

So my iPhone is full but I wanna download some apps. Is there any way I can DELETE some of my music from WITHIN iPhone (ie without connecting it to anything).

Thanks!!!

ps. the reason i'm asking is that i just have an old computer with usb 1, all this content is from someone else's computer but I don't want to lose it. thanks. 82.234.207.120 (talk) 21:22, 25 July 2009 (UTC)[reply]

Don't think so. The whole point of having to connect to a computer is so nothing gets deleted accidentally. HalfShadow 21:24, 25 July 2009 (UTC)[reply]
Can you do it if you have a shell on the iPhone?F (talk) 09:35, 26 July 2009 (UTC)[reply]

Fixed /dev/ path for external USB drive

I'm using Kubuntu. Each time I plug in my external USB drive, it gets a new path in /dev (e.g. /dev/sda1 one time and /dev/sdb1 the next). How do I set it to always have the same path? NeonMerlin 21:34, 25 July 2009 (UTC)[reply]

You can hack something in udev, but the easy way is not to refer to it by its /dev/sdXN name, but by its UUID, which is fixed. Try this - with the USB disk absent, ls -l /dev/disk/by-uuid > /tmp/foo. Then insert the disk, wait until it's recognised, then type ls -l /dev/disk/by-uuid | diff /tmp/foo - . This will show you the UUID of the disk and its dev-uuid. So now, rather than refer to it as /dev/sdc1, refer to it as /dev/disk/by-uuid/ABCD-1234 or whatever. You can also statically mount devices with mount or /etc/fstab by UUID (search their respective man pages for UUID for the syntax). I mount all my local hard disk partitions this way - this way I can rearrange the SATA cables or whatever and the disks all still mount correctly in the places I want. -- Finlay McWalter Talk 22:37, 25 July 2009 (UTC)[reply]
Hey, I didn't know you could mount drives like that. Thank you, that's a great tip. APL (talk) 17:56, 26 July 2009 (UTC)[reply]

July 26

latest version of IE

Why does the lastest version of IE not support Unicode in the bottom at the status bar and in the address bar too? Firefox can display proper characters instead of escape codes! Is it because the folks at Microsoft just can't be bothered? I mean, how much effort could it possibly take to do that???

Duomillia (talk) 01:00, 26 July 2009 (UTC)[reply]

No, you screwed something up on your system, not Microsoft. Unicode characters display great in my browser. For example, when I type this into the address bar, it loads fine: http://ουτοπία.δπθ.gr. But why are you asking us, anyway? Start a thread in a Microsoft Technet or Connect forum, if you're so sure that it's a bug. They're actually pretty good with fixing bugs if you make any kind of effort to contact them. By the way: In my experience, most people don't even know the status bar is there. The latest version of Internet Explorer is actually over-engineered in my opinion -- not the opposite.--WinRAR anodeeven (talk) 02:59, 26 July 2009 (UTC)[reply]
This is a deliberate feature intended to prevent phishing attacks. See IDN homograph attack. Internationalized domain names were not designed very well. Firefox also displayed decoded names in the address and status bars for a while. According to the article they now use a top-level domain whitelist. There's an IE option "always show encoded addresses", but I recommend you leave it off unless you use IDNs a lot. -- BenRG (talk) 11:03, 26 July 2009 (UTC)[reply]

J2EE programing

please suggest me a wonderful book or a good tutorial or website or anything which can teach me J2EE programming and HTML thoroughly...assuming that I have a basic knowledge of C,C++,JAVA.I am in great need to learn it.pl help —Preceding unsigned comment added by 117.193.128.204 (talk) 04:26, 26 July 2009 (UTC)[reply]

Java EE, like the rest of the Java technology platform, has no better resources than the Official Sun Java EE technology guide, including source code, example projects, tutorials, and all the software and tools you need to make a project. Download GlassFish and run the PetStore example application. You can find tutorials here: Java Pet Store. You can download all the tools here (check for your operating system and language version). Nimur (talk) 05:26, 26 July 2009 (UTC)[reply]
Regarding HTML, I use the W3 official specification as my preferred reference. If I were just starting out, I would try reading the HTML article on Wikipedia, which is a little more user-friendly. In general, HTML is best learned by viewing examples; once you have the basic tags, simply start viewing source for web pages you are browsing to take a peek under their hood. A lot of modern web pages use very complicated HTML combined with scripting and embedded plugins, so they can be intimidating source to read; but it's a good idea to get a feel for how the pages are put together. Nimur (talk) 05:32, 26 July 2009 (UTC)[reply]

Annoying Freeze

Every now and then I get sudden freezes. The computer completely locks-up. I cant move the mouse or use keyboard everything is frozen, you know what I mean. ALL i can do is restart pc. Another problem is desktop icons, start menu, images (also in internet image) gets broken into pieces and I can't see image properly. It looks like image gets scratched.

First I thought this was a cpu problem, then motherboard, then graphics card, then ram, hard drive etc. I just cant figure it out. It happens when I am on minefield, IE (latest version) firefox 3.5, when I am logging in at facebook. Even this problem persist after closing browser ! This was an issue before as well I don't know what is causing this freezes. If I play any music when I'm on browser the sound also gets crashed (screaming like carrrrr...). These are happening after upgrading my hardware. I am using XP SP 2. My processor is Core 2 Quad 9400 (which requires Vista 64 bit SP 1 though) and motherboard 750i SLI Nvidia Geforce, RAM 2 GB (800MHz), Sapphire ATI 4890 1 GB, Full tower Chassis (Tharmaltake Xaser VI). I have several XP SP 2 OS. The Current XP SP2 that I'm using, bought it 4 years ago.

How can I rectify this problem?--119.30.36.47 (talk) 14:36, 26 July 2009 (UTC)[reply]

The problem sounds like a hardware crash due to overheating. I would perform any available BIOS and/or graphics driver updates, then use a hardware monitoring tool like HWMonitor (there are various free ones) to track down the problem. Rjwilmsi 17:28, 26 July 2009 (UTC)[reply]
  • But Sometimes I can move mouse for a while then it suddenly stopped again. You said"I would perform any available BIOS and/or graphics driver updates. My BIOS and graphics card are already updated (Correct me if I am mistaken). I have used HWMonitor. It shows only temperature after the crash. GPU Core is 61 *C to 63 *C. My full tower chassis has 5 collar fan (including two 140mm turbo fan) inside to provide sufficient airflow. What else I can do?--119.30.36.33 (talk) 18:17, 26 July 2009 (UTC)[reply]
63C is too hot. Try this - open your case and blow an ordinary room fan into the case to cool it down further. Your GPU should get below 50C... see if that helps. Either your case airflow is not optimal or helping the GPU, or there's something faulty with your graphics card. Sometimes these weird freezing/rebooting problems are due to the power supply which is faulty or dusty and your CPU is not receiving clean power from it. My last two PC problems were: playing video rebooting PC (replaced GPU) and random rebooting doing anything (replaced and upgraded power supply). Good luck. Sandman30s (talk) 09:55, 27 July 2009 (UTC)[reply]
  • I forgot to mention that this freezing problem occurs only when I run my system for 8 to 12 hours or sometimes 5 hours.You said, "blow an ordinary room fan into the case to cool it down further". Are you suggesting me to add another GPU Cooling fan in additional slot (sorry for my English)? The chassis contains some extra slot for fans. One more thing is that my motherboard contains two GPU Slots. The First slot (where graphics card is attached) is located a bit above to turbo VGA cooling fan and does not get proper air. Second slot is closely located to the cooling fan and gets much air flow. I am thinking to remove Graphics card from first slot and attach it to second slot. I notified the hardware technicians (where I assembled my systems) about my intention but warned me not to do that as the second slot is for another graphics card and if the first slot does not work. They also suggested me to disable system restore point and schedule scanning of internet security to prevent this freezing state. Should I proceed to second slot? Suggestions ? --119.30.36.39 (talk) 13:32, 27 July 2009 (UTC)[reply]

Update: I have checked the BIOS. It shows CPU temperature is 30 to 31 *C and System temperature is 40 to 41*C.--119.30.36.42 (talk) 15:01, 27 July 2009 (UTC)[reply]

No, I mean: open the case. Take an ordinary electric powered fan that plugs into the wall socket. Plug it in. Turn it on. Face it towards your open case and your computer will get the benefit of cool air blowing directly onto the GPU's and everything else. This is a TEST. If it works, it means you have a heating problem and then you either need to swap your card/s or get better cooling in your case. Sandman30s (talk) 15:41, 27 July 2009 (UTC)[reply]

Ok. But is temperature from BIOS Ok or not. I should have mentioned that this freezing problem usually occurs when I am on online (after 12 pm) for 5 to 8 hours. Yesterday I run my system for 10 hours and nothing was happened. It seems that it only happens while I'm on online (I tested with all browser). I use Modem for net connection. If It's not overheating issue what else can it be? Is modem incompatible with system (which causes this freezing)? --119.30.36.53 (talk) 12:15, 28 July 2009 (UTC)[reply]

Windows 7 Torrent

I've been having a discussion with some friends and they don't believe that Windows 7 is already up on torrent sites (a full version) and I'm sure it must be. Though at the moment we're unable to access those sites ourselves. I was curious if someone could confirm whether it appears that full versions of Windows 7 are available to torrent. Of course, I wouldn't ask someone to link to them, just a confirmation that they themselves have seen it (and if you have used it, if it was for real). Thanks! 71.75.71.102 (talk) 14:47, 26 July 2009 (UTC)[reply]

Since even before the beta of Windows 7 became publicly available there have been versions of Windows 7 leaked to torrent sites. However, some of these leaked versions are known to have been tampered with or to contain malware and I would not recommend anyone try to download and use any of the leaked versions. Consider trying out the Release Candidate instead (Which expires June 1, 2010, with bi-hourly shutdowns beginning on March 1, 2010) or waiting for the final version of Windows 7 which you can pre-order now.--Xp54321 (Hello! • Contribs) 17:05, 26 July 2009 (UTC)[reply]
You could also use this[11] Mac Davis (talk) 00:45, 28 July 2009 (UTC)[reply]

Is this the end of my Nintendo DS?

As the title suggests, I'm worried that my DS going to become unplayable and I need some links or advice if the thing is on it's last legs or not. My problem is that when turning the DS on, it will be okay for a bit, then have some odd display problems (I can see something that looks like a brownish circuit board through the screens) I took out both of the games I was playing to see if they were the problem, but they weren't, the problem persisted even with both slots empty. If I plug in the headphones, the top display stops being wonky, but the bottom screen remains odd.

Another thing about the DS is that it got fried once by getting drenched by an exploding pop bottle, but when it dried out it worked just fine for a few months. Suddenly the speakers stopped working. I didn't really care, it worked fine with headphones plugged in so I left it and enjoyed it for no problems . Two days ago, the speakers suddenly began working again. And now today I'm getting these display problems. I'm not sure if the display and speaker problems could be linked, but it might explain why the display is okay on the top screen with the headphones plugged in.

So really, all I want to know is if my DS is doomed to die and I need to start looking for a new one. The display doesn't bug me that much, so if it'll be okay how it is and not die, I won't bother replacing it. Also, I can't really send it in for repairs because I have a feeling the pop explosion a year ago is what caused it. Also this DS is an original one (Not a Lite nor a DSi) and is about 4-5 years old now, it's warranty is probably gone by now. Thank you for your time. 69.157.106.254 (talk) 14:54, 26 July 2009 (UTC)[reply]

It is very likely that the circuits are corroding, and will die a slow death. Sorry. You could try cleaning its innards with distilled water or alcohol. (Do not use tap water.) That may help, but it would have helped more back when the accident first occured.
It's also possible that there is still soda on the board and it's causing intermittent short circuits. Again, that might be helped by cleaning it.
There is no way to know for sure, but either way I suspect that if you don't take it apart and clean it (No tap water!) it will slowly get worse. APL (talk) 17:54, 26 July 2009 (UTC)[reply]
Oh well. I wished I'd known about cleaning it when the whole thing happened a year ago. Thanks for your help. I'll give cleaning it a shot and start looking around for discounts for when the poor thing kicks the bucket. I'm just glad it managed this long, now with the DSi out, getting a DS will be cheaper. Thanks again! 69.157.106.254 (talk) 18:10, 26 July 2009 (UTC)[reply]

Resources for a beginning teenage programmer

I'd like to get my Nephew into development, probably with an ultimate goal of working in a MS or web environment (.NET I suppose?). He's a beginner so I guess the question is what's a good starting point or general introduction. Are there any interactive tools you can buy that can take you through lessons/labs? I don't know much about development but I'd be interested in something that's more focused on doing rather than reading...he's 14 so I'm nor sure how much time he'd spend sitting around just reading. Thought? Thanks...RxS (talk) 15:09, 26 July 2009 (UTC)[reply]

I'm 21, and I learned in Visual Basic around 14, but that's on the decline now. I'd recommend something like Java, and this is a tutorial I particularly enjoyed because it's more interactive. [12]. Hope that's useful. 71.75.71.102 (talk) 15:29, 26 July 2009 (UTC)[reply]
I'd suggest one of the Game engines, such as Game Maker. I've used them with teenagers before, and they have the advantage of being interesting to program in quickly. While the language isn't much use itself, the principles are. Alice is a good beginner's language as well, with quick rewards, but I'm not sure if it has a clear path for where to go once you get the hang of it. It does have nice tutorials, though. For serious languages, I'd go straight to C# or Java. I'd add that the main aim is to keep it interesting from early on, and part of that is making the projects interesting. - Bilby (talk) 15:44, 26 July 2009 (UTC)[reply]
That's what I'm mainly interested in, fairly quick engagement/visible results that provide a good foundation and path to more advanced concepts in current technology. Thanks! RxS (talk) 15:54, 26 July 2009 (UTC)[reply]
It sounds like Java is a good starting point, are there any other resources available? The one linked above seems to give Vista/IE 7 fits. Thanks again...RxS (talk) 17:05, 26 July 2009 (UTC)[reply]
http://math.hws.edu/javanotes/c3/index.html this link causing problems - I'm on IE7 and it seems to work perfectly.? Seems such an innocuous site.
Resources for learning java? - sun has one - tutorials, plus lots of documentation - just search for "sun java", and you should find it. I believe they have a 'young programmers' section or program as well. Here's a start page http://java.sun.com/new2java/learning/young_developers.jsp Possibly the first few sections are aimed at younger children.83.100.250.79 (talk) 22:10, 26 July 2009 (UTC)[reply]
If they have no programming experience before I would probably recommend something else - probably python (programming language) (since everyone else does) - it's pretty much the equivalent of what BASIC was 20 years ago - it's easier to get into for a first language (yet it's still a proper language - with real world uses). Though it might be just as good to start in a slightly harder language straight away - I certainly found it hard going from 'beginners or educational' languages to 'proper languages' - the easy ones can cause laziness.83.100.250.79 (talk) 21:25, 26 July 2009 (UTC)[reply]
Most Universities (in US/Canada) seem to start off with Java, as did my high school; it really wasn't too bad as a starting language. As far as visible results go, Robocode is pretty fun. -- Consumed Crustacean (talk) 01:16, 27 July 2009 (UTC)[reply]
I'd like to recommend Robocode as well - it's a good system for learning some prinicples fast. I recommend it to the first years as something for them to practice with. Just keep in mind that Java itself requires a fair bit of theory before you can code anything of value. The language is very nice, but unless you use something like NetBeans the GUI can be complex to learn, and the OO side of things is tricky. Which, of course, is part of why we teach it. :) I normally recommend BlueJ as a first IDE, but that's mostly because of its educational value, so it might not be useful at home. - Bilby (talk) 01:29, 27 July 2009 (UTC)[reply]

Parallel Port Programming

I would like to know what a parallel port programming is and how to use it in programming of microcontrollers.i.e.in robotics.Pl suggest some good ebook or website where I can get all the info on this. —Preceding unsigned comment added by Gd iitm (talk • contribs) 16:43, 26 July 2009 (UTC)[reply]

Perhaps this web site can help. 91.32.118.182 (talk) 18:13, 26 July 2009 (UTC)[reply]
See the article Parallel port. But note that manufacturers have stopped providing parallel ports on their PCs. Cuddlyable3 (talk) 21:14, 27 July 2009 (UTC)[reply]

Equivalents of pointers and/or dereferencing in scheme ?

I'm doing things like this: 

> (define a 10)  
:ok
> a
:10
> (define b '(1 a 2))
:ok
> b
:(1 a 2)
> (cadr b)
:a

Basically I can't work how to make the "a" in (1 a 2) act as a variable, and by extension how to control whether it's evaluated, or left as "a" e.g. Are there commands to do stuff like this in scheme? e.g.: 

> (define a 10)
> (pointer a)  ie the command I'm looking for
:a
> (dereference (cadr '(1 a 2)))  the other command I'm looking for
:10

?I must be conceptualising the whole language wrong I suspect?83.100.250.79 (talk) 19:31, 26 July 2009 (UTC)[reply]

I think what you're looking for is quasiquote and unquote:
1:=> (define a 10)
a
1:=> (define b `(1 ,a 2)) ; equivalent to (define b (quasiquote (1 (unquote a) 2)))
b
1:=> b
(1 10 2)
1:=> (cadr b)
10
24.76.174.152 (talk) 20:10, 26 July 2009 (UTC)[reply]
Nearly (or possibly) - however if I do
> (define a 99)
> (define b `a)
> b
a
Which is better than before (ie not 99)
But how do I get
> (func b)
99        and not a
That step eludes me (I was trying force and delay before as well - with not total success).83.100.250.79 (talk) 20:52, 26 July 2009 (UTC)[reply]
If you write (quote a) then you get a quoted symbol a, which has nothing to do with any variable named a in the environment—it's like the string "a" in other languages. (Modern Scheme also has strings, but earlier versions just had symbols doing double duty.) If you write (quasiquote a) then you get the same thing because quasiquote quotes everything that isn't wrapped in unquote. You could write (quasiquote (unquote a)), but that's the same as just a.
If you want to update a and have b reflect those changes "on the fly" then that can't be done directly—there's no way to make a data structure incorporate the current contents of a variable by reference. Variables (like a and b) point to objects (like numbers and pairs), and some objects (like pairs) can point to other objects, but objects can't point to variables. This is similar to Java, where you can only have references to heap objects, but different from C++, where you can also have pointers to variables and object fields. But you could write a function that makes the appropriate change to both a and the corresponding part of b explicitly:
         (define (change-a! new-value)
           (set! a new-value)
           (set-car! (cdr b) new-value))
-- BenRG (talk) 20:59, 26 July 2009 (UTC)[reply]
Thanks, Yes it's exactly the type of thing you describe in the second paragraph that I'm trying to do (though I read that set-car! is to be 'banished' in v.6 scheme)
Maybe I'm using the wrong tool - I'm looking for a language with strong support for nested lists (ie like lisp or scheme), but with pointers to objects as well (the easy way) - does such a thing exist?83.100.250.79 (talk) 21:10, 26 July 2009 (UTC)[reply]
But every value in Scheme is already a pointer. (It's like Python.) That's why you can do stuff like this
         (define a (car 1 2))
         (define b a)
         (set-car! a 3)
         (car b) ; evaluates to 3
--Spoon! (talk) 07:15, 27 July 2009 (UTC)[reply]
As Spoon said, if a refers to a pair and you incorporate a into b, then change the members of the pair, that change will show up in b. But you can't do that with numbers like 10 (they are immutable) and you can't replace the whole pair "in place" with a number or vice versa—you have to do two assignments to the two pointers that reference the pair in that case. People often solve this kind of indirection problem with extra levels of indirection. A common trick in Scheme is to create a pair with a dummy symbol in the car (like '*my-mutable-thing*) and the payload in the cdr. That does require extra indirection when reading, though. Even in C++ you can't indirect via a variable without an extra * when reading.
ML is a Scheme-like language (it shares the emphasis on lists and recursion) that handles mutation in a cleaner way than most other languages. It avoids all these funny rules about variables versus objects versus parts of objects, but it may not be more convenient in practice if you already understand those rules. You could also look at dataflow programming. In dataflow languages, when a changes, not only does b automatically change but also any other computation whose value depended on a. For example if you had written (define c (+ a 10)) then incrementing a would also increment c. The DrScheme system includes a dataflow extension called FrTime. But hardly anybody uses dataflow languages, so if you need the support and future-proofing that you would get from a mainstream language then you probably can't use dataflow. If you give details on what you're trying to do we could probably give better suggestions. -- BenRG (talk) 09:06, 27 July 2009 (UTC)[reply]
(edit) I'm going to have a look a FrTime, and see what it does83.100.250.79 (talk) 12:03, 27 July 2009 (UTC)[reply]
(edit) It sounds like FrTime does too much - it sounds like it re-evaluates the whole data structure when a field changes - I just want it to evaluate what is necessary for an imperative instruction.83.100.250.79 (talk) 12:08, 27 July 2009 (UTC)[reply]
Thanks, your description of dataflow programming sounds like what I was thinking about.
Basically I was just exploring the features of programming languages without any particular application in mind.
Specifically if a is a variable I would have been incorporating it into many different lists - so the scheme method listed above by BenRG wouldn't really be suitable. - I wouldn't be able to (or expect to) keep track of all the instances of a. So the equivalent of a pointer data type would have been the way to go - However I only needed the data to update on imperative resolution eg not sure if this is the same as 'dataflow'.
I was also hoping to mix functions and data in a list in a similar fashion - but noticed that if a function returns differently sized or structured lists then this could really mess up the whole thing - requiring functions to be run (with the wrong state information) just to attempt to get the size of the list. eg if a=(0 fn(x) a ) and fn(x) can return 0 or 1 or (0 1 2) or even +{0 1 2}+ ie inserted flat into the list, not nested then I can't find/think of a solution for that as yet. I could probably implement the list with pointers myself though.83.100.250.79 (talk) 11:21, 27 July 2009 (UTC)[reply]
I was just reading what Spoon! said - it looks like I didn't understand the data structure - I was expecting everything to be a pointer (as they say)- the language has to be intrinsically 'pointy' for those lists.
What I don't get is why Spoon!s example works, but when I just do (define a 10) , (define b a) , (define a 20) ; b gives 10 ie it immediately dereferences b and a, but when using a pair it does something different. Is there an exaplanation for this apart from 'that's the way it was designed' (Isn't 10 a list too, with the second field null?) 83.100.250.79 (talk) 11:31, 27 July 2009 (UTC)[reply]
10 is not a list. In C++ terms, all variables have type Object*, numbers look like
       struct Number : Object {
           const int value;  // or double or complex or ... full numeric tower
       };
pairs look like
       struct Pair : Object {
           Object* car;
           Object* cdr;
       };
and the empty list is like the null pointer. So when you write (define a 1) (define b a) (set! a 2) it's like
       Object* a = ONE;  // where ONE is a global that points to a Number with value 1
       Object* b = a;
       a = TWO;
which doesn't change b. But when you write (define a '(1 2)) (define b a) (set-car! (cdr a) 3) it's like
       Object* a = new Pair(ONE, new Pair(TWO, NULL));
       Object* b = a;
       a->cdr->car = THREE;
which leaves b->cdr->car also equal to 3. (Note that you shouldn't use define to change the value of an already-defined variable, though it's supported. You should use set! for that.) If I understand you correctly, the problem you're having would also exist in C++. If a is a pointer and you incorporate that pointer into a bunch of data structures, changing a won't change the data structures—you would have to track them all down and update them individually. -- BenRG (talk) 15:53, 27 July 2009 (UTC)[reply]
(First Note: you shouldn't use define on a variable twice in the same scope. Use set! to assign to a defined variable.) set! only changes where a pointer is pointing to. It does not affect the thing that is pointed to. So when you do (set! a 20), it just redirects the pointer to point to another number object. Whether you can modify an object pointed depends on the type of object. There is no mechanism to modify a number object (i.e. they say it is immutable). However, there is a way to modify pair objects, with set-car! and set-cdr!. That's why you can modify a pair object and be able to see the changes through another pointer that points to the same pair object. --Spoon! (talk) 19:49, 27 July 2009 (UTC)[reply]

Thanks for your responses - I've found something that almost does what I want : 

(define a 200)
(define b (lambda() a))
(b)
result 200
(define a 300)
(b)
result 300

this always evaluates to the current value of a, which is good, but I have to bracket b to get the number, if anyone can suggest a better way, please, as I'm still working out if I can utilise this method easily.83.100.250.79 (talk) 15:15, 27 July 2009 (UTC)[reply]

I was going to suggest that, but I'm not sure it's really what you want. -- BenRG (talk) 15:53, 27 July 2009 (UTC)[reply]
You shouldn't define something twice. Use (set! a 300). --Spoon! (talk) 19:44, 27 July 2009 (UTC)[reply]

Another mystyfying thing about scheme

As mentioned above I was trying things like (define a 10) , (define b a) , and (cadr (1 a 3)) - now in the first two examples it treats a as a variable, whereas in the third it seems to just think a is "a" ie text. How does it decide? And does ML (mentioned above) or another language (in the family) support a more explicit of distinguishing variables and text?

I know this is very similar to sticking beans up my nose as a hobby , but if anyone end my curiousity I would thank them. :) 83.100.250.79 (talk) 11:47, 27 July 2009 (UTC)[reply]

(cadr (1 a 3)) is an error—it attempts to call the number 1 as a function. You mean (cadr '(1 a 3)). That gives you a quoted a because quote (') quotes everything underneath it in the expression tree. define is a so-called special form (as is quote). It's magical and can't be implemented as a Scheme function. You should read a Scheme tutorial, which will explain all of these things better.
In ML everything is read-only except for refs. A ref lives on the heap and holds a value that you can get or set. Instead of a mutable variable you use a constant variable that refers to a ref on the heap. This means that every mention of a variable is a mention of its value, not a reference to its location, so you don't need a special form like set!. If you incorporate the variable's value into a data structure then the data structure refers to the same ref and setting it will affect the data structure too. You could get the same effect in Scheme by defining
        (define (make-ref val) (cons '*ref* val))
        (define ref-get cdr)
        (define ref-set! set-cdr!)
and then never using any mutation functions other than ref-set!. -- BenRG (talk) 15:53, 27 July 2009 (UTC)[reply]
Thanks, (yes I missed the ' ) - I think my exectations may have been wrong - I read that scheme/lisp stores program/data in the same form and that a program was a list too - from this I inferred (wrongly) that lists created by the program could contain executable programs as well ('out of the box' so to speak).
I have been reading scheme tutorials (possibly not very good ones - they didn't explain that '(+ 1 2) destroys all type formatting and renders function names as text)- I suppose the reason they didn't have the answer was that what I was looking for didn't exist - oh well!. So there's not a way to force an evaluation on a list eg
(try-this-list-as-a-program '(+ 1 2) )


83.100.250.79 (talk) 16:29, 27 July 2009 (UTC)[reply]

because + has been convereted forever to a char, and can't be got back into a proceedure type. —Preceding unsigned comment added by 83.100.250.79 (talk) 17:16, 27 July 2009 (UTC)[reply]
There is eval in R5RS Scheme:
    (eval '(+ 1 2))
:-) --Spoon! (talk) 19:37, 27 July 2009 (UTC)[reply]
Cool. (I did try eval on the off chance - but it didn't quite work..)
I'm using "DrScheme" R5RS and eval doesn't work - gives the curious error message "procedure meval: expects 2 arguments, given 1: (+ 1 2)" (yes it spells eval wrong as well), must be a bug. Curiously in MrEd (same distribution) eval works as planned. Anyone familiar with PLT Scheme and know what's going on? 83.100.250.79 (talk) 20:21, 27 July 2009 (UTC)[reply]
Here's the spec. eval takes two arguments, an expression and an environment. There's no standard way to get the current environment (it would require a special form because of lexical scoping). Supposing a (current-environment) special form exists in your Scheme, (eval 'a (current-environment)) does the same thing as a but is very inefficient. Storing an expression in a data structure and then evaling it does the same thing as putting it in a (lambda () ...) and then calling it, except that it's much slower, less convenient to call, and violates lexical scoping (because it will see the variables at the call point instead of the variables at the definition point). There's no reason to use it. Code and data are not the same in Scheme, they just look alike because they have the same syntax (s-expressions). -- BenRG (talk) 08:58, 28 July 2009 (UTC)[reply]
Yes thanks, I got the feeling it was the same as going through the command line interpreter ie it has to convert what is effectively an ascii string to whatever code scheme uses. I wan't to avoid that.
I think I'm getting it to do what I want now :eg
(define a (lambda () '(1 2 3)))
(define b (lambda () (cons 4 (cons (a) 6))))
Which makes the 'a' in function b act like a pointer to the function 'a', and 'b' changes with a. this is the reason I was originally interested - because I got the impression scheme/lisp could do thinks like this easily - thank god it does :)
I'm just trying to work out the difference between '(4 (a) 6) and (cons 4 (cons (a) '(6) )corrected once - initially I got the impression that the structures created by both were the same ,with (list 1 2 3 etc) just being a shorthand avoiding doing a lot of cons.
Also does anyone know what I type in for 'null' - it rejects null , nil, ()
I can't find it in the manual except what seems to be a suggestion that typing "null" should work found it '() 83.100.250.79 (talk) 10:45, 28 July 2009 (UTC)[reply]
I'm glad you found something that works. Writing (define a (lambda () '(1 2 3))) and (a) is slightly different from writing (define a '(1 2 3)) and a because the former conses together a new list every time you call it, which matters if you use set-cdr! and the like—but maybe you don't need those any more. Everything in '(4 (a) 6) is quoted, including the (a), whereas in (cons 4 (cons (a) '(6))) the (a) is unquoted so it's a function call. The 4 is also unquoted but it doesn't matter because it evaluates to itself. -- BenRG (talk) 22:41, 28 July 2009 (UTC)[reply]
Resolved

OK thanks for your help , and your patience. I think I can call this resolved, the engine starts, and I've stopped putting sand in the tank unless somebody notices that I'm doing things the wrong way, or knows a more sophisticated solution.. In which case please say. Thanks again.

This isn't so much an answer as a further question, but nonetheless: does Scheme really not have symbol-value or any equivalent? I guess that it sort of makes sense, since it has only lexical scoping and no use of a appears lexically in (symbol-value 'a). But if eval exists (even if it's crippled by the lack of a standard current-environment special form), it seems silly not to also provide this simplest part of what it does (resolve symbols into variables). --Tardis (talk) 21:49, 28 July 2009 (UTC)[reply]
Scheme symbols (unlike Common Lisp symbols) don't have values. They're just like C identifiers. All variable references are lexical and hence are supposed to be unaffected by alpha renaming. You could write a value-at-top-level that used eval, but it would be a weird thing to standardize because it's not something you really want to encourage. Lexical scoping and eval interact badly. Aside from the theoretical issue (alpha renaming), you have to maintain a bunch of metadata at runtime that wouldn't otherwise be necessary and you have to inhibit various compiler optimizations because you can't predict at compile time what variables will be read or written by the eval. It's basically the same problem as doing it in C. I'm somewhat surprised they included eval at all. -- BenRG (talk) 22:41, 28 July 2009 (UTC)[reply]

How can I extract individual images from video-slideshow?

I have a video-slideshow created by Photo Story 3 using the Windows Media Video 9.1 Image v2 codec. How can I extract the static images from this file? --Me (talk) 20:01, 26 July 2009 (UTC)[reply]

Elevator logic control

Hi there, I'm in the process of creating an app/game/sim/whatever you want to call it that emulates a lift (elevator). I've got the thing working pretty well but am stumped at getting the logic right for handling calls. (Originally asked this on the science desk but this is probably a better place to ask it.)

At the moment, there are two objects: DRUp and DRDown that both contain a variable which can be set to 0 or 1 (0=off, 1=on), this simulates a pair of switches that control the direction. The lift operates a 'mechanical' floor selector (a moving object that triggers events when it touches other objects) that makes contact with various switches to tell the lift where abouts in the shaft it is. When the top floor and bottom floor switches are triggered, it toggles the direction switches so if it's at the top floor then DRUp=0 and DRDown=1, because the lift cannot go up from the top floor! The ground floor switch does the opposite.

This works fine for going in the same direction, however if the lift car is on the ground floor and I am on the second floor and want to go to the ground floor, the lift goes all the way to the top, reverses direction and then stops at the second floor. I need a way of resetting the direction switches from other floors but ONLY if there are no further calls in the original direction.

Example: Lift on ground floor Call from 2nd floor Lift goes UP to second floor Are there any more calls going UP? If yes, continue up, if no, reverse direction.

I can probably do it a long-winded way by setting up a long and protracted if statement along the lines of:

If Floor=1 and LR2Up and LR3Up and CR2 and CR3 and CR4 = 0 then DRUp=0 and DRDown=1 (LR being landing call switches and CR being lift car call switches)

However I'm sure there must be a simpler way of doing it (probably something to do with the floor selector). I can't see how old-fashioned lifts with relay logic could evaluate complex if statements. I think from looking at old and very complex documents about electromechanical lift controllers, the floor selector has three parts on top of each other that tell it which way to go but not sure).

Anyway, if you're interested, I've put the project so far online: http://www.arthurflowers.co.uk/games/Lift2_1.exe , any comments would be good.

Thanks in advance for any information. GaryReggae (talk) 21:44, 26 July 2009 (UTC) —Preceding unsigned comment added by GaryReggae (talk • contribs)

May I suggest that you re-ask this question on the computing ref desk - you'll get a much better answer there. SteveBaker (talk) 21:55, 26 July 2009 (UTC)[reply]
It was not clear to me whether your lift has a single call button at each floor, or two buttons for a user to call to go up or down. There may be security problems about your link to an executable. Consider showing pseudocode instead. Cuddlyable3 (talk) 22:20, 26 July 2009 (UTC)[reply]
Thanks - I have posted this on the Computing desk too. I only posted it here in the hope that somebody that knows about electronics and engineering might know how these things work in the real world. I have been looking on Google patents about old lift controllers and it seems that the floor selector has three parts that control the direction but it's all incredibly technical and goes into too much detail.
The lift has two buttons on each floor, each one activates either an up call request switch (LRUp or a down call request switch (LRDown). Buttons pressed in the lift car itself activate a third switch for each floor (CR). At the moment, the lift will answer all the calls going down then all the calls going up but as I said, the lift currently travels to the top and bottom floors to change direction, so if I were to only want to go between two of the middle floors, I would have to go all the way and then back.
I don't know how to do pseudocode but I will try blockquoting the link:

http://www.arthurflowers.co.uk/games/Lift2_1.exe

GaryReggae (talk) 22:29, 26 July 2009 (UTC)[reply]
There are many articles that contain examples of pseudocode. Loading executables from the Internet is forbidden in many computer environments e.g. school networks, because of the potential for virus attack. Cuddlyable3 (talk) 22:58, 26 July 2009 (UTC)[reply]
--- end of answers from Science Desk ---


minor point (Did you realise that by directly linking to the file you have allowed users to circumvent your draconian user aggreement? eg http://www.arthurflowers.co.uk/ ?) —Preceding unsigned comment added by 83.100.250.79 (talk) 22:55, 26 July 2009 (UTC)[reply]
What language? (may help in the answers)
Another thing I have to ask is "can there be multiple people requesting the lift" - it's a lot simple if only one person uses the lift at once.
Basically don't you need two variables "LiftFloorRequest" and "LiftFloorRequestDestination" - first the lift goes to "LiftFloorRequest", then it can contine (or change direction) to go to "LiftFloorRequestDestination". You could add an additional flag for "LiftMode" - which would be either "seeking customer" or "delivering customer" which might help keep things clear.
(If more than one person is using the lift then I think real world practice is for the lift to go up to the highest request, and down to the lowest request - ie when more than one button is pressed the lift reverts to the mode you already have - ie straight up and then down.)
Also it's probably more use if you can link to the program code, rather than the program - otherwise we won't really know how you are doing it.)83.100.250.79 (talk) 22:36, 26 July 2009 (UTC)[reply]
In terms of the actual electrics, rather than a simulation - I'd guess that there would have to be a wire for each level if you want to go to the highest selected level rather than the top - though it's possible to do it with only a couple of wires. I'm no lift expert - it's not clear if you're trying to simulated the original mechanism or just making an lift program that works.
(Actually I think I can describe a very simple relay circuit for what you are describing - which would convert into two program variables - the self explanatory "HighestButtonPressed", and "LowestButtonPressed" - it's probably clear from those words that all you need to do is work out the two values, and let the lift oscillate between the two. (I imagine there are many implementations)83.100.250.79 (talk) 22:42, 26 July 2009 (UTC)[reply]
Yeah, I'm trying to simulate the original mechanism as far as is possible. There is only one person calling the lift at any time. I can't put the code in as I have built this thing using 'GameMaker', a GUI that allows you to create games. You can use variables, as indeed I have but each 'object' has its own set of 'events', such as MouseClick and Step (runs the same procedure constantly). I have an object that controls the motion of the lift car - if there are no calls then it exits the event, if there are calls then it moves the lift car in whichever direction is specified by the direction switches DRUp and DRDown. The DR switches are toggled when the 'mechanical' floor selector touches the ground or top floor switches.
Here is a screenshot: http://img188.imageshack.us/i/atflift2.jpg/
With regard to the draconian user agreement, yeah, I put it there out of sarcasm after I got in trouble at work for posting technical stuff on that website but it was nothing to do with them really.

GaryReggae (talk) 22:56, 26 July 2009 (UTC)[reply]

This doesn't address your specific issue, but you might be interested in looking at SimTower. This game evolved from an earlier elevator simulator and ended up being fairly commercially successful. Nimur (talk) 23:04, 26 July 2009 (UTC)[reply]
I'm not sure that I can help you much more, but I think I can explain how the relays simulate the logic if you need that (you mentioned above that you didn't see the connection) - if there are two wires coming from the top, one 'power', and one 'signal' - then pressing the button on a floor will connect power to signal by activating a relay. By doing this power is routed to the signal wire (going down) - thus the power wire below this floor is now not connected... The relays on each floor have to be set up so that the signal cannot go upwards at the point were power is routed to signal. (probably a double throw relay) this has 3 effects:
  • thus the signal wire is only live below the highest floor on which a button has been pressed.
  • power wire is disconnected on floors below. (therefor pressing the button does nothing)
  • pressing a button higher up still works

(If the power is off then the switching relays need to reset themselves.)

Combine this with the same mechanism going upwards instead of downwards (another 2 wires plus 'ground')
The lift only runs where both the signal wires are live - additionally losing one of the signal wire connection means the lift needs to change direction - this can be acchieved with relays too. ie connect the two signal wire feeds to another relay - if one is absent the relay will switch (in one of 2 directiosn)- which in turn can be used to switch the motor power.
Obviously getting the lift to stop exactly at the floor makes this more difficult.
I think it would be quite possible to emulated this in your program if you haven't already - ie you could have close up images of the relays switching, or mabybe even colour the wires where they are live.83.100.250.79 (talk) 23:21, 26 July 2009 (UTC)[reply]
By the way I think the technical term is Interlocking - but all that article is about trains and not lifts - though a lot of the principles are the same.83.100.250.79 (talk) 23:24, 26 July 2009 (UTC)[reply]
Elevator Logic

The number of floors in the building is Nf.
The following are independent on/off states. Each could be a latching relay (relay controller), a set/reset latch (logic
controller with MSI chips or FPGA), 

or one-bit flags in memory (µP controller).

- For each floor i = [1...Nf] there are 3 state bits:
  Cdi = Call to descend
  Cai = Call to ascend
  Di  = Directed to floor
  Cdi and Cai are set by pushbutton call switches at each floor. Cdi and Cai illuminate their respective call button so
the caller gets immediate confirmation.
  Di are set by pushbuttons inside the elevator and illuminate their respective buttons so riders get immediate confirmation.
  
- For the elevator there are state bits:
  Kdi = Commit to descend from floor #i
  Kai = Commit to ascend from floor #i
  (Kdi AND Cdi) and (Kai AND Cai) are AND functions that illuminate arrows at the respective elevator doors. These give
further confirmation to a caller that s/he will soon be served, and they show which of Cdi/Cai will be answered first
when both call buttons have been pressed. A "ping" sound is given at the floor when either arrow lights.

The elevator logic monitors the location of the elevator f = [1...Nf]. This can be done in various ways such as by a rotary
optical encoder in the lifting gear, or interlocking microswitches at each floor. It could be done using a momentary
contact switch at each floor thus: as the elevator touches each switch the controller increments or decrements a floor
counter, depending on whether the elevator is ascending or descending. Floor #1 has an extra contact switch that keeps
the floor counter synchronised to the actual floor numbers. Number f is displayed to riders inside the elevator.

Initialisation at switch on and after a power break:
 All (5 x Nf) - 2* state bits reset.
 Bring elevator to f = 1 (ground floor) to synchronise floor counter.
 Self test routine (in µP) may include testing all lamps.


The elevator logic executes the following.
-----------------------------------------
SCAN UP CALLS
Pa = 0  pending ascend flag 
for i = f to Nf
 Kai = Cai OR Di
 if Kai=1 and Pa=0 then fd = i  destination floor 
 Pa = 1
next i
if Pa=0 goto SCAN DOWN CALLS

while f<fd raise elevator
(At floor fd) Open doors, Caf = 0, Kaf = 0, Df = 0
(After delay 5 seconds) Close doors. If door is blocked, open and repeat.

goto SCAN UP CALLS

SCAN DOWN CALLS
Pd = 0  pending descend flag
for i = f to 1 step -1
 Kdi = Cdi OR Di
 if Kdi=1 and Pd=0 then fd = i  destination floor
 Pd = 1
next i
if Pd=0 goto SCAN UP CALLS

while f>fd raise elevator
(At floor fd) Open doors, Caf = 0, Kaf = 0, Df = 0
(After delay 5 seconds) Close doors. If door is blocked, open and repeat.

goto SCAN DOWN CALLS
-----------------------------------------

Notes on this simple elevator implementation: 
1. When no one uses the elevator the controller alternates between SCAN UP CALLS and SCAN DOWN CALLS. That is innocous
for a µP controller but would be unwelcome activity in a relay controller.
2. Calls are not served well while the elevator is in motion. It is possible for the elevator to proceed past a floor
if a call to that floor was made after the elevator starts. That will distress a rider who changes their mind during
travel.
3. No provision was made for soft acceleration/deceleration so the elevator speed is limited.

Possible improvements which are more suitable for tall buildings:
Re. 1. When Pa = Pd = 0 the elevator could be sent to an optimum rest floor, such as ground floor or a mid floor.
Re. 2. Response to rider controls could be improved by scanning Di's more often than only when the elevator stops.
Re. 3. Higher speed without abrupt starts/stops is possible if full speed/stop is reached only after travelling one floor.
However for that strategy one cannot respond while the elevator is in motion to a new Di (in 2. above) nor commit to a new
Cdi/Cai where i is closer than f +/- 1. Travel from a floor to an adjacent floor can only reach half the maximum speed.

Overload, Fast Mode
The elevator car should have a load sensor.
- EXCESS load causes the doors to stay open, prevents elevator movement and (preferably) shows a warning to occupants.
The following improvements to load sensing are possible.
- FULL load corresponds to maximum number of adult occupants. Ignore floor calls and obey only occupant directions Di.
This avoids serving floor calls with a full elevator that the caller cannot enter.
- EMPTY load corresponds to less than the weight of a child. Move elevator at maximum speed with abrupt start and stop.

*On floor #1 there is no Cd1 button nor down arrow. On floor Nf there is no CaNf button nor up arrow.

Cuddlyable3 (talk) 21:04, 27 July 2009 (UTC)[reply]

July 27

AI database

10 or 15 years ago (I think), there was a project to get volunteers to input common knowledge into a database for an AI program to use (things like apple ISA edible fruit). Does anybody know what happened to it? Clarityfiend (talk) 04:12, 27 July 2009 (UTC)[reply]

It sounds like you're talking about a Commonsense knowledge base. There's several famous ones listed on that page. The one closest to your description is Open Mind Common Sense, I think. Indeterminate (talk) 05:07, 27 July 2009 (UTC)[reply]
I think it was Cyc; the name rings a bell. Thanks. Clarityfiend (talk) 06:11, 27 July 2009 (UTC)[reply]

Python "for x in y" operator overload

When I use if x in y: (expecting a boolean to be returned), the real operator being called is __contains__ (so that x.__contains__(y) is the same as y in x). But apparently, when I use for x in y: it's something different. It's not even mentioned in help(list). Here's some sample code I wrought up: 

class x:
    def __init__(self):
        self.data = [1,2,3,4,6,5,7]
    def __contains__(self,con):
        return con in self.data

## Now, testing it:

if 4 in d:
    print(4)    ## good - it returns 4
if 26 in d:
    print(4)    ## good - it doesn't return 4
for x in d:
    print(x)    ## bad - it gives "TypeError: 'x' object is not iterable"

Anybody know what the underlying operator is? Thanks, [flaminglawyer] 04:24, 27 July 2009 (UTC)[reply]

You're looking for the iterator protocol. For example:
class Uppercaser(object):
    def __init__(self, strings):
        self._strings = strings

    def __iter__(self):
        for string in self._strings:
            yield string.upper()
In usage:
>>> for s in Uppercaser(['Foo', 'bAr', 'baZ']):
...     print(s)
... 
FOO
BAR
BAZ
You can easily implement __iter__ using a generator. You can also implement __getitem__ and __len__ instead, but iterators are generally a nicer solution. 24.76.174.152 (talk) 05:18, 27 July 2009 (UTC)[reply]
Wow. Your explanation is really straigtforward... But the docs page... I'll have to look into this new "iterator" thing. Thanks :) [flaminglawyer] 05:46, 27 July 2009 (UTC)[reply]

Download albums from Shutterfly?

Hi. My friend has several albums on Shutterfly of an activity that I was in too, and I want to download the pictures onto my computer (hi resolution if possible). I know Shutterfly probably doesn't want you to do this (as they won't make ad money if you don't use their site to access the pictures), but I was wondering if someone has made a free tool to do it. I clicked on one image and it gave me an option to download that image after I sign in (I don't know if this is a limited thing or if it will work for every picture). However, there doesn't seem to be a way to download the entire album. The albums have like 700 pictures in them so manually going through each picture is not feasible. Thanks, --76.91.63.71 (talk) 10:25, 27 July 2009 (UTC)[reply]

Your friend uploaded the images to shutterfly so why not get the images directly from your friend? If the images are not huge (<6MB), each album should easily fit on one DVD-R. Astronaut (talk) 23:31, 27 July 2009 (UTC)[reply]

Bellinis Bikini

I can't get any further, please help me complete the fucking game .. It's soo hard!! (: I can't find any light, so I can go into the cave, and how do we move on? Please help we are desperate!!!!

... or you could try posting this on the entertainment desk. They're generally better with video games. [flaminglawyer] 22:44, 27 July 2009 (UTC)[reply]

What is window vista ultimate??

can anyone give me a description and the general purpose of the window vista ultimate?? i will wait for your reply.... wish to see your reply soon... thank you ^^ —Preceding unsigned comment added by Bebezaii (talk • contribs) 13:49, 27 July 2009 (UTC)[reply]

See Windows Vista editions#Windows Vista Ultimate. PrimeHunter (talk) 13:53, 27 July 2009 (UTC)[reply]
(e/c) See our article on Windows Vista editions. Basically it's Home Premium (the best version for regular home users) and Enterprise (for large businesses) combined with a few extra features added on. It requires a really really high-end computer if I remember correctly. If you're thinking of buying it, then you should probably wait for Windows 7 Ultimate to be released this October. Xenon54 (talk) 13:55, 27 July 2009 (UTC)[reply]
No, I can't think of any features in Ultimate that require "a really really high-end computer". Windows Aero is the Vista component (optional to use) which has the highest system requirements, and it isn't specific to Ultimate. Tempshill (talk) 14:53, 27 July 2009 (UTC)[reply]
The answers can be got 'from the horses mouth' as well - http://www.microsoft.com/windows/windows-vista/compare-editions/default.aspx - to summarise 'ultimate' is the business ready version of vista with the media features of the home premium version.83.100.250.79 (talk) 15:19, 27 July 2009 (UTC)[reply]

Bitdefender Rescue cd

How do I use this file BitDefenderRescueCD_v2.0.0_27_07_2009.iso.md5, MD5 check program accept it. Also how should I verify the checksum of BitDefenderRescueCD_v2.0.0_27_07_2009.iso. yousaf465'

I got the checksum of download file as "1813A52837CC06E7C2EB25A416FBE84E". yousaf465'
The purpose of the checksum is to make sure that the large .iso file downloaded with no errors. You should take the md5 of the ISO file. Then, compare it to the expected MD5 in the the small text-file. If the computed hash matches the pre-computed hash, then we can say with a high degree of certainty that you have the correct .iso file. This is an effective way to assuage paranoia about download errors or intentionally modified binary files, but it is not a required part of the process to burn a CD. Nimur (talk) 15:33, 27 July 2009 (UTC)[reply]
BitDefenderRescueCD_v2.0.0_27_07_2009.iso.md5 is not a text file, how could i check md5, the above Md5 checkesum is for BitDefenderRescueCD_v2.0.0_27_07_2009.iso.yousaf465'
 Done I open the md5 file with notepad it gave "1813a52837cc06e7c2eb25a416fbe84e BitDefenderRescueCD_v2.0.0_22_07_2009.iso

" I think this file is correct. Will check with a md5checksum program.yousaf465'

seeking identification of an icon

Does anyone know what program this icon is from?—msh210℠ 17:03, 27 July 2009 (UTC)[reply]

I don't know but maybe if you crop it you can run it through tineye-- penubag  (talk) 18:31, 27 July 2009 (UTC)[reply]
What happens if you hover the mouse over it, or click on it (left or right)? Astronaut (talk) 23:24, 27 July 2009 (UTC)[reply]
No, the image is too small. You could try interpolating/scaling it but I don't know if that will help, I suspect TinEye just doesn't do that sort of thing Nil Einne (talk) 23:50, 27 July 2009 (UTC)[reply]

Windows/Mac comparison

Are there any advantages of Macs over Windows and vice versa (From a general perspective)? Chevymontecarlo (talk) 17:24, 27 July 2009 (UTC)[reply]

http://www.xvsxp.com/finalscore/ 87.113.158.164 (talk) 17:44, 27 July 2009 (UTC)[reply]
Something I found lacking in this is that while where was a "games" category, it only talked about games that game with the OS (minesweeper/solitaire/ect.), and it didn't mention the fact that FAR more commercial retail games are available on windows, compared to Mac. Chris M. (talk)
It depends entirely on the user. They are nothing more than different operating systems. It is like asking if a motorcycle is better than a van. Both are transportation vehicles, but they meet different needs for the user. If you can state what you plan to do with your computer, there is a possibility that one may meet your needs better than the other. -- kainaw™ 17:59, 27 July 2009 (UTC)[reply]

Game bot/ai

My school will have a programming competition. The idea is to make an algorithm to control pieces of a board game. The game takes place on a MxN grid. It starts by placing K black and white pieces on random positions on the board. On every turn a piece is randomly selected and the algorithm gets to move it. The piece can move one step to one of the 4 major directions, possibly eating an enemy piece, but not off the grid or onto a friend piece. The data the algorithm gets for deciding where to move the piece is what the piece "sees" in the four major directions and the distance to it. If the piece sees a friend piece (instead of the grid edge or an enemy piece), it also sees the "color" of that piece, a 4 byte number (pieces can't see their own color and there's no other memory that lasts longer than a turn). The piece can also set its own color when it gets a turn. A player wins the game if all of his pieces are "connected visually", ie any piece can see all other pieces directly or through other piece that sees other piece ... that sees the piece. (Please forgive my English).

I'm a bit stuck with this. The only thing I can think of is trying to command the pieces towards the center of the board. I don't know any other similar games either. All kinds of help are welcome. --91.145.73.220 (talk) 22:19, 27 July 2009 (UTC)[reply]

I'm a bit confused about "The piece can also set its own color when it gets a turn" - does this mean a piece can turn into an enemy piece after it moves?
Also does the algothym get the absolute position of friendly pieces each turn eg (x,y) position
Also a bit confused about "if a piece sees a friend piece" - but then you say "pieces can't see their own colour": Are friend pieces not all either black or white?
Also does player A get the 'views' of player B's pieces, or just their own?
Also what does the "4 byte number" you mention contain? (It sounds like a difficult puzzle by the way - you might want to alert the maths desk to this question)83.100.250.79 (talk) 22:39, 27 July 2009 (UTC)[reply]
On the "4 byte number" thing, that means a number (in binary) that has 4 digits (bytes), meaning any number between 0 and 15 (0000 being 0 and 1111 being 15). [flaminglawyer] 22:52, 27 July 2009 (UTC)[reply]
... and I don't think the maths desk would help on this one, it's purely programming. [flaminglawyer] 22:54, 27 July 2009 (UTC)[reply]

Sorry about the confusion.

  1. It cannot turn into an enemy piece. Every turn one (random) piece can move and (must) set its color. Only friend pieces see the color, enemies are seen just as "enemies".
  2. The algorithm gets no info but what it sees.
  3. Oops, no wonder if this confuses. I meant to say player A's pieces are white and player B's black. Then pieces have a color that is the 4 byte number and only visible to friend pieces. It makes sense if you want to believe into it.
  4. I assume you mean the "visual connection" thing, no, enemy pieces cut the connection.
  5. The 4 byte number contains the color, the algorithm must set it every times it moves the piece. Initially the color is 0.

--91.145.73.220 (talk) 23:03, 27 July 2009 (UTC)[reply]

Good that's clear - actually for 4 I meant : does Player A get a list of what Player B's pieces can see - but I understand now - if a player's piece can't see another piece of the same (black or white) colour as itself it's effectively blind. 83.100.250.79 (talk) 23:31, 27 July 2009 (UTC)[reply]
Also 4bytes is 32bits - Can I make the assumption that N+M<=32 ? (ie a smallish board)83.100.250.79 (talk) 23:33, 27 July 2009 (UTC)[reply]
That's left somewhat unspecified, but there should be small cases too. Also just to make sure, even if a piece doesn't see a friend in some direction it still knows whether there's an enemy or the grid edge and how far it is from it. --91.145.73.220 (talk) 00:03, 28 July 2009 (UTC)[reply]
Huh. Well, one strategy you might think about is that if a piece can see a friendly piece, it probably shouldn't move in a perpendicular direction (so it loses sight of its friend). If it sees a friend to the North, it could move north or south until it sees another friend to the east or west, then stop. If it can't see a friend, it could go any direction, I guess. The "color" sounds like it's just supposed to be used as a state variable, so that when a piece sees a friend, it knows how many friends that friend can see. Or something like that. Anyway, sounds like fun, good luck. Indeterminate (talk) 02:47, 28 July 2009 (UTC)[reply]
One useful thing I can think of is that the computer can be programmed to derive the relative positions of connected (viewed pieces), there may be more than one set of view connected pieces (and it may not be immediately certain which pieces can see each other eg if 2 pieces can see a piece 4North, and 2 pieces can see a pieces 4 south there's a 50/50 chance of guessing which piece is actually seeing the other - I imagine the colour seetting function could help here after a couple of moves)
If you construct sets of connected pieces it should be obvious that each set requires a 'sub-board' of at certain size, that can be derived from the data - this sub board size can be used to derive a range of absolute positions for those pieces. A second set of view connected pieces can be used to reduce the number of possibilities for the absolute position of the first set (ie certain combinations are impossible, or connect the two sets)
Using this derived data you can get a expectation (probability) of a given square being viewable or not. Additionally you can get an expectation of where each view-not connected piece might be using the same data set.
Using these two values you can make moves giving the highest expectation of moving towards or into a viewable square. This doesn't guarantee a win, but should increase the chances of winning over many random games..
Apart from using the colour values to help remove uncertainty as to which sets are connected as described above, I haven't really though of a use for them, except to keep track of how much a pieces has moved from it's starting position - which can be useful...
Some of the concepts seem similar to a game of Battleship (game) - maybe there have been some studies of winning strategies for that game which you could find out about?? (and modify)
It's clear to me that the method I've decribed doesn't do 10% of what could be done, though I haven't got a clue what other methods could be used.
In the absence of anything else I'd suggest moving the pieces towards an edge along the shorter length :) 83.100.250.79 (talk) 13:08, 28 July 2009 (UTC)[reply]
By the way one issue with the method above is that it's a brute force method, and the number of combinations gets massive rapidly as the board size increases.. It will probably be out of the range of a desktop computer if the board is say 32x32 with 10 pieces each.83.100.250.79 (talk) 13:21, 28 July 2009 (UTC)[reply]
Also it might help if number of pieces is always less than 32 - any clues?83.100.250.79 (talk) 13:48, 28 July 2009 (UTC)[reply]
There is no "history" any piece can see. Unless...set it up so the number of the colour indicates how many pieces that piece can see. Because you win by having the bigger network of pieces, the piece whose turn it is should move to where it will increase the total "visibles" available to it. So if North-South has a higher count than East-West, it should move NS, in the hope of finding a higher-scoring EW line. If the visible EW is say more than 50% of the possible high score, perhaps it should pass its turn to a brother piece. Giving preference to eating an enemy piece is fraught with danger...if the enemy has his own kind as neighbours, the eating piece might become the victim in the next turn._ KoolerStill (talk) 14:54, 28 July 2009 (UTC)[reply]

Colour schemes in GUIs

I thought this would be easy to find, but no! it's not. Could anyone point me in the direction of research papers/articles on good (and perhaps not-so-good) colour schemes in GUIs or similar? There are a couple of names in my head who did research in this area but their actual names escape me now. Thanks in advance. x42bn6 Talk Mess 22:37, 27 July 2009 (UTC)[reply]

I don't know of anything specifically (or at all), but I can point you to Google Scholar, which (basically) searches a bunch of papers/articles to find what you want. [flaminglawyer] 22:48, 27 July 2009 (UTC)[reply]
This page mentions "Murchs Rules" [13]
Does that ring a bell? There are some other references on the page too.83.100.250.79 (talk) 22:52, 27 July 2009 (UTC)[reply]
Thanks, I think that was one of the names. I'll keep looking around. x42bn6 Talk Mess 23:17, 27 July 2009 (UTC)[reply]
The importance of consistency in user interfaces has been documented in many human-computer interaction research areas. Don't re-use the same color for different conceptual ideas - it is a source of subtle confusion. Nimur (talk) 23:30, 27 July 2009 (UTC)[reply]

July 28

downloading all torrents with wget

So I want to download all of the torrents on The Pirate Bay with wget. I thought this would be a good command:

wget -N -r -l inf --no-remove-listing -A torrent http://thepiratebay.org

also equivalent to

wget -m -A torrent http://thepiratebay.org

It only gives me this:

--18:03:43-- http://thepiratebay.org/index.html => `thepiratebay.org/index.html' Resolving thepiratebay.org... 192.121.86.15 Connecting to thepiratebay.org|192.121.86.15|:80... connected. HTTP request sent, awaiting response... 404 Not Found 18:03:44 ERROR 404: Not Found.

Removing thepiratebay.org/index.html since it should be rejected. unlink: No such file or directory

FINISHED --18:03:44-- Downloaded: 0 bytes in 0 files

Is this because TPB has blocked wget? Why won't it work? :( Mac Davis (talk) 00:43, 28 July 2009 (UTC)[reply]

TPB, like many sites written using PHP, uses index.php, not index.html. Indeterminate (talk) 01:14, 28 July 2009 (UTC)[reply]
Are you sure this is a good idea? If I'm reading the front page correctly, there are over 2 million torrents on the site. Exxolon (talk) 01:22, 28 July 2009 (UTC)[reply]
Yes, after your HDD gets overfilled, catches on fire, and a skull-and-crossbones flashes on your screen, come tell us how it went. ;) [flaminglawyer] 01:34, 28 July 2009 (UTC)[reply]
Further... wget will not download the data. It will download the torrent file - a file which you use with a torrent program to download the data. In other words, you will end up with millions of torrent files. By the time you attempt to use them, most will be stale and worthless. -- kainaw™ 01:55, 28 July 2009 (UTC)[reply]
He probably wishes to make a competing tracker site and jump-start it by ripping TPB's entire database. APL (talk) 15:37, 28 July 2009 (UTC)[reply]

Problems with MSN Audio

I live in Toronto, and used to have video calls with relatives in China with MSN Messenger. Despite the long distance involved, it worked perfectly. However, for apparently no reason whatsoever, the audio stopped getting through two weeks ago; MSN Messenger would take one-second recordings from my relatives' computer and repeat them over and over again. If they say the sentence "It's a lovely day today", I might hear the word "it" repeated several times before hearing the same thing with "today".

Both me and my relatives are able to have video calls with friends in the same city with no problem. Neither of us use Windows XP (which is known to cause choppy audio), and as far as I can tell, there have no changes in the speed of our Internet connection. What might be the problem? --Bowlhover (talk) 03:04, 28 July 2009 (UTC)[reply]

Problem with CLASSPATH

Resolved

Hello! I've been working on a Java swing program with NetBeans that uses several ImageIcons that I have created with the NetBeans GUI builder. When I run the program in NetBeans, it works fine, but now I want to distribute it as a .jar file and am having a lot of trouble. I get a java.lang.ExceptionInInitializerError-->NullPointerException that, according to the stacktrace, seems to be caused by not being able to load the files for the ImageIcons. Here's how my project looks: 

My NetBeans project/.jar file:
|-->Map (package with all my .class files)
|-->images (package with half of my files for ImageIcons)
|-->photos (package with the other half)

Can I fix this problem by altering the MANIFEST file? What exactly do I put for the argument after the "class-path:"? Is there a better way to do this? I'm going to distribute it to people who have little experience with computing, so I need the execution of the program for them to be as simple as a double-click. I'll appreciate any help or suggestions. Thank you!--el Aprel (facta-facienda) 03:35, 28 July 2009 (UTC)[reply]

Boy, do I feel stupid! After several hours wasted, I fixed my own problem, and it turns out that I had saved my images as .JPG files, not .jpg files, which doesn't mean anything different to any computer running any OS...but does make a difference for the JVM. Java's case sensitivity applies even to its getResource() method. It hadn't occurred to me that that could have been causing the problem because I thought I had done file I/O and that wasn't case sensitive. Guess the java.io classes call the OS to do the work and get the file, and the OS isn't case sensitive, but Java must handle getting its own resource and uphold case sensitivity. Learn something every day.... I still don't understand why it ran fine in NetBeans even with the wrong case, but at this point, I'm just happy I got the .jar to work.--el Aprel (facta-facienda) 22:38, 28 July 2009 (UTC)[reply]
It is certainly possible to put the images in the JAR file. JAR files are intended for both .class binary and resource (e.g. images, audio) distribution. Can you printStackTrace() on the error, and post the results? (That might actually hint you in the right direction anyway). Probably the issue stems from some relative path issue; also look at Sun's Java guide for accessing resources in JAR files. Nimur (talk) 22:37, 28 July 2009 (UTC)[reply]
Specifically - here's the Retrieving Resources from JAR files guide. Nimur (talk) 22:39, 28 July 2009 (UTC)[reply]
Some operating systems do use case-sensitive file names. NetBeans uses the operating system's file handler (because the development SDK is not running entirely inside the JVM), but the deployed program by necessity must use the Java JAR resource manager (because it must do so from the bytecode and be platform portable). Case-sensitive filenames (especially extensions) are a common source of "lost" resources and mysterious "it worked over there five seconds ago!" bugs. Nimur (talk) 16:43, 29 July 2009 (UTC)[reply]

call related material required

hi,

i need MO/MT call related information as i am preparing for interview.please help me in this regard. —Preceding unsigned comment added by Sudcool2009 (talk • contribs) 07:15, 28 July 2009 (UTC)[reply]

java programming

a program implementing an atm to help security of an institution sign students laptops into and out of the school compound —Preceding unsigned comment added by Qcush (talk • contribs) 12:21, 28 July 2009 (UTC)[reply]

When would you like that done by? --Sean 13:36, 28 July 2009 (UTC)[reply]
How could an ATM sign laptops out of a compound? What exactly is your question? Do you need help finding such a program, or designing such a program? Nimur (talk) 22:15, 28 July 2009 (UTC)[reply]
This program will "sign students laptops into and out of the school compound". I hope this is what you wanted. « Aaron Rotenberg « Talk « 16:03, 29 July 2009 (UTC)[reply]
Ask a stupid question, get a stupid answer
package ar.tools;

import java.io.UnsupportedEncodingException;
import java.security.*;

import javax.crypto.*;

import sun.misc.BASE64Encoder;

/**
 * This program will create a digital signature for the literal string
 * "students laptops into and out of the school compound".
 */
public final class DigitalSignature {
	private DigitalSignature() {
	}

	private static final String MESSAGE =
			"students laptops into and out of the school compound";

	public static void main(String[] args) throws NoSuchAlgorithmException,
			UnsupportedEncodingException, NoSuchPaddingException,
			InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
		System.out.println("Message:");
		System.out.println(MESSAGE);
		System.out.println();
		
		BASE64Encoder encoder = new BASE64Encoder();

		KeyPairGenerator asymmetricKeyGenerator =
				KeyPairGenerator.getInstance("RSA");
		asymmetricKeyGenerator.initialize(512);
		KeyPair keyPair = asymmetricKeyGenerator.generateKeyPair();

		System.out.println("Public key:");
		System.out.println(encoder.encode(keyPair.getPublic().getEncoded()));
		System.out.println();

		byte[] rawMessage = MESSAGE.getBytes("utf8");
		MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
		messageDigest.update(rawMessage);
		byte[] messageHash = messageDigest.digest();

		System.out.println("Message hash:");
		System.out.println(encoder.encode(messageHash));
		System.out.println();

		Cipher messageHashCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
		messageHashCipher.init(Cipher.ENCRYPT_MODE, keyPair.getPrivate());
		byte[] messageHashCiphertext = messageHashCipher.doFinal(messageHash);

		System.out.println("Digital signature:");
		System.out.println(encoder.encode(messageHashCiphertext));
		System.out.println();
	}
}

XP SP 2 OR SP 3 (SP2 is not updating)

I have just upgraded my pc but confused with XP SP 2 and 3. Which one I should I choose? Another thing is XP SP 2 (version 2002) is not taking any update (Though update is on) in my new system. But it took lot of updates in my old system. Why this is happening? —Preceding unsigned comment added by 119.30.36.53 (talk) 12:29, 28 July 2009 (UTC)[reply]

I think you need SP2 before you can get SP3, as far as I know you should get all, since they include bug fixes.
Start here http://support.microsoft.com/kb/936929 (check the prerequisites section for issues)
Just to save you time - if windows update is not working for you , you can get SP3 via a direct download here http://support.microsoft.com/kb/322389
Question - what's going wrong with 'windows update' is it not starting at all? does it go to the web page, or further than that? Have you checked that it is set to update at a time the computer is on etc? Have you already got SP2 installed.83.100.250.79 (talk) 12:51, 28 July 2009 (UTC)[reply]
You should definitely update to Windows XP SP3. There are many bug fixes, security updates, and feature updates involving Windows Firewall, among other things. The reason that on your system, Windows Update completed its cycle and said that your system is up to date even though it didn't download any fixes is that all of the Windows Update updates that have been created by Microsoft for the last couple of years have required SP3. Tempshill (talk) 14:34, 28 July 2009 (UTC)[reply]
Actually windows update should automatically install SP3 as well - which makes me think that windows update is going wrong - as it often does to me.
Curiously I just tried windows update and 'hey presto' I find that there is a high priority update to download and instal - which windows update has not told be about either - makes me even more suspicious that something might be (temporarily) wrong with windows update itself
To the OP - if the update gets stuck on the update page, just try again in 5 mins, and try pressing refresh (F5) as well - I would guess that providing updates to x billion computers occasionally causes server issues...
If that's not happening/working please tell how far you can get when trying to update eg when you visit http://windowsupdate.microsoft.com/ what happens?83.100.250.79 (talk) 17:19, 28 July 2009 (UTC)[reply]
They're separate and individual. One is not 'better' than the other. In order to use 3, you have to have either 1a or 2 already installed. There's no reason not to have all three; 3 is not an improved version of 2, they are completely different programs. HalfShadow 22:11, 28 July 2009 (UTC)[reply]

Answers: [14][15] also look at http://www.google.co.uk/search?q=does+sp3+improve+performance&hl=en&start=10&sa=N for more results.83.100.250.79 (talk) 13:38, 29 July 2009 (UTC)[reply]

Fujitsu laptop...possibly dead

My laptop has had a tendency of late of only working when plugged in to the mains, which is fine. Except last night when I loaded up as normal only to be greeted with my desktop full of "interference" and broken imagery. In a state of mild panic I unplugged the battery from the latop, following which the laptop duly died.

From last night onwards, I can turn the machine on - the on light is functioning and the DVD drive "clicks" to suggest it is being checked as per a normal process. From this point the thing doesn't go any further - no screen activity, no futher boot-up activity, no encouraging whirring noises, nothing.

Has my laptop passed on to the great customer advice centre in the sky, or is there something (anything?) I can do to solve what's gone wrong?

Many thanks in advance.....80.193.130.5 (talk) 13:41, 28 July 2009 (UTC)[reply]

Programming mouse buttons

How can I program my extra mouse buttons so taht pressing them will be the same as pressing a couple of keyboard buttons one after the other? So instead of pressing say, 2-b-b-1, I can just press the extra mouse button and it will be as if I pressed those buttons in that order? —Preceding unsigned comment added by 92.251.255.11 (talk) 15:42, 28 July 2009 (UTC)[reply]

Some mice with programmable buttons come with software to do that and manage other settings. See if your mouse came with a CD containing this software, or check the vendor's website for a download. Xenon54 (talk) 22:34, 28 July 2009 (UTC)[reply]
You didn't mention an OS, but for Windows AutoHotkey is a useful free program that can reprogram your mouse buttons do practically anything. -- BenRG (talk) 17:00, 29 July 2009 (UTC)[reply]

Plucker and Ebook readers

After the sad demise of Avantgo, I use Plucker and Sunrise to move online news articles and other content onto my Palm Tungsten E2. It takes a little effort, but generally works out. Can anyone tell me whether or not, and how (easily) Plucker-Sunrise content can be rendered and uploaded to a Sony PRS 505, or 700. My favorite app on the Ereader, I think, would be nytimes.com, economist.com, nameyourepublication.com...but I can't quite make out how those kinds of docs get onto that device. Thanks if you can advise. —Preceding unsigned comment added by 83.98.238.113 (talk) 18:11, 28 July 2009 (UTC)[reply]

Proxy

I was just wondering if there is any website from where i can get free live proxies... or is there anyother way to change the ip address ... as there are some sites where i cant enter because of my location , so i was like if i get some proxies of other locations and i use them for my explorer ?? And could you guys please guide me too , how to use proxy IN a proper right way ? Thanks in advance —Preceding unsigned comment added by 202.147.172.236 (talk) 21:44, 28 July 2009 (UTC)[reply]

How about Tor? It seems like that would simplify things a bit. --98.217.14.211 (talk) 22:10, 28 July 2009 (UTC)[reply]
Surely the original poster is not seeking to circumvent an impending IP block for his numerous vandalism efforts? Several warnings on the talk page seem to have had no effect. If you continue to vandalize Wikipedia as you did this morning, and on other earlier occasions, you can be blocked; and we're pretty good at figuring out you've come back with a new IP. Nimur (talk) 22:19, 28 July 2009 (UTC)[reply]
Tor is the standard for this, and, as Nimur is probably right, I'll note that Wikipedia doesn't allow editing from Tor proxies, or any other open proxies ... so I wouldn't waste your time, OP. Tempshill (talk) 23:53, 28 July 2009 (UTC)[reply]

When a computer was first activated

Is there any way to tell from your PC's files alone what date your computer was first activated? I checked the dates for the HDD and keyboard drivers, and both said 6/21/2006, which seems mostly accurate to me. However, I did this on another computer (bought about 8 months ago) and got the same results.--The Ninth Bright Shiner 22:36, 28 July 2009 (UTC)[reply]

That's unfortunately when the file system claims the file was created or modified. It does not mean that the computer that the file now resides on was active at that time. File-systems have varying conventions about reporting create-, modified-, and last-accessed- times. Many of the system files on my Windows XP machine all show create-times from before my computer ever existed (because when those files were copied from the install CD, they carried over the create- and access- times from the Microsoft developer's environment where they were actually compiled). Even if the file shows an access time for the true, correct date and time it was put on to the hard-drive, that only tells you when the hard disk drive was active - it tells you nothing about the motherboard, CPU, RAM, etc. Your harddrive could have been programmed by an OEM in a separate machine designed for pre-loading disk images, and then placed into your current system. Nimur (talk) 22:44, 28 July 2009 (UTC)[reply]
There may be a install date buried somewhere deep in the registry. I know, for instance, that there's a reboot counter, which might provide some interesting background. But I would suggest looking at user creation dates, most of all for the administrator user, but also for any non-admin users (most people won't delete the original account), and use that in connection with other created dates on the computer to get a pretty good idea of the first install. Also, you might be able to dump the NTFS headers and see when the filesystem was created. I don't remember for sure, but I think NTFS stores this information somewhere. There are other quirky ways you could probably figure this out, but try those few things and let me know if it works. Shadowjams (talk) 07:12, 29 July 2009 (UTC)[reply]

July 29

Game

What is the largest computer game ever made in terms of file size? Jc iindyysgvxc (talk) 00:47, 29 July 2009 (UTC)[reply]

Perhaps some game/movie hybrid? One were they would have to record more than the normal movie lenght? --Piotr Konieczny aka Prokonsul Piotrus| talk 01:07, 29 July 2009 (UTC)[reply]
I am going to guess that it is World of Warcraft. Most of the file data is of course on the WoW servers. I'm sure they store a gigaton of data that tracks player activity. Tempshill (talk) 01:39, 29 July 2009 (UTC)[reply]
I remember back in the good old days (ha) of CD-ROM gaming when games that used multiple CD-ROMs ran ads telling you how many floppies it would have taken to play the game as it was (Under a Killing Moon advertised itself as being the equivalent of HUNDREDS of floppy disks!). Ah, well. But yeah, as noted, are you asking about total size installed on a hard drive, or kept on local disks, or distributed on a network? Probably different answers in all cases. --98.217.14.211 (talk) 15:10, 29 July 2009 (UTC)[reply]
Metal Gear Solid 4: Guns of the Patriots says "Guns of the Patriots is the first PS3 game that uses a full 50GB dual layer Blu-ray Disc, even after extensive efforts in data compression." This might be the current record for local data, since publishers are presumably loath to require two discs. -- BenRG (talk) 17:13, 29 July 2009 (UTC)[reply]

How many wikis are out threre?

Are there any reliable estimates on how many different wikis are out there? Wikia claims to host at least 1,500. --Piotr Konieczny aka Prokonsul Piotrus| talk 01:06, 29 July 2009 (UTC)[reply]

It will be hard to reliably count. An overwhelming percentage of wikis are for "internal use only" in organizations, and are either not publicly visible or not publicly editable. If you intend to count non-public wikis, it will be very hard to come up with reasonable estimates. Nimur (talk) 01:32, 29 July 2009 (UTC)[reply]
Since the software is completely free in many cases, this question is like asking "how many non-wiki websites are there out there", but it's certainly lower than that. Chris M. (talk) 12:16, 29 July 2009 (UTC)[reply]

SQL Noob needs help

Hi All,

Is there an easy way to do this using sql: generate a table with two columns, one a field from the database and the other the number of times it occurs? Something kinda like: SELECT COUNT(CustID) AS totalOrdersFromCust FROM Orders_table WHERE CustID='id-here' except it will go and loop through the database so I end up with the number of times each customer has placed an order?

ex: 

custID    totalOrders
1         24
2         16

etc..

I know there's gotta be a better way the me having to write a loop with an external app.

Thanks in advance! PrinzPH (talk) 02:16, 29 July 2009 (UTC)[reply]

select CustID, count(*) as 'NumberOfOrders' from Orders_table group by CustID --Nricardo (talk) 02:50, 29 July 2009 (UTC)[reply]

Windows XP Hibernate Mode

Hello. How can I stop my computer from turning on immediately after hibernating it? There is more than enough space for hibernation. I read an identical question but it was unhelpful.

My computer spontaneously turns on only at 8 PM (EST) everyday. Regardless of when I hibernate my computer, the hibernation finishes but the computer turns on.

I was able to hibernate my computer even when I had an Ethernet card. Thanks in advance. --Mayfare (talk) 03:54, 29 July 2009 (UTC)[reply]

Reboot the computer and hit DEL (or whatever) to enter the BIOS screens, and scour the screens looking for the option to power on every day at a certain time, and, as was mentioned in the earlier thread, the option to power on when Ethernet packets are received. And any other options involving powering on; and turn them all off. Tempshill (talk) 04:05, 29 July 2009 (UTC)[reply]
Also go to Scheduled Tasks in the Control Panel and see if there are any tasks scheduled for 8 PM with "Wake the computer to run this task" checked in the properties (Settings tab). -- BenRG (talk) 08:18, 29 July 2009 (UTC)[reply]

Shell script issue

When I run the following shell script, I expect domain names which return data to wget to be listed on the terminal where I run the script, and those which don't to be listed on /dev/pts/4. Instead, all domain names are listed on /dev/pts/4. I've tried commenting out the for loop and instead setting $line to just one domain; if I do this, it works fine. What am I doing wrong with the loop?

On a related note, when iterating wget over 2070 domains that may all be hosted on the same server, are any precautions necessary to avoid triggering the server's DoS defenses? NeonMerlin 07:05, 29 July 2009 (UTC)[reply] 

#!/bin/bash
IFS="
"
for line in $(cat complete-scientology-domain-list.txt);do
  if wget -O - $line 2>/dev/null | grep ".*" >/dev/null; then
    echo $line
  else
    echo $line > /dev/pts/4
  fi
done
Setting IFS to newline means that any spaces in the input file will be treated as part of the URL. Don't set IFS and it should work. You should also put double quotes around all $line references. --Sean 14:41, 29 July 2009 (UTC)[reply]
To avoid triggering any defense mechanisms, check for a robots exclusion standard (GET /robots.txt). If the server is well-configured, the robots.txt file will specify rules for what you are doing (typically this means pausing between requests, e.g. pulling no more than one page per second, for example). Note that the robot exclusion "standard" is not really a "standard" - it is more of a guideline for "playing nice" with the host. A web server may choose to enact blocks or other defenses without specifying a reason. Nimur (talk) 15:40, 29 July 2009 (UTC)[reply]
Tried dropping IFS and quoting $line. Still doesn't work. NeonMerlin 16:21, 29 July 2009 (UTC)[reply]
Update: Does work correctly with the last domain name in the file (which doesn't end with a newline). Maybe it's an issue with how cat processes the line breaks. NeonMerlin 16:42, 29 July 2009 (UTC)[reply]

Bluetooth mice

Are bluetooth mice any good? I'm getting a laptop and wireless mice with a small receiver and bluetooth mice seem to be in the same price range, but I've heard quite a bit of bad press towards bluetooth mice. Are they really worse than normal wireless mice? Do they interfere with WLAN much? Thanks. --antilivedT | C | G 07:11, 29 July 2009 (UTC)[reply]

Not sure if what I'm saying is accredited but my Logitec one works great, just like a regular mouse, and works on pretty much any surface but ones with reflective coating. I'm glad I have one; the touchpads are pieces of crap in my opinion. -- penubag  (talk) 07:29, 29 July 2009 (UTC)[reply]
Bluetooth shouldn't (and hasn't, ever, in my experience with them) interfere with WLAN, or any other wavelength. Bluetooth has its own frequency, which coexists with the rest of 'em. [flaminglawyer] 13:18, 29 July 2009 (UTC)[reply]
Both Bluetooth and 'WiFi' use the 2.4GHz band. (excluding WLAN that uses 5GHz) There is the potential for a bluetooth signal causing the WiFi to operate at a lower rate. Other devices also use this bandwidth (eg xbox 360 controllers, some wireless telephones etc), additionally your neighbours WiFi may also be wanting some of that bandwidth too.
For a discussion (very technical) see the first three links of http://www.google.co.uk/search?hl=en&q=bluetooth+wifi+interference&meta=&aq=f&oq= to complicate things it seems that different devices may be better or worse than others - in terms of avoiding bandwidth conflict, as well as the relative power of there signals - it's complicated (business have to employ specialist engineers see if a big system can work) but a 25% reduction in WiFi WLAN bandwidth is possible even expected, and it can be worse.
In general though they work fine (in my experience) in a home enviroment.
You can get wireless mice that operate at other frequencies (eg 750MHz I think) - most suppliers will have this info about there mice, if you look at the tech specs.
If you are using WiFi WLAN as networking between computers and you require it to be as fast as it can possibly be then bluetooth is something to factor out. Under most conditions (internet browsing, small file transfers between computers) it shouldn't be an issue.
A lot depends on were you live - a new york office is going to be much more demanding (due to the number of devices all around) than a house in the middle of a park.83.100.250.79 (talk) 19:49, 29 July 2009 (UTC)[reply]

Updating flash on a psp 2003

Does anyone know how to update flash player on a psp 2003 as the version of the player was the most recent when the psp was new but now as newer versions of flash player have come out my older version does not work and I can't get onto youtube, bbc iplayer or any other site that uses flash because of it! Chevymontecarlo (talk) 08:07, 29 July 2009 (UTC)[reply]

See Sony's PSP update page for instructions, at the bottom of the page, on updating your PSP, by using a PC, a UMD disc, or, the easiest way, logging in to a WiFi network anywhere and choosing "Network Update". Tempshill (talk) 15:50, 29 July 2009 (UTC)[reply]

imaginary vbScript

Can vbScript handle complex numbers? If so, how does the syntax work? Thanks —Akrabbimtalk 14:38, 29 July 2009 (UTC)[reply]

According to [16] no.
There are modules that will add support via functions eg [17] , there are more extensive librarys which could be adapted using the same methods. eg [18]
A here's a list of some languages that do [19] if you need it.83.100.250.79 (talk) 14:51, 29 July 2009 (UTC)[reply]

trackboard

complete information about trackboard in computer —Preceding unsigned comment added by 116.68.94.36 (talk) 14:58, 29 July 2009 (UTC)[reply]

The only computer-related "trackboard" I've found is this product. If you have a specific question, please ask again and remember that you're dealing with people, not a search engine. --LarryMac | Talk 15:02, 29 July 2009 (UTC)[reply]
Google finds a company by that name that makes keyboards with embedded trackballs. But maybe you meant circuit board? -- Finlay McWalter Talk 15:03, 29 July 2009 (UTC)[reply]
or perhaps Stripboard ? -- Finlay McWalter Talk 15:14, 29 July 2009 (UTC)[reply]
Or maybe the mysterious semi-vaporware, Phantom Lapboard? Nimur (talk) 15:44, 29 July 2009 (UTC)[reply]
Did you mean Touchpad aka 'Trackpad' ? 83.100.250.79 (talk) 19:33, 29 July 2009 (UTC)[reply]

linux backup/restore

A couple of kinda related linux questions
1)when i installed linux (fedora 10) i installed /boot, /, and /home as separate partitions. Now the other day i had a slight hd drive problem, and decided i needed to reinstall /boot, how can i do this without having to reinstall /, as when i used a live cd installer it told it needed to install /
2) after reinstalling fedora i used rsync under root to copy back all the files, as i had backed up / on a removable hard drive, but it doesnt seem to of copyed back programs, the files seem to be there in the backup folder but it doesn't seem to of copyed back to my pc, anyway to fix this?
3) i currently use rsync under cron doing this command "01 18 * * * root rsync --archive --compress --backup --delete --exclude-from=/home/rob/exclude / /path/to/backup/directory' and exculde the following /media/ /proc/ /sys/ /tmp/ /mnt/ /usr/share/man/
a)is there any other files/folders that can be excluded
b)would running rsysnc with any different/extra options be more beneficent?
thanks--90.207.181.210 (talk) 16:49, 29 July 2009 (UTC)[reply]

MATLAB string analysis

I have a string: 

>> line = # GHZ S RI R 50.000000;

I want to grab each element as an individual string, and then convert the last into a number. After looking around, I tried this and got an error: 

>> header = regexp(huh,' ','split')
header = 
   '#'    'GHZ'    'S'    'RI'    'R'    '50.000000'
>> str2num(header(6))
??? Error using ==> str2num at 33
Requires string or character array input.

For all I can tell, header looks like a matrix of strings so I don't know why str2num isn't accepting it. Maybe it's just because I don't understand all this regular expression nonsense, but what am I doing wrong? Is there a better way to split this string? Thanks, —Akrabbimtalk 19:04, 29 July 2009 (UTC)[reply]

Does MATLAB indexing start at 0? If so, you'd want header(5). --19:37, 29 July 2009 (UTC)
No, it doesn't. It starts at one, so:
>> header(6)
ans = 
   '50.000000'

—Akrabbimtalk 19:40, 29 July 2009 (UTC)[reply]

While you're waiting for the answer - I can suggest a few things to try to see if you can find out whats going wrong - try the "ischar" and "isnumeric" functions on header(6), try the expression str2num("50.000000") to make sure the decimal isn't confusing it, also try passing header(6) to a single non arrayed variable eg 'tempv' and then using "str2num(tempv)" - to make sure the array isn't confusing the type checking on the function. I can;t actually see anything wrong myself.83.100.250.79 (talk) 20:28, 29 July 2009 (UTC)[reply]
I'm just guessing (again), but since nobody else has jumped in yet ... I've been perusing the online documentation and can't find anything obvious, but can you try header{6} ? i.e. curly braces instead of parentheses. I think header might be a "cell array" and you need to access the contents of a cell rather than the cell itself. --LarryMac | Talk 20:33, 29 July 2009 (UTC)[reply]
Actually I'm getting a bit confused because 'regexp' according to [20] has a different syntax, and doesn't do what you want - it checks for matches - you want to tokenise.??
You could try "strtok" see [21] —Preceding unsigned comment added by 83.100.250.79 (talk) 20:44, 29 July 2009 (UTC)[reply]

Time Machine on a Mac

Hi. I have recently purchased a 500GB Time Capsule to back up my iMac and MacBook Pro. I first set up Time Capsule on my iMac and all was hunky dory. However, when I tried to set it up on my MacBook Pro, it came up with 'Time Machine Error. The backup disk image could not be created.'. I haven't the faintest idea what this means or, more importantly, how to rectify it. Could someone help me out please? Thanks. 92.0.232.90 (talk) 19:42, 29 July 2009 (UTC)[reply]

That error means that the Time Machine program could not create the database for saving old versions of your file. According to this Apple discussion forum, you need to set your computer's "Network Name" (in the System Preferences utility, this can be set in the "Sharing" tool, under "Computer Name"). Time Machine probably requires a computer name to be properly set so that it can create a unique database just for that computer. Nimur (talk) 20:01, 29 July 2009 (UTC)[reply]
This is no doubt going to jinx it but setting a Network Name (which I did not have before) got everything going just like with my iMac. Thanks Nimur! 92.0.232.90 (talk) 20:22, 29 July 2009 (UTC)[reply]

Apples ownership of adobe systems

Can you tell me what the high watermark percentage of Apples ownership of adobe was? I know that at one time they owned more than 16% but I think the high watermark was closer to 25%. Brafferty (talk) 20:31, 29 July 2009 (UTC)[reply]

Switching from GPL to closed source

The AutoHotkey article states that the authors released their code under the GPL, became frustrated, and then declared their future work with the code base was to be closed source. In the cited source (it's a chat board thread), the apparent author of the software states, "As we wrote all the code we can depart from the GPL if we choose. Previously downloaded source would still be under GPL (as per the license) but new copies of the source would be under whatever license we care to make."

Is this correct? I know there's very little case law in any country regarding the GPL, but I guess I had thought that once the author releases code under the GPL, he is a licensee as well, and as a user of the code, would have to abide by the GPL's terms, including releasing free, GPL'ed source code of any derivative works. If the author's statement is correct (and it does sound logical to me that he doesn't have to be a licensee) then that's an interesting wrinkle. Tempshill (talk) 20:46, 29 July 2009 (UTC)[reply]

My understanding is that only the copyright holders may sue if there is a breach of the GPL. If all copyright holders decide that they do not want the GPL and will not sue about ending the GPL license, then the license may be changed without any legal problems. It is the perception of the people that once something is GPL it is absolutely free and owned by the world. That is a completely false perception. Having such a perception leads to the perception that the copyright holders are stealing from the world by taking their code closed source. -- kainaw™ 20:56, 29 July 2009 (UTC)[reply]
(edit conflict):I can't see any stand up argument that would prevent someone/group changing the licencing arrangements for their own work (assuming no other contributers disagree) applying to future products (retroactive license changes are non-runners though) - the license isn't a contract that requires the producer (ie the one with the intellectual property rights) to continue to license all their work in perpetuity.
As you say the manufacturer is not a licensee.I'm not a lawyer83.100.250.79 (talk) 20:57, 29 July 2009 (UTC)[reply]

Video Conversion

Is there any free software that i can use to convert dvr-ms (the format used by recorded tv from Windows Media Center) to a common format such as mpeg or avi. I have tried avidemux but the audio is really out a sync and i generally cant get it to convert correctly. Any ideas on good video conversion software or how to use avidemux properly would be greatly appreciated. —Preceding unsigned comment added by 86.177.127.22 (talk) 21:07, 29 July 2009 (UTC)[reply]

Retrieved from "https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Computing&oldid=304954729"