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April 14

USB vs. headphone jack computer speakers

It seems that some speakers that work with laptop computers go through the USB port while others plug into the headphone jack of the computer. Is there an advantage to one type or the other? -- Mwalcoff (talk) 03:10, 14 April 2008 (UTC)

Advantage of the headphone jack: you already have one, you're not taking up a USB port.

Advantage of the USB port... I guess you could use it at the same time as you used the headphone jack? Usually these have their own soundcard so if you have a lousy soundcard I guess this could be useful. But otherwise.... no.

But honestly—I don't think there is any advantage of USB speakers. There's certainly no quality advantage, if that's what you're asking. --98.217.8.46 (talk) 03:17, 14 April 2008 (UTC)

It's pretty much personal preference. I have used many different types/brands of speakers on my computer, and in the last year, two comparative models, one USB, one headphone jacked, on my laptop, and I haven't found a true division between the two. Now, this is just one case, and I can't by any means say that it will always be this case, but this is just what I've found. Mastrchf91 (^t/_c) 03:27, 14 April 2008 (UTC)

The reason why I use USB instead of the headphone jack is that my laptops jack isn't working real well anymore (you have to wiggle it around, and often it is impossible to get sound to both of your ears, I suspect some wire has gotten loose and some soldering will fix it, but using the USB-headphone is just easier). That's pretty much the only reason I know why someone would switch. —Preceding unsigned comment added by 83.250.207.154 (talk) 03:41, 14 April 2008 (UTC)

Thanks. I was more concerned that the inexpensive Logitech X-140 speakers I was going to buy wouldn't work with my laptop and that I would have to buy more expensive USB speakers. But it looks like the X-140s do work with laptops via the headphone jack. -- Mwalcoff (talk) 04:08, 14 April 2008 (UTC)

USB speakers are nice in that the speakers can have power via the USB port and turn off and on with the PC. Cheap slow USB hubs are dirt cheap if you are running low on ports and keyboards, mice and speakers can use it.--Wonderley (talk) 05:34, 14 April 2008 (UTC)

My tablet has some pretty irritating interference noise that shows up in the headphone jack. I use a USB -> audio adapter to get around this issue. I can't think of an advantage of that sort of device if your headphone jack works the way it's supposed to, but lots of older computers have really crumby sound cards. APL (talk) 14:14, 14 April 2008 (UTC)

I don't like USB ports for two reasons:

1) Unlike a headphone jack, the rotation of the plug must match exactly. A USB port is better than a PS2 port (which is round and requires a specific rotation, meaning you may have to try an infinite number of rotations until you find the right one). Since a USB port is rectangular, there are really only two orientations you are likely to try, but I am still forever trying to plug them in upside down, especially when the USB port is tucked behind the computer so I can't see it or pointed down, as in some Dells, so again I can't see it.

2) USBs can "sag" in the port, with the weight of the cord pulling it enough so that it loses the connection. StuRat (talk) 17:30, 14 April 2008 (UTC)

Never heard of sagging. Does it happen often? Kushal 20:25, 14 April 2008 (UTC)

It's more common with a USB pen drive since they are a bit heavier, but yes, it happens occasionally. The orientation of the slot also matters. It's more likely to happen if the USB slot is horizontal than vertical. StuRat (talk) 21:44, 14 April 2008 (UTC)

In theory, a USB connection is of higher quality, because the signal stays in the digital domain longer. It only becomes analog right at the amplifier. With the headphone jack (coaxial) connection, the signal becomes analog inside your computer, and can pick up interference on the way to the amplifier. In practice, however, it doesn't really seem to matter. --Mdwyer (talk) 04:49, 15 April 2008 (UTC)

But if the USB speaker is using bad DAC's and amplifiers... Bad DAC's and amps are much more noticeable than computer interference, though you probably wouldn't hear any of it with those speakers. Also, 3.5mm jack does not equal to coaxial. --antilived^{T | C | G} 08:36, 15 April 2008 (UTC)

Has anyone mentioned that USB offers more power for speakers and the like than just the standard headphone jack? Mix Lord (talk) 01:01, 17 April 2008 (UTC)

Yeah, the only difference is the ned for power. Headphone only speakers will be weaker. Headphone jack with additional power would sound better than just usb. 86.139.92.22 (talk) 11:19, 19 April 2008 (UTC)

MMORPG staff

(Copied from Entertainment desk) In a typical MMORPG's staff, does the lead programmer report to the lead sysadmin or vice-versa? NeonMerlin 16:27, 14 April 2008 (UTC)

Neither, I'd guess. The sysadmins are on the operations side of things, while the programmers are on the development side of things. They most likely both report to someone higher than themselves -- a VP or higher. --Mdwyer (talk) 04:45, 15 April 2008 (UTC)

This is from May 2004 Game Developer magazine :

SOE has established a separate operations department (about 30 people) who buy, set up, and maintain our game server hardware, push patches for all of our live games (including PlanetSide, Star Wars Galaxies, and EverQuest Online Adventures for PlayStation2) and monitor all the game servers 24 hours a day. The operations department does not report into the game development structure. They are totally separate and equal within the company. They have the power to say "no" to the game teams, and frequently do. This separation of power may seem extreme. For example, no game development team is allowed to push a patch to our customers. Instead we put in a request to Ops, who then push the files out to all servers after running their own checks, which includes checking with our QA group to make sure the patch has passed testing.

They go on to talk about how the programming and art departments have someone "on call" 24/7 in case there is a problem with the live servers. It's an interesting article. Worth looking up if MMORPGs are your thing. APL (talk) 13:03, 16 April 2008 (UTC)

black box on power cord

Dumb question, but I have wondered what the black box on the power cord for my laptop is.... the purpose. Thank you. Alicia —Preceding unsigned comment added by 24.113.8.103 (talk) 16:32, 14 April 2008 (UTC)

The article isn't great, but Wall wart covers some of this. I believe they generally are transformers. Friday (talk) 16:39, 14 April 2008 (UTC)

There are two possibilities. It could be an AC-to-DC power transformer. It could also be an interference filter. While they are not as common on power cords as signal cords, I have seen them on multiple laptop power cords. How do you know which is which? The transformer is wired into the power cord. It is either a big wall-wart that plugs into the outlet or a foot-heater than sits on the floor with the power cord stuck in both sides. An interference filter is usually a little donut shaped thing that slides over the power cord. Sometimes they snap a plastic box over it to keep it from sliding up and down the cord. -- kainaw™ 16:46, 14 April 2008 (UTC)

Mainly it does electric power conversion. A laptop will typically require low voltage (on the order of ones or tens of volts rather than hundreds) and a DC signal rather than AC. The wall output supplies a 50-60 Hz AC signal with RMS voltage of 110-240 V. The specifications for the output signal (laptop's input) and the allowed input signals (output of the wall socket) should be listed on the box itself. Some may also provide some additional surge protection. --Prestidigitator (talk) 17:00, 14 April 2008 (UTC)

Pictures of the intereference filter? See the ferrite bead article. --Mdwyer (talk) 04:43, 15 April 2008 (UTC)

Windows Vista posting a lot of nonexistant and double entries

See [1]. I consider this to be a sincere pain in the neck, and so I'm asking if anyone knows how to get rid of them. The empty files are a pain (clicking on them does nothing), and the duplicates are a pain (clicking on them shows they're the same folders) - there are documents only for the "my ..." objects. Is this a common error (I suspect it is), and how do I fix it? The computer did not always do this on Vista. At this point, I would prefer not to ignore it. Thanks.

PS. This might have something to do with an older user which I set up, and which is now removed from the computer, though, like I said, both links are to exactly the same folders on the hard disk. Chrissekely (talk) 16:50, 14 April 2008 (UTC)

Full harddisk backup - including operating system

Hi, my laptop is facing replacement of the wireless circuit for the second time in less than two years (I'm not buying a HP next time). They're replacing it for free, but I have to send in the computer and I guess they can't guarantee they won't wipe the hard drive. I'll back up the contents to DVDs and an external (USB) hard drive. However, it takes an evening to reinstall Windows XP including all the custom HP drivers that have to be installed in a specific order (and no, I don't want to use the HP recovery disk for various reasons). My question: Is there a backup utility, preferably run on a LiveCD, that will make a backup image of my harddisk on an external hard drive or DVDs? Then, if I get my computer back with a wiped drive, I could run the same LiveCD, restore my hard drive and operating system from the external backup and simply boot Windows from the hard drive after that. Any inconveniences encountered from replaced circuitry would be minor, I suppose, Windows usually handles that okay. Thanks! Jørgen (talk) 17:28, 14 April 2008 (UTC)

Symantec Ghost, Windows Home Server, Acronis True Image, ImageX and lot of others. --soum ^talk 17:31, 14 April 2008 (UTC)

I use Symantec Ghost and love it. If you also have a desktop, they make an adapter that allows you to connect a laptop hard drive to another computer and it makes all this even easier. The adpater is very inexpensive. I don't have one, but a friend of mine did and it worked great. I don't know where he got it, but it looked like this one:

http://www.cablestogo.com/product.asp?cat_id=906&sku=17705 --Wonderley (talk) 20:34, 14 April 2008 (UTC)

Don't send the hard drive to them at all. In general you should send in only the component that needs replacing and anything else that you can't detach from that component without voiding the warranty or risking damage. Hard disks and RAM are user replaceable on most laptops, and a reputable repair house will not need either one to replace your wireless card. Disreputable repair houses (which may contract with major vendors) have been known to, e.g., swap out expensive RAM with cheaper RAM and hope the user won't notice. Remove everything you can. -- BenRG (talk) 12:29, 15 April 2008 (UTC)

I imagine you could also use GParted for this sort of thing too, just copying partitions from one drive to another. --Captain Ref Desk (talk) 14:02, 15 April 2008 (UTC)

Thanks all! While reading the first answers I actually thought about the last two and I think I will try one of them (picking out the hard drive or using GParted, which as far as I understand is both free and CD-bootable) Jørgen (talk) 14:35, 15 April 2008 (UTC)

I cant go to Yahoo and Google,but I can still go to Wikipedia?!?!

I cant go to www.google.com or to www.yahoo.co.uk or to myspace,but I can still go to Wikipedia and some other sites?!?! Why is this happening? It started this morning! 79.175.80.90 (talk) 17:36, 14 April 2008 (UTC)

Any error messages? CaptainVindaloo ^{t c e} 17:56, 14 April 2008 (UTC)

Who (if anyone) has access to your computer besides you? What new software (if any) have you installed? What method do you use to log in and connect to the Internet? It could be any of several hundred different things, and without some background you're probably not going to get much in the way of useful help. It could be a late april fool's joke where someone modified your lmhosts file.

mac & pc

What is Mac, and how is it different from PC? Which one is better for professional users, and why? please post your best answer as soon as possible. i want the nswer for my assignment —Preceding unsigned comment added by 202.125.143.66 (talk) 17:58, 14 April 2008 (UTC)

We have articles on Apple Macintosh and Microsoft Windows.. those might get you started. Friday (talk) 18:03, 14 April 2008 (UTC)

It's my obligation to pop in and say that a Mac is technically a PC as well. I also hate those "Mac vs. PC" ads with an undying passion (Why haven't they made one about gaming? Oh, that's right, because it would go against them!). What do you mean by "professional" users? Offices, by and large, use Windows for both servers and workstations. Using Macs for these purposes would be ridiculous. Unix and Linux are used as well. So Macs are definately not for professionals, unless they are graphic designers or something. If you want even more professional, look at Unix and Linux. 206.252.74.48 (talk) 18:55, 14 April 2008 (UTC)

Businesses won't usually buy Macs in large quantities because Apple really doesn't gear its business model towards business purchasers right now. Dell and the like are better there, for prices, flexibility, and support. It's not unheard of to see 'professionals' with Apple laptops though. Server wise, Mac OS X Server isn't that bad (OS X being a Unix), and not completely unheard of; though again, companies like IBM primarily use Linux and are far more popular business-wise. -- Consumed Crustacean (talk) 21:16, 14 April 2008 (UTC)

A PC is a personal computer. It refers to any computer one would expect to see in a person's home as opposed to a server room at a large company. A Mac is a Macintosh computer, which is also a personal computer. A Mac is a subset of PC - it is a specific line of PCs made by Apple. It is far more likely that you are asking "What is the difference between Mac OS and Microsoft Windows?" They are both window-based operating systems. They run programs. Programs written for one rarely work on the other. So, the main deciding factor between the two is usually based on the software that you need to run. Another alternative (mentioned above) is Unix/Linux. There are many free variants of Unix/Linux. Of course, it is rare to get programs written for Windows or Max OS to run on Unix/Linux efficiently. So, again, the decision to use (or not use) Unix/Linux is based on the software you need to run. -- kainaw™ 19:13, 14 April 2008 (UTC)

You might consider reading [this] version of an essay, originally In the Beginning...was the Command Line by Neal Stephenson. Kushal 20:18, 14 April 2008 (UTC)

Just wanted to stick up for OP's use and understanding of the expression "PC". It's fine - in this context it's concise and unambiguous. Your teacher doesn't want to have to read "x86 based computer running a Microsoft OS, of the type often found in a home" every two lines or so. Good luck. --90.209.36.146 (talk) 21:21, 14 April 2008 (UTC)

There seems to be an urban myth that mac is better suited for graphic and video applications and so on. But that is not true as most programms used by professionals like photoshop etc.. are available for both windows and mac. Whats more important is a good profiled screen and a professional video interface.

Professionals can and do use both. At the moment they are functionally equivalent for most purposes and it is a matter of preference. Windows machines often have more trouble with malware than Macs, on the whole, and Macs, on the whole, are more expensive than PCs and harder to modify at a hardware level. There are lots of little trade-offs in either direction. --Captain Ref Desk (talk) 13:09, 15 April 2008 (UTC)

I don't think the original questioner wanted a debate over which is better, so let's return to the basic differences. The major difference between Macs and PCs is that they run different operating systems -- Macs typically run Mac OS X, while PCs typically run Microsoft Windows. (Some computers that would be called "PCs", which is a pretty vague term as discussed above, run other operating systems such as Linux. This is less common, but possible, on Mac computers.)

Because they run different operating systems, they have different software available to them. And perhaps the most immediately noticeable difference is that the graphical user interfaces of Mac OS X and Microsoft Windows are fairly different. I hope this helps. rspeer / ɹəədsɹ 18:10, 15 April 2008 (UTC)

Automated description of graph features

Does anyone know if any work has been done on having a program interpret a graph (or a dataset) and describe its features? For example, the software would be able to look at a noisy graph and say "The graph has a positive slope between here and here, and then plateaus here, and then starts curving back down to zero," or something. In other words, describing a graph much like a human would.

Anything like that already, or any research being done on this?

— Sam 20:01, 14 April 2008 (UTC)

Maybe someone has, but if not: any mathematically-aware programmer (or programming-aware mathematician) could come up with something like this in a couple of hours using existing software (Maple, Matlab, etc) to do the actual calculus (or modelling). —Preceding unsigned comment added by 90.209.36.146 (talk) 21:40, 14 April 2008 (UTC)

Well, I don't know that that's actually the case, which is why I was asking. I'm an AI researcher, and I can already see a large number of difficulties. The key problem is that the computer has to "chunk" the graph into the same set of features that we see when we look at the graph. It has to know whether a graph is bumpy because that's a "feature" or because of noise. It's certainly not impossible, but I don't believe it's a couple hours work. — Sam 13:23, 15 April 2008 (UTC) —Preceding unsigned comment added by 205.234.170.131 (talk)

Not an optimal solution, but you could preprocess it with some sort of filter (like a Hodrick-Prescott Filter, but something else would probably be more appropriate) , then try to fit a third (or higher)-degree polynomial onto this function and finally have your program interpret the result based on the resulting tops, bottoms and inflection points? Jørgen (talk) 14:34, 15 April 2008 (UTC)

Given that the HP filter is a cubic order filter anyway, you may as well just fit the polynomial to the original. You could try fitting polynomials of degree 1 to n-1 (where n is your number of points), and pick the one with an optimal combination of fit and low degree (e.g. try to minimise degree + some constant * amount of variation around polynomial fit). You would then be able to analyse everything in terms of the polynomial rather than the original series. Confusing Manifestation(Say hi!) 04:52, 16 April 2008 (UTC)

Computer on TV

I recently purchased a 'VGA to TV Converter S-Video+RCA out cable adapter' so I could put a PC on my TV, but I cant seem to get it to work!

I've tried everything including having the pc hooked up with just the S-video cable, with just the RCA video cable and both. Any suggestions would be great :)

Thanks!! --Zach (talk) 21:15, 14 April 2008 (UTC)

Do you have the TV on the right input? Useight (talk) 21:21, 14 April 2008 (UTC)

How exactly does it fail to work ? Does the TV only have static on it ? If so, there may be multiple input modes to select from, like "cable", "antenna", "S-video", etc., that you can toggle through using the remote control or directly on the TV. StuRat (talk) 21:34, 14 April 2008 (UTC)

DSL and my IP address

I have noticed that my IP address changes from time to time, but I as yet have not undertaken the research to determine exactly when or how often I get a new one. I'm using my phone company's offering, so I have a DSL Modem with 4 little green lights; I note that the LGLs stay on when the computer sleeps, but upon waking up it takes 10-15 seconds before mail, browsers, etc are able to communicate. One explanation might be, upon sleeping my IP address is released, and upon wakeup a new one must be acquired, which takes a few seconds.

Anyone with real insight as to how that process actually works? It's pretty clear that I get a new IP after rebooting; do they really get dropped and reassigned more often than that?

The other thing that surprises me (I'm old, so a lot of current technology does that) is that, today for example I seem to be 209.181.somethingelse, which might be a nice, traditional Class C address. Yesterday I was 89.61.something, a B address. I would have expected Qwest has a pool of IP addrs (all in the same domain, yes?) that it would draw from as needed, and therefore the first couple of octets would stay the same from assignment to assignment. Apparently not.

Sharing of wisdom appreciated!

--209.181.224.8 (talk) 22:14, 14 April 2008 (UTC) Danh

Well, I'd say see DHCP which what they're no doubt using to assign your IP address. I'm not sure under exactly what circumstances it will try to get a new address. But when it tries to get a "new" address, it doesn't necessarily change; if the "old" address hasn't been assigned to anyone else it will may be assigned back to you. (My machine here has had the same IP address for something like two years. But it might change anytime.) As for the address ranges... It's possible that they have more than one pool of IP addresses. Like they had one and needed more, or something. Also, the whole "Class C" address thing is mostly moot nowadays -- address blocks come in many more sizes independent of the "class" of the address; see CIDR about that. -- Why Not A Duck 23:21, 14 April 2008 (UTC)

As Why said, take a look at the DHCP article. The short version is that you are given a 'lease' on an IP address for an amount of time. That time is not standard, and is configured in the DHCP server. Usually, when your lease time expires, you can renew the lease, and you'll get the same IP back. However, if you're offline and your lease expires, the address will be given to someone else. When you log back in, the server will find a different address in the pool to give you.

Assuming a Windows machine, if you get to a DOS command window and type "ipconfig /all" it will show you information about your lease, include when you got it and when it expires.

About that pool: Yes, Qwest has a pool of IP addresses, but those pools could be from all over. Keep in mind that Qwest is the product of a lot of smaller companies merging together. Still, geographic regions typically stick to one octet. For example, out here, the addresses are all 71.208.x.x.

Finally finally, I hope your other address is a typo... 89.61.0.0 is in RIPE space -- that is, it is registered in Germany. You should NEVER have received that address from a Qwest DHCP server. I used the WHOIS tool to look up the IP owner. --Mdwyer (talk) 04:39, 15 April 2008 (UTC)

April 15

Unistalling Skype

I have been trying to re install Skype but I keep getting a message "the older version of Skype 3.6 cannot be removed. I have done the Add/Remove bit through the control panel and Skype no longer appears there, I have gone through the Documents & Settings / Application Data folder and removed all references there and I have searched for registry entries through Regseeker and removed all through there but the message keeps coming up. Any ideas, thanks. —Preceding unsigned comment added by Michaelerrington (talk • contribs) 09:40, 15 April 2008 (UTC)

Do you still have the Older version of Skype? If so, re-install it, then re-boot the pc in 'safe mode' and run the add/remove bit again. That should shift it. Incidentally, have you checked through the *.ini files, the config files and so on? Remove all references to Skype in these, and you might avoid the need to re-install Samilong (talk) 09:30, 16 April 2008 (UTC)

Simple method to get the filename out of a URL?

Hi all, I'm trying to work out a simple method that you can pass a URL and it will return the file name of the file. So, if you pass it "http://www.example.org/example/file.txt" it will return "file.txt."

Java would be best, but anything would be helpful. I assume I need a regular expression, but my knowledge of regex is very limited.

Thanks! — Alice 16:10, 15 April 2008 (UTC)

import java.net.*;
static String get_file(String url_string)
  throws MalformedURLException
{
        String filename = new URL(url_string).getPath();
        int slash = filename.lastIndexOf('/');
        if (slash >= 0)
            filename = filename.substring(slash + 1);
        return filename;
}

You want to look for everything after the last slash? To be pedantic, there's nothing in a URL that you can assume will always correspond to a filename. So, figuring out in English what you want to accomplish is probably where the real effort belongs on this problem. Translating that into code should be fairly trivial. Friday (talk) 16:41, 15 April 2008 (UTC)

The URI spec breaks it up into well-defined chunks. --Sean 16:48, 15 April 2008 (UTC)

But thanks to the rewrite engine, you can never really be sure (from outside the server, at least) what file will actually be invoked from any given URI. I think that's one thing that Friday was cautioning about.

Atlant (talk) 16:57, 15 April 2008 (UTC)

There's nothing that says there even has to be a file name. The server is free to handle that string any way it likes. For example : There's no filename in a TinyUrl.com url. There's just a unique ID that the server interprets. APL (talk) 17:00, 15 April 2008 (UTC)

You could probably use java.net.HttpUrlConnection to first do a GET request and check the 'Content-Disposition' HTTP header for a file name. If that fails you could, as in your example, try to infer a file name from the last path segment. The mime type identified by the 'Content-Type' HTTP header of your GET request might also be useful if you need to come up with some kind of file type/extension to make your file manager happy. If you are simply looking for something to help you parse the URL's path portion, you might take a look at the java.io.File class. --Prestidigitator (talk) 18:16, 15 April 2008 (UTC)

C#: remove \x00

<noob> I've just started using C#, and can't find a way to remove a null byte from the end of a string. My application is supposed to accept incoming files via Bluetooth (OBEX), and they for some reason get saved with a null byte after the filename. (Which I always thought isn't allowed by the filesystem.) TrimEnd(new char[] { '\0' }) doesn't work. (I'm really new to C#.) </noob> --grawity ^{talk / PGP} 17:21, 15 April 2008 (UTC) P.S. Prepare for a flood of C#-related questions.

In C, strings are null-terminated. I'm sure this has something to do with the strings you're receiving. I don't know the first thing about C-octothorpe. -- Coneslayer (talk) 17:28, 15 April 2008 (UTC)

Yes, but the null should be used only as a terminator, and not displayed to the user. Anyway, I've noticed that it's actually 0xFFFD, not null - something with the InTheHand library (which I use for Bluetooth). --grawity ^{talk / PGP} 17:57, 15 April 2008 (UTC)

0xFFFD is Unicode's way of representing a character that could not be translated into Unicode. Clearly some function that you're using is making a wrong assumption about what character set it is reading (like whether it's Unicode or single-byte characters). That's all I can say. --Anonymous, 23:14 UTC, link added 23:37, April 16, 2008.

Security of BitTorrent

Hi. How secure – data-wise – is BitTorrent? If I'm downloading a Linux distro CD set, can some seeders modify and inject rootkits or the like in the pieces they host? ›mysid (☎∆✎) 18:24, 15 April 2008 (UTC)

Downloading an OS via torrent sounds to me like an exceptionally bad idea. Darn right you could be getting something with a rootkit in it. Why not download directly from a domain you can trust, rather than a bunch of peers? You want to be able to trust your operating system. Really you do. I guess if you REALLY need to do this, at least make sure you are getting the torrent file itself from a trusted source, and verify checksums obtained from an official distribution site to give you some assurance that the files haven't been tampered with. --Prestidigitator (talk) 18:52, 15 April 2008 (UTC)

If you get a torrent from an official site, you can generally be assured that it's likely to be legitimate. Lots of distros have torrent (i.e. http://torrent.ubuntu.com/). x42bn6 Talk Mess 19:22, 15 April 2008 (UTC)

"Why not download directly from a domain you can trust, rather than a bunch of peers?" Easy. The project that creates the disk images is a not-for-profit, and they appreciate anything you can do to reduce the load on their servers. Especially since you, and everyone else, are probably downloading multiple CDs worth of stuff. APL (talk) 20:27, 15 April 2008 (UTC)

Many free software projects publish checksums of their packages on the official site. For example, halfway down the [OpenSUSE download page] there is a link to md5sums of the ISO disk images. The idea is that you can download the distribution off P2P or a local mirror site, then compute the checksum using a utility program such as md5sum and check the result against the checksums on the official site. If the checksums match, then you can be confident that what you got is the official distribution package and that it's safe to run it. 84.239.133.86 (talk) 20:00, 15 April 2008 (UTC)

I think the answer to the question of whether seeders could inject things is probably "no"—it would definitely throw off the seeder hashes and there'd be very little chance of it all working correctly. Modifying an individual torrent chunk would register as something very wrong to a tracker, I am fairly sure, and it'd be a very difficult thing to pull off in any case (since you wouldn't be sure what chunks would be requested at what time). (Of course, the original distro could be modified from the beginning, but that isn't what I took your question to be.) --Captain Ref Desk (talk) 20:12, 15 April 2008 (UTC)

You're talking about taking a .torrent file from a trusted source, and injecting bad data chunks into it by seeding tainted data? This is not realistically possible. To do this you would need to first crack the [[SHA hash functions|SHA1 hash.] It's relatively safe to say that this can't be done.

Note that it is possible to turn off hash checking on some torrent clients, but that's apparently just intended for debugging purposes and no one should actually be running like that. Even if only because bittorrent's somewhat large packets occasionally get mangled, particularly by home routers.

In any case if you wanted to feel even safer you could check against the checksums that are usually published by the creators of the disk images. APL (talk) 20:27, 15 April 2008 (UTC)

Thanks for all the answers. ›mysid (☎∆✎) 05:27, 16 April 2008 (UTC)

I'm pretty sure torrents come with a hash check built into them, so if someone attempted to modify the data being transfered the torrent client would notice the data doesn't match the hash and dispose of it. So as long as you got your torrent from a legit source the file should be safe, especially if its a Linux iso that you got from that distibutions official website. TheGreatZorko (talk) 08:08, 17 April 2008 (UTC)

April 16

what was that filesystem bit called? stupid bit?

I have a vague recollection of reading about this filesystem bit from bygone days of computing. It was a filesystem attribute which did something annoying. Keep the file from being copyable, or executable, or readable, or something, I forget. To bypass the restriction, anyone with the right know-how could simply toggle that bit. I believe it was for an old Macintosh or maybe even Apple II operating system, but I'm not sure. And it had some cute name like "the stupid bit" or "the dumb bit". I may have read about it in a recent John Siracuse Mac OS X review, but if so, I can no longer find it.

Does anyone know what the heck I'm talking about? Thanks -lethe ^{talk +} 02:36, 16 April 2008 (UTC)

I don't know my DOS has the Archive bit, which was supposed to be used to be cleared upon writing, so you can tell if the file needed to be backed up. Old Unix machines had a Sticky bit, which was used to tell the computer to try to keep the code in memory. It has different uses today. I don't see anything at Apple ProDOS, Apple DOS, or Hierarchical File System but you might look at Category:Disk_file_systems. Also, the old Zip disk didn't have a physical write-protect system, so you could unprotect a disk without the user's intervention. --Mdwyer (talk) 03:55, 16 April 2008 (UTC)

Check out this link. I guess this is what I was thinking of? "The Bozo bit".

"My first encounter with a Bozo bit was in the Mac Resource Fork contents, described in Inside Macintosh for the 128K Mac. The rumor then was that it identified MS code, although Multiplan (the first wysiwyg spreadsheet) was not yet out. I had always assumed that was its origin -- does it go back further?

The BOZO bit you're talking about was a rather lame attempt at copy protection. Utilities that copied files were supposed to check to see if this bit was set; if so, the utility should refuse to copy the file. It took nanoseconds for someone to write a utility that ignored the BOZO bit. This sounds like the same thing as the Broadcast Flag?."

I don't know where I would have heard of that though... -lethe ^{talk +} 08:05, 16 April 2008 (UTC)

non-wiki contributions (2)

Earlier I asked what website solutions, other than wikis, exist that enable users of a site to add content such as answer and post questions? Thanks to everyone who answered, but I think you get the wrong end of the stick. What I meant was software solutions, hopefully opened source, like the software behind yahoo answers etc or a clone of it. —Preceding unsigned comment added by Mr nibble (talk • contribs) 08:54, 16 April 2008 (UTC)

If you are into blogging, WordPress could be just right for you. There is also a good list of CMS at the English Wikipedia. If you have a bit of time, why not play around in List of content management systems? You should be able to set up blogs and anyone will be able to answer your questions via the comments feature. I hope it helps. Kushal 20:46, 16 April 2008 (UTC)

Skype problem

A friend of mine installed Skype (in Cambridge in the UK) but when I call her (from Birmingham in the UK) I often hear two rings followed by the engaged signal. When I do get through she says the phone didn't ring earlier and she wasn't using it. Now other people report the same problem and it also happens with someone else in her office who has a separate Skype number. Does anyone know if this is a common problem with Skype or might they have set it up wrong?--Shantavira|^{feed me} 10:37, 16 April 2008 (UTC)

• "When in doubt, reinstall" My first suggestion would be to reinstall on both ends, and if that doesn't work it is probably either your ISP or Skype.

Thomaso.mirodin (talk) 13:54, 18 April 2008 (UTC)

Smart card questions

I have been researching and experimenting with PKI under Linux and I have a few questions about storing private keys and identity certificates on smart cards.

• I've read that some smart cards can perform RSA, etc., functions on the card. Does this mean they can store private keys encrypted on the card which are decrypted on the fly with the PIN when the private key is needed? This seems more secure than relying on tamper-resistant designs to try and secure a unencrypted key in memory.

• I've read that SIM cards and smart cards are basically the same thing, but different physical form factors. Can you buy blank SIM cards to store certs on like blank smart cards? Can they be read with a normal SIM card reader like a smart card reader? I really like the smaller form factor, which could be hole punched and put on a key ring instead of in a wallet.

Thanks for any input! 66.75.102.95 (talk) 11:00, 16 April 2008 (UTC)

Let's start with some generalities. A smartcard contains a so-called module (the chip with the metal contacts on top). There are a variety of card form factors but the modules follow the same spec. The module communicates with the reader using a serial link. ISO/IEC 7816 describes this interface. This includes the mechanical and electrical specifications, the properties of the serial link and the base communication protocol. What this means is that any reader can read any card and obtain basic info on the card.

What make them different is the high-level application protocol spoken by the card. Each application (GSM SIM, banking cards (EMV), telephone cards, etc...) defines such a protocol. To give an example a GSM operator will buy a module (see [2] for an example of a manufacturer) and write the custom software that runs on it. If the software speaks the GSM SIM protocol, you have a SIM card. Of course the same chip can support several protocols at the same time.

A card needs some software that speaks one of these protocols. In principle you can write this software yourself, thus giving you total flexibility. The most common languages for this are C, assembly and java. Of course devising a message protocol, writing the software on the card and on the reader is a huge undertaking and is rarely needed.

In the case of crypto applications, there already is a relevant application standard (ISO/IEC 7816-8). All you have to do is buy a card that follows this standard (it will include crypto hardware and the necessary software). See [3] for an example. You then use a standard API (PKCS11/PC/SC) on the computer linked to the reader to communicate with the card.

This API gives you access to the crypto primitives offered by the card (store key, generate key pair, encrypt, decrypt). You can also store arbitrary data on the card, although storage is usually severely limited. Using the API, you can build a variety of authentication schemes, including schemes using PINs. Although to come back to your particular example, I wouldn't worry about keys leaking from the card. They really are secure. This API allows you to give smartcard support to custom applications. Note that many apps (like firefox for example) already have this support.

On linux there is a project ([4]) that provides an implementation of PKCS11 along with drivers for a variety of cards and card readers. They also offer some ready-made applications built on top of it, like PAM integration for example. Morana (talk) 07:22, 17 April 2008 (UTC)

Wow, thanks for sharing your knowledge. They way you described the application and protocols finally answered what makes a smart card a SIM card, or a bank card, or whatever, which I've been wondering about for the last fews days. I have some more questions, if you would be so kind:

• I understand the some smart cards can perform cryptological functions on board, such as generating keys and using those keys to sign or encrypt data. Does that mean that to encrypt or sign a chunk of data, it must all pass through the card smart card? That seems secure, but if it's a large amount of data, wouldn't the speed and communication channel bandwidth depend entirely on the smart card's capabilities?

For encryption, a combination of symmetric and public key cryptography is usually used. i.e. to encrypt an email you first generate a random key ($k_{t}$), encrypt the email with $k_{t}$ using a symmetric cipher, encrypt $k_{t}$ with the public key and attach the encrypted key to the message. When decrypting, you first decrypt $k_{t}$ with the private key then decrypt the message with $k_{t}$ using the symmetric cipher. The smartcard is only used to decrypt the symmetric key, which is only a few bytes long.

Cool, that makes a lot more sense. Similar to how full drive encryption encrypts a secondary key with your private key/passphrase so if you want to change your key or passphrase, you don't have to decrypt and re-encrypt the entire drive, just the secondary key. -- Eric —Preceding unsigned comment added by 70.2.178.61 (talk) 20:16, 17 April 2008 (UTC)

For signing, a hash of the message is taken, encrypted with the private key and attached to the message. To check the signature, the encrypted hash is decrypted using the public key. A hash of the received message is computed and the two hashes are compared. If they match, the message has not been altered and the signature is valid. The smartcard only has to encrypt the hash (also only a few bytes long). Morana (talk) 10:02, 17 April 2008 (UTC)

• I know the smart card modules have a lot of tamper-resistant designs and engineering put in to them, but I've also read about many ways with enough motivation and resources (we're talking NSA level) how to defeat most of them. I don't want to seem paranoid, but that's why I was wondering if private keys are actually encrypted with a PIN-passphrase not stored anywhere on the card.

Thanks again! -- Eric 66.75.102.95 (talk) 08:11, 17 April 2008 (UTC)

Office transfer

When I bought a new DakTech computer in 2005, I also bought Microsoft Office 2003 Professional (student discount :-) and installed it, and have used it since; I still have the installation CDs. Since this computer is failing somewhat, I bought a new computer this month: an HP with Vista. My ideal is to install Office on the HP before uninstalling it on the DakTech, since I always have schoolwork that needs to be done in Office. What procedure do I have to follow? Say, do I have to get a new installation code or something like that? I don't remember anything of the process for installation from three years ago, except that I used the installation CDs. Nyttend (talk) 13:36, 16 April 2008 (UTC)

Install it using the instructions that came with it. Use the installation code that came with the disks. If it fails (license in use), you will get a phone number you can call. Call and explain that you are removing it from one PC and putting it on anther. You will be asked if you are definitely removing it from the old computer. Say yes and you'll get the license activated for the new computer. -- kainaw™ 15:17, 16 April 2008 (UTC)

Software Configuration Management Tools - A Matrex for Comparing Vendors' Products?

Can you find a 'Product Comparison Matrex' of major Software Configuration Management Tools so I can easily see strengths/weaknesses of the various products?Ckdavis (talk) 16:31, 16 April 2008 (UTC)Keith

See Comparison of revision control software. -- kainaw™ 19:19, 16 April 2008 (UTC)

And, in case you want to try a search engine, I should point out that it's spelled "matrix". Google, however, may very well fix your spelling for you. StuRat (talk) 15:43, 17 April 2008 (UTC)

Thanks for the terrific find, User:Kainaw. --Ckdavis (talk) 15:50, 17 April 2008 (UTC)

Virus activated by a phone call?

In the season three of the TV series 24, Nina Myers tricks Jack Bauer into dialing a phone number and entering a series of number after the ring tone (I think it was the busy signal, but she tells him not to hang up and keep entering the numbers). It activates a computer virus in the CTU system which Myers had secretly implanted. I wonder if such a thing is actually possible in the current technology or was just a sci-fi prop. --BorgQueen (talk) 17:06, 16 April 2008 (UTC)

Reproducing that effect is indeed technically possible. In fact, the virus has to be already in the system, activated (but lying benign) and running to monitor incoming calls. Once the call from a pre-defined number arrives, or an activation code entered, the virus starts its destructive behavior. --soum ^talk 17:30, 16 April 2008 (UTC)

That's very interesting. Thanks for the reply. --BorgQueen (talk) 19:25, 16 April 2008 (UTC)

I guess the phone's planted to a modem of some sort, and the malware app is so coded that it can activate on ring. The virus had to be planted in the system.

Codasyl database

An academic database maintains different information about:students departments, courses, and tutors. Each student assigned to a particular course and has one tutor. A tutor for a number of students to tutees. Each course operates in one of the 5 departments within the college. And each department runs many courses. The system also records previous qualifications obtained by students. Question: a)Draw a Codasyl Schema to reflect the information held in the academic database. b)Draw a diagram to illustrate an owner and its member records in the academic database.Halaangel (talk) 19:54, 16 April 2008 (UTC)

Answer 1) Take the time to read the information at the top of the page which states that we will NOT do your homework for you, 2) Representation of this concept: RDeditors + Homework <> Success --LarryMac | Talk 20:16, 16 April 2008 (UTC)

Codasyl? Yikes your school is... old school. Good luck! --90.209.36.146 (talk) 20:25, 16 April 2008 (UTC)

Registry

Hi

I deleted some unuseful keys from the registry editor, I deleted them this way,by clicking on the key and from the edit menu I chose delete, but the next day they showed up again. Can someone please help me how to delete them temporary.

Thanks

T Cauchi —Preceding unsigned comment added by 195.158.126.187 (talk) 21:19, 16 April 2008 (UTC)

Deleting random keys from the Registry editor is a bad idea. As for how they came back, some program you use (or Windows itself) is putting them back. Which probably means they aren't as "unuseful" as you think they are. If you meddle with your registry enough, you can completely crash Windows. Don't do it! --Captain Ref Desk (talk) 00:19, 17 April 2008 (UTC)

If you absolutely, positively, at the penalty of death, need to find out what program is modifying the registry keys, you can use something like Process Monitor, but the Good Captain is correct, stay out of the registry! 83.250.207.154 (talk) 06:45, 17 April 2008 (UTC)

April 17

e-mail etiquette

As I am new at e-mailing, some friends have suggested I read up on e-mail etiquette. But I don't know where to find out about this subject. —Preceding unsigned comment added by 66.153.67.219 (talk) 02:25, 17 April 2008 (UTC)

You can find out by searching Google. Here's a good link: http://www.emailreplies.com/ ~EdGl (talk) 04:22, 17 April 2008 (UTC)

I had some guidelines about email when I joined my company. Basically, it came down to: Don't put anything in an email that you wouldn't put in a letter, and watch who you send it to. Just remember that an email can be easily forwarded to someone else without your knowledge or consent. However, that doesn't mean that you need to be very formal. Oh, and lastly, just because the email software lets you create sparkling letters and purple backgrounds, that doesn't mean it is a good idea to actually use it (unless you are an 8-year-old girl sending out birthday invites). Astronaut (talk) 12:07, 17 April 2008 (UTC)

There is an unresolved argument about the proper way to reply: Above or below the text. You MUST include the text sent to you. Otherwise, the person may have no idea what you are replying to. I feel that replying above the text is best. Most people don't want to scroll down to see your reply. They want your reply at the top - easily visible. Others feel it should be below the text because that is how it was done before email.

I second the argument against colors, pictures, animations, and sounds in email. Adding anything other than plain text to your email makes it look like you were typing it up at a pretend tea party on your Little Princess plastic table with help from your My Little Pony. When given the option, select "plain text" as the format for your email. You can add to this a few more rules:

• Never forward anything that people haven't asked for. That photo, joke, or animation is not really that funny. Bill Gates is not giving anything away. Disney will not send you free tickets. You are not going to win any lottery.
• Never attach more than one photo to an email (unless you know how to shrink the FILE SIZE of the images). Nobody cares enough about you to wait three days for the email to load.
• Never click on Reply to All when you are replying to one person - especially when your only message is "Why did I get this?"

OK. Don't get me started. I could be here all day harping about the idiocy of people in this workplace alone. -- kainaw™ 12:30, 17 April 2008 (UTC)

The Jargon File recommends bottom-posting, i.e. putting replies below quoted relevant parts of the original message. 89.76.165.87 (talk) 14:16, 17 April 2008 (UTC)

Where I work, people seem to have the mistaken idea that shipping around an Excel spreadsheet or a 13MB Word document is the equivalent of "communication". For myself (like other replies above), I prefer plain text in the common vernacular. And remember, "brevity is the soul of wit" so be terse, but not too terse. -- Atlant (talk) 13:31, 17 April 2008 (UTC)

What really annoys me is the opposite. If you need a document that is fine, but some people just send an attached word document containing a few lines of text. The usual culprits are secretaries sending messages on behalf of high-level managers, I suppose they just work in word all the time. I would also agree with the above comment about avoiding unnecessary colours.

That actually was my point. I frequently get mail messages that have an empty body, but have a Microsoft file attached to them. As if I want to open Word to read "Come to my very important meeting." or "Here, look at these three screen-shots of my Excel spreadsheet." The other situation is the Excel spreadsheet itself, where apparently I'm supposed to divine the meaning that the sender is trying to convey amidst all those rows and columns.

Atlant (talk) 16:50, 17 April 2008 (UTC)

I would also add make sure your email is relevant to everyone concerned. Recently in our organisation an email asking for the person who stole a chocolate bar to ensure it was replaced in the lunch break. This was sent to everyone. One of the many responses pointed out that people in London were unlikely to travel to Leeds (200 miles) to take a chocolate bar. -- Q Chris (talk) 14:37, 17 April 2008 (UTC)

Yes, but if the evil fiend is ever discovered he might well be sent to Coventry. StuRat (talk) 15:31, 17 April 2008 (UTC)

I also find people using e-mail like it's a bulletin board. Offers of free puppies, solicitations to buy girl scout cookies, etc., really don't belong on e-mail at work. I suppose I can stand some personal matters, though, like setting up a birthday party for a coworker. StuRat (talk) 15:31, 17 April 2008 (UTC)

And, while formality is not required, I'd avoid writing like you talk: "Are y'all comin to da confrance then ya gonna go ta da staff meetin ?". StuRat (talk) 15:35, 17 April 2008 (UTC)

Since I like work with like a lot of like doctors and stuff, you would like think that like there was a certain like word that they wouldn't like use over and like over when they like send a like email. I bet you like can't guess what that like word would like be - like can you? -- kainaw™ 17:06, 17 April 2008 (UTC)

Whatever that word is, I'm sure it's totally tubular. StuRat (talk) 03:48, 18 April 2008 (UTC)

zOmg!! u mus avod txt spk. (Translation: Don't use mobile text abbreviations - it makes you sound like an idiot). C U l8r. Astronaut (talk) 10:23, 18 April 2008 (UTC)

Another bone of contention is upper and lower case letters. Some people type emails as though their keyboard doesn't have a Shift key (DYSWIDT?). In informal emails between friends this may be just about tolerable, but it should never be done in the work environment. --Richardrj ^{talk email} 11:15, 18 April 2008 (UTC)

Animated Pictures and Sounds

Hi, I've been playing around with imageready and I was wondering if I could get a picture (like a .gif) to react to mouse rollovers and clicks by animating, is it possible to also make it react by playing sounds? —Preceding unsigned comment added by 24.76.248.193 (talk) 05:09, 17 April 2008 (UTC)

I think you'd need some kind of script or html. You certainly can't do it with a *.gif. George D. Watson (Dendodge).Talk^Help 07:47, 17 April 2008 (UTC)

You need something like Adobe Flash to do the things you mentioned. Although it can probably be done using Java script and other software as well. - X201 (talk) 10:14, 17 April 2008 (UTC)

It is possible to do this with CSS. First, you have to make the image the background or border of a link (because IE is flaky when the :hover is applied to anything but the "a" tag). Now, for the a, set the static gif. For the a:hover, set the animated gif. You can do sounds in CSS on :hover. All in all, I think using JavaScript will be a better solution. -- kainaw™ 12:22, 17 April 2008 (UTC)

Javascript or CSS can do this. Don't know about getting ImageReady to export it automatically, though, but it's probably possible. I feel obliged to note that having sounds triggered on a mouse rollover on an image is a terrible idea in general, though. --140.247.248.34 (talk) 16:41, 17 April 2008 (UTC)

Linux related disk management

Suppose I have 4 disk partitions, and I'm going to fill the three partitions with different linux distros. Could I make the 4th partition into /home directory for the three distros? If it's possible could you gave me links to page on how to do that. Thanks in advance. roscoe_x (talk) 13:17, 17 April 2008 (UTC)

Yes. It is not complicated. First, you need to ensure that all three distros have a format they can use. Most likely, it will be ext3. Install the first one and set /home to be the 4th partition in ext3. Install the second one and do the same. It will probably format the /home partition again. Install the third one. It will likely format the 4th partition yet again. Now, when you boot, all three will see /home as expected. -- kainaw™ 13:21, 17 April 2008 (UTC)

There's the added complication of all three distros wanting to set up the boot sector for themselves. You'll have to be careful with that. If you're familiar enough with Linux to get the boot loader to do what you want, then you're probably able to work with the /etc/fstab file, too. I'd install the first one with a /home, the second and third without. Then I'd add a line to the /etc/fstab on the other two so that they're also using the same one. --Mdwyer (talk) 22:43, 17 April 2008 (UTC)

One thing to watch out for is user IDs — if you want to have the same username and home directory for all three distros, you'd better make sure that username maps to the same numeric user ID in all cases. Otherwise you may find that you're not allowed to access your own home directory. If the distros you're installing are similar enough, they just might all assign the same numeric UID to the first user account created, but you may not be that lucky — for example, Debian-based distros will number "real" user accounts starting from 1000, while Red Hat-based distros will apparently start from 500 and some others from 400 or even 100. Thus, while poking around /etc/fstab, you may also need to edit /etc/passwd, and possibly also /etc/shadow and /etc/group. (Hint: It's probably best to choose a user ID that exceeds UID_MIN for all the distros you're installing.) —Ilmari Karonen (talk) 23:57, 17 April 2008 (UTC)

webcam driver

Is there any webcam vendor that release their driver's source code? Or maybe a popular webcam brand that has open source driver. Thanks in advance. roscoe_x (talk) 13:19, 17 April 2008 (UTC)

There's a guy in France who has written Linux drivers that support over 200 webcams. I don't know of any open source Windows drivers. --LarryMac | Talk 14:00, 17 April 2008 (UTC)

Turning link color

After visiting a Wikipedia link, that link changes color from blue to purple on my computer screen. This is related to browsing history. Is there a way to change the colors of the links on Category:Non-article Agriculture pages as the appear on my computer screen without having to visit each of the links? Thanks. GregManninLB (talk) 15:10, 17 April 2008 (UTC)

You could set the "unvisited link color" preference in your web browser, or you could edit your personal wikipedia style settings to change just that page's colors. If you add the following text:

addOnloadHook(function () {
  if (document.title == "Category:Non-article Agriculture pages - Wikipedia, the free encyclopedia")
      for (var i = 0; i < document.links.length; i++)
          document.links[i].style.color = "orange"
})

to the end of the following page: monobook.js, it will do what you want (assuming you want all links on only that page to be orange, which might not be the case). --Sean 16:09, 17 April 2008 (UTC)

Hi Sean. Here is a more detailed explaination of what I am looking for. After visiting a Wikipedia link, that link changes color from blue to purple on my computer screen. To tag pages with categories, I've been opening all the pages at Category:NA-Class articles, for example, to turn the links purple. Then I use the All pages with prefix. Those pages for which the link still is blue need a Category:NA-Class category tag. It takes a lot of time to initially open all the pages within a particular category to turn the link from blue to purple. Is there a way to change the colors of the links in Category:NA-Class articles as the appear on my computer screen without having to visit each of the links? I tried editing my temporary internet file (browser history) and tried using the 'Print all linked documents' option of windows print feature to printing to a file (that I then deleted). I wasn't able to edit my temporary internet file (browser history) and the 'Print all linked documents' option didn't result in making the category links purple. Can you create me a script that causes all the links on a page (e.g. Category:NA-Class articles) to change color to show that I visited the page (without actually opening the linked page)? I am open to other methods as well. Thanks. GregManninLB (talk) 16:30, 17 April 2008 (UTC)

Hmm. You're really getting into bot territory with those requirements. Perhaps if you asked at Wikipedia:Bot requests someone could write up an "add category-na tag to all articles starting with 'non-article ...'" bot. It could also just list the ones you want to remain blue in your scheme, for you to add them by hand. It shouldn't be difficult, and this kind of drudgery is definitely work for a machine. --Sean 19:06, 17 April 2008 (UTC)

Internet Explorer proxy scripts

Is there a script/boot options I can configure internet explorer with which will enter in a username and password automatically when internet explorer is opened each time? Ty. Tomayres (talk) 15:26, 17 April 2008 (UTC)

Downloading a file with Firefox

When I download a file, such as a Word document or Excel spreadsheet, with Firefox, the default behaviour seems to be to save the file to the desktop. The preferences allow me to change the location to which the file is saved, but don't seem to allow me to change the behaviour itself. I would prefer that the file be immediately opened in the relevant application. Is there a preference setting that allows this? Many thanks. --Richardrj ^{talk email} 15:40, 17 April 2008 (UTC)

When I click on a link to a word document in Firefox, I get a dialogue box asking me whether I want to open or save. If you don't get this dialogue, it might be because you've clicked through it before with the 'do this automatically for files like this' button checked. If so, your decision can be modified at tools/options/content/file types/manage. Algebraist 16:25, 17 April 2008 (UTC)

If you are using that fruity operating system, it is Firefox > Preferences >> Content >>> Manage There you can change the behavior for each filetype as Algebraist said. Kushal 18:47, 17 April 2008 (UTC)

Yeah, I had a look at that (I'm using Windows XP), but it didn't help. Clicking 'Manage' brings up a box called 'Download actions', but the box is empty, so I haven't created any rules. Ah well, never mind. --Richardrj ^{talk email} 07:54, 18 April 2008 (UTC)

Are you left- or right-clicking on the file? Left-clicking should pop-up the dialog box that User:Algebraist mentions, which only allows you to save or open, it does not allow you to change the save destination, unless you have modified the default behavior on the options/main dialog. If you right-click and select "save link as", then you can select the destination, but can't choose to open the file after. --LarryMac | Talk 14:08, 18 April 2008 (UTC)

is iBook's 'boot into "target" disk mode' possible only for firewire or USB too?

So I read iBooks have a "target" disk mode you can boot into where they just ack like a dumb hard drive and you can connect them with a cable to another ("host") computer which will just see it as a connected external hard-drive...

so, two questions....

1... could this work with USB too or only firewire?

2... could my windows pc be the host?

thank you.

1. No (only firewire), 2. No (only other Macs). SEE BELOW. I don't know exactly why but I do know that the Target Disk Mode is something that is hard-coded into the logic board of the Mac (it isn't software) and as such is pretty inflexible (which makes sense, given that its main purpose is to work even if the software components on the drive have totally failed). --Captain Ref Desk (talk) 20:30, 17 April 2008 (UTC)

thank you for your prompt and complete answer to both of my questions! —Preceding unsigned comment added by 79.122.24.31 (talk) 11:07, 18 April 2008 (UTC)

Extending Captain Ref Desk's comments a bit, I think saying "no" to the second question isn't quite correct/complete. Any FireWire-equipped computer that supports FireWire disks should be able to connect to a Mac running in Target Disk Mode. But whether or not that computer can access the "disk" is another question. Mac disks are typically formatted in HFS Plus (with some older ones being formatted in UFS. Most Windows PCs won't be able to access those disks without additional software. But if they had such software, then Target Disk Mode should work with them as well. Captain Ref Desk, do you agree? NB: In the near future, Apple also promises support for ZFS.

Atlant (talk) 15:53, 18 April 2008 (UTC)

OK, I've looked into it further and I revise my above answer. Your Windows PC could be the host, provided it has 1. a firewire port, and 2. third party utilities for accessing HFS+ formatted drives (like MacDrive). --Captain Ref Desk (talk) 00:33, 19 April 2008 (UTC)

I-Scream MP3 players

Hi; I saw one of these on the HMV website but I can't seem to trace either reviews of it, or the company's web-page. Am I missing something, and can anyone offer any advice? Thanks! —TreasuryTag—t—c 20:14, 17 April 2008 (UTC)

I was able to track down the company - SOSMP3. I can not find much else at all, except this single mention on Yahoo Answers (Ireland & UK version). For what it's worth, the domain is registered to the FJRP Partnership in Sutton, GB. I get the impression that "I-Scream" is a house brand for HMV, but I have no direct knowledge of that, it's just a feeling. --LarryMac | Talk 00:54, 18 April 2008 (UTC)

H-809A MP4 Player

I have purchased an H-809A MP4 player, and it works well so far, but I want to know who makes it so I can update the firmware later if necessary.

Or, even better, I'd like to know how it works so I can create my own firmware, as there are several user-interface problems I'd like to fix.

Does anyone have any information of this kind? --Zemyla^t 20:55, 17 April 2008 (UTC)

Well, if you want to create something yourself, why not take a look at ... um ... Rockbox? Kushal 02:18, 18 April 2008 (UTC)

Averaging Dates in Excel

I have two columns, each with over 800 dates. Column B has a list of start dates, such as 4/17/06, and column C has a list of end dates, such as 5/20/08. I need find the average time taken between start dates and end dates. Ultimately, I need to say, "For all 800 entries, the avarage completion time is x months and x days."

131.194.79.108 (talk) 20:56, 17 April 2008 (UTC)

Typing the equation =B1-A1 into cell C1 should give the completion time in days. Select cell C1 and drag the blob on the bottom-right of the cell to copy the equation to all of column C. --h2g2bob (talk) 22:07, 17 April 2008 (UTC)

Note that you will probably need to specify that the final form is a "Number" (Cell > Format) not a Date (it'll otherwise assume the final number is a date code serial number, which is not the case!). --Captain Ref Desk (talk) 01:16, 18 April 2008 (UTC)

You can also take the average of each range and subtract the two averages:

${\frac {\sum _{i=1}^{n}(b_{i}-a_{i})}{n}}$

what you want

is average(b - a)

${\frac {\sum _{i=1}^{n}b_{i}-\sum _{i=1}^{n}a_{i}}{n}}$

addition is associative

${\frac {\sum _{i=1}^{n}b_{i}}{n}}-{\frac {\sum _{i=1}^{n}a_{i}}{n}}$

division is distributive

is average(b) - average(a)

--Random832 (contribs) 16:10, 18 April 2008 (UTC)

I was considering posting that advice re. associativity (ideally it could be done in a single cell), but I realized Excel dates might not add very well. The differences used to get a duration rather than a date might be essential in this case. --Prestidigitator (talk) 18:19, 18 April 2008 (UTC)

April 18

Is wireless encryption secure from other users?

Hi, I know that unsecured wi-fi traffic is unsecure because anyone with a wireless card can sniff all the data you are sending and receiving. If I am on a secured wi-fi network, but there are others who are allowed to use the same network (they know the shared encryption key needed to access the network), can they read my data? Thanks, --131.215.166.106 (talk) 00:05, 18 April 2008 (UTC)

If you use such encryption as WEP, then you aren't secure from anyone, as it's easily crackable.

If you use WEP or WPA, then other users have the same key, and so they can see the traffic. (It's symmetric encryption: if one has the key, you can't prevent him to use it.)

To be secure, you need to use such encryption programs as PGP/GnuPG (for e-mail), or encrypted protocols like SSL (HTTPS) or SSH.

--grawity ^{talk / PGP} 11:50, 18 April 2008 (UTC)

It's not necessarily as simple as that. WPA uses TKIP, which creates new keys for each user and session (and indeed, each packet), which would mean that it is not as simple as using the same WPA key to decode every packer. Our article on TKIP is a little fuzzy on the subject, but it says that if you use a pre-shared key, the session base-key will always be the same; but I'm not so sure that's true. I mean, it would be trivial (well, ok, not trivial, but fairly easy) to add something like a Diffie-Hellman key exchange to generate a new completely new key each session for each user, so I find it highly suspect that the bad-boys who designed WPA would overlook such an obvious problem (with an equally obvious solution). Does anyone know the exact details of this? --Oskar 14:08, 18 April 2008 (UTC)

With due respect, I believe the question at hand isn't being addressed. A http://en.wikipedia.org/wiki/LAN grossly simplifying, works on the idea that everyone on its network shouts to it, and that it shouts to everyone on its network. "People" - computers - just ignore things that aren't relevant to them. Or, if there were a classroom, Jenny shouting she loves Jeremy is ignored by Tom, Dick, and Harry; presumably this request generates a response from Jeremy. This is not different for wi-fi, except that the classroom now isn't bound by physical wires between the "desks", to go with the metaphor. Now for your actual question - "securing" a wifi network (and the above responders' comments about security here are relevant) just mean that someone has to say the magic word before wireless treats them like they're in the "classroom." Once they are, again, everyone is shouting everything to everyone, so dad can have a traffic monitor and know you're visiting badcowsandthekittenswholovethem.example.com.

So, short answer: Directly and immediately, yes.

Is there Orthodox Islam?

Question moved to Humanities Desk.

Sony NWZS515B

I'm contemplating buying this MP3 player, but can't seem to find any mains chargers that are definitely compatible with it. Could someone direct me to one, preferably on Amazon UK? Thanks. —TreasuryTag—t—c 07:26, 18 April 2008 (UTC)

The product is available on Amazon.co.uk. The details indicate that the battery is rechargeable but no mains charger is provided. Presumably, that means that it is recharged through the included USB cable. So if you just leave it connected to your computer, it will charge itself. If you really want a mains charger, how about one of these (results of a search for "USB charger"), which provide a powered USB port directly from the mains supply or the lighter socket in your car. Most/all of these are "market place" sellers, but there are probably plenty of other suppliers with proper shops/warehouses in the internet. Astronaut (talk) 09:27, 18 April 2008 (UTC)

Thanks for that; do you think the type you listed would work... as in, not damage the player, be too low voltage/ampage or whatever? I definitely need a mains one - I'm on a trip to the Israeli desert where USB ports are in short supply!! —TreasuryTag—t—c 09:33, 18 April 2008 (UTC)

My neice has a Sansa MP3 player and the charger is just like one of those. She has had no problems. The USB specification says 5V is all that should be supplied across pins 1 and 4 (see our USB article) - I imagine that you could test any charger to see if it does that and only that. However, what I've said is no guarantee. Perhaps it would be better to try Sony's website to see if they sell a charger or you could ask their tech support. Astronaut (talk) 09:46, 18 April 2008 (UTC)

"what I've said is no guarantee"... Oh, no, I'm holding you fully responsible :-) No, thanks, good advice! —TreasuryTag—t—c 09:50, 18 April 2008 (UTC)

Installing OS from a USB

Just wondering if it would be possible to install an OS from a USB (i.e. the installation files are on the USB) and if anyone has any good links/advice. I ask because my DVD drive is not working. This is probably not easy, and i figure the first thing to do would be to create a boot disk. Next I'd have to somehow get the OS installation CD onto the USB. Then, prior to re-booting, i'd have to set the USB to load first, and go from there... am i on the right track?

Appreciate the help.

Yes, you're on the right track. Here's a tutorial on installing Windows Vista from USB, I'm sure there are other tutorials out there for Linux, etc. You won't need a boot disk if your BIOS supports booting from USB (I hear most new ones do). Good luck! Xenon⁵⁴ 10:36, 18 April 2008 (UTC)

See http://www.pendrivelinux.com/2007/01/01/usb-knoppix-510/. --212.149.216.233 (talk) 11:01, 18 April 2008 (UTC)

Here's a guide for Windows XP.--droptone (talk) 11:33, 18 April 2008 (UTC)

How to course on designing html websites

How to course on designing html websites I'm not too tech savvy but I would like to learn how to create html websites to promote the nationalist agenda. So far the only sites I know how to create are message boards, blogs, and pre-designed websites. But I've never made a website where I've actually designed the layout myself. Are there any good introductory websites that teach you how?--Gary123 (talk) 13:03, 18 April 2008 (UTC)

I don't know about web sites, but HTML for Dummies is a good book: [5]. StuRat (talk) 19:47, 18 April 2008 (UTC)

You should start by learning some HTML. In the beginning, you only need to know a few elements: paragraph, heading, image tag and link. Most of the necessary functionality of web page can be done with these four elements (but don't forget to add a title). However, the most important are the contents. Contents is the reason why people will come to your web site. You could start by writing the text as plain text with a text editor. The HTML coding and CSS formatting can be added later. --PauliKL (talk) 11:24, 19 April 2008 (UTC)

Getting different results from hash-programs

I was idling and doing nothing in particular just now, and by chance I happened upon this page that details how you can commit your user to a specific hash (which I think sounds like a very good idea), and in there I read something I didn't know: that there comes a whole lot of hash-functions with GNU core utils (which I guess is pretty obvious when you think about it, seeing as how the OS needs to hash passwords and such). "How nice", I thought, "let's try it out!". So I typed "echo "" | sha512sum" into the command line, and it did indeed spit out a hash. However, when I compared it to the list of reference hashes on wikipedia, I saw that it had hashed to a different value. I found this most strange, and on a whim I typed in "sha512" instead (instead of "sha512sum", that is), knowing that ubuntu helpfully informs you about packages you need to execute programs you don't have yet. Ubuntu recommended the package "hashalot", and I installed it, and unlike "sha512sum", the newly installed package did indeed give the right hash.

What's going on here? I mean, why does the standard GNU program give a different hash than the "hashalot" program? Does it do something else, except just creating SHA-512 hashes? Does it add a salt, or something? I assume that the other program was the more accurate one, because it gives the same value as wikipedia does. Can someone enlighten me? --Oskar 13:47, 18 April 2008 (UTC)

When you do

echo "" | sha512sum

you're not calculating SHA512(""), you're calculating SHA512("\n"), because "echo" outputs a newline. Try:

sha512sum < /dev/null

and see what happens. -- Coneslayer (talk) 13:52, 18 April 2008 (UTC)

Ahh! I figured it would be something silly like that! Thank you! --Oskar 14:03, 18 April 2008 (UTC)

With GNU's echo, you can say 'echo -n "" | sha512sum' to suppress the newline that echo usually tacks on. --Sean 18:29, 18 April 2008 (UTC)

Snes Emulator editor

does anyone know of a good site where i can find one of those?the juggresurection ^IstKrieg! 13:49, 18 April 2008 (UTC)

ehrm... www.znes.com - best SNES-emulator nowdays...

Well..while im in the area...

I was trying to install Linux on a computer that had been wiped clean. When i got to the hard drive partitioner, the box to select hard drives was empty. Is there something i need to do beforehand?the juggresurection ^IstKrieg! 14:20, 18 April 2008 (UTC)

I hate to stoop to the dead obvious, but exactly how wiped clean is it? Are you sure there's still a hard drive in there at all, and that it is still physically connected? Also, this might be stretching a bit, but you might want to do some research on SATA support in Linux. I think most new distributions/versions should handle SATA drives cleanly (though I recall there being some kind of issue with RAID). It might be worth a little searching. --Prestidigitator (talk) 18:58, 18 April 2008 (UTC)

well, and youre probably going to think im an idiot for this, but me and a friend tried to get it open to see if it was phisically connected. We worked at it for an hour and could not get it open. No screws, no holes, no sliding covers, NOTHING. he had never seen anything like it in the time that he has been fixing computers.the juggresurection ^IstKrieg! 19:51, 18 April 2008 (UTC)

One of those Chinese puzzle boxes, huh? What is it? Dell? Gateway? Sounds like an HP to me. If you can give us the make/model, there is a high chance that someone has opened one before. -- kainaw™ 02:34, 19 April 2008 (UTC)

Another computer changing question

Now that I have Office installed (see questions from 16 April), I'm setting up other features of Vista, including Windows Mail. Rather than checking email on the server, I download my email to Outlook Express on my old computer. Is there any way to transfer my emails en masse to the new computer? The only ways I can think of are (1) forward all of them to myself and download them onto Windows Mail, or (2) find them on the old computer's hard drive and copy them with my flash drive to the new one. Can I simply move them over, so that the emails from the old computer look as if they had been sent from the new one? Nyttend (talk) 14:38, 18 April 2008 (UTC)

It looks like this page is describing what you want to do. --LarryMac | Talk 15:11, 18 April 2008 (UTC)

Thanks, but one question: it seems like the page is describing migrating on a single computer. Do you think I could migrate through a flash drive onto another computer? Nyttend (talk) 16:04, 18 April 2008 (UTC)

Sure. Each of the first three steps (exporting addresses, accounts, mail) involves selecting a storage location for the file(s) to be written, so just select a folder on your flash drive. When you get to the import steps, select the appropriate folder on the flash drive and Bob's your uncle. --LarryMac | Talk 16:09, 18 April 2008 (UTC)

When I migrated to Vista, I found Windows Mail was able to import the .dbx files from Outlook Express without problems. I copied the .dbx files from my old PC (somewhere like C:\...\Application Data\Identities\{...}\Microsoft\Outlook Express\*.dbx) onto a CD, popped that CD into my new PC, and chose "import" on the file menu in Windows Mail. Very easy and quick enough. Also did the same for the Contacts.

In case you're interested, I was using Windows Mail as a route to import my mail into Outlook 2007 on my new PC. I'm still baffled why Outlook cannot read the .dbx files without them being linked to Outlook Express or Windows Mail.

Astronaut (talk) 17:00, 19 April 2008 (UTC)

Overclocking

I have been working on overclocking, but found it difficult to locate good sources for the article. Could anyone recommend some? Online sources are preferred but published books are welcome too. Thanks. --BorgQueen (talk) 16:08, 18 April 2008 (UTC)

A decent article came with my XFX card, let me know on my talk page how I should send the PDF file to you. Sandman30s (talk) 17:02, 19 April 2008 (UTC)

Google Groups won't let me post

I've subscribed to this group in order to ask a question, but Google Groups won't let me post. I've tried to post my message about 10 times, but it doesn't show up, and "My groups" keeps saying I have no recent activity. Am I missing something? --Lazar Taxon (talk) 16:13, 18 April 2008 (UTC)

How recently did you post? This is a Usenet group, which is very different from a web forum. Your post may not show up for days! -- Kesh (talk) 00:45, 19 April 2008 (UTC)

In my experience, articles posted through Google Groups show up almost immediately in GG. (Of course, they take longer to propagate to other Usenet servers.) Do you get an error message when you try to post? AndrewWTaylor (talk) 20:38, 19 April 2008 (UTC)

SATA transfer mode

I have a WDC WD1600JS-60MHB1 hard drive (that's how Windows reports it), on Serial ATA. In Device Manager > IDE ATA/ATAPI Controllers > NVIDIA nForce4 Serial ATA Controller > Primary Channel > Master Drive, the Transfer mode is set to "Serial ATA Generation 1". Would selecting "Serial ATA Generation 2" make it faster? If yes, is it safe to select it? --grawity ^{talk / PGP} 19:36, 18 April 2008 (UTC)

Yes, your drive is a SATA Generation 2, so it would be advisable to select that option. Whether it will run faster or not - highly unlikely or at most negligibly - read the SATA article for theoretical limits and limits of mechanical devices such as hard drives. Sandman30s (talk) 16:59, 19 April 2008 (UTC)

April 19

going away for a few weeks but i'd like access to my windows pc, any freeware to do that?

my wife is staying home and the computer will often be on. i think it's behind some firewalls or something, I want it to actively poll and initiate a session to me so i can use a remote desktop somhow...is there any way to do anything like that? basically, it would be the same thing as 'back doors' a hacker would install except that I want to do it myself, but prefereably so no one else can connect too. :) thank you for any advice you might have.

Windows comes with a Remote Desktop client built in. Google "Windows Remote Desktop" and you'll find info on how to set it up (e.g. here). --Captain Ref Desk (talk) 00:25, 19 April 2008 (UTC)

I'm not entirely sure about a 100% freeware version, but I know that Kim Komando generally offers a 60-day free trial of GoToMyPC.com during the commercials in her shows – with a promo code. crassic!^[talk] 01:46, 19 April 2008 (UTC)

VNC is free and easy to use. My favorite was TightVNC, which allows you to see your remote computer (in this case, your home computer) in a VNC client or a web browser. Other VNC clients probably have similar functionality. Besides the browser option, there are VNC clients for non-Windows computers as well. As for firewalls, you will need to find an open port for VNC to broadcast on (VNC's defaults are 5800 and 5900). ShieldsUP (scroll down that page) is a quick way to identify your open ports. / edg ☺ ☭ 02:12, 19 April 2008 (UTC)

You can use a free service called LogMeIn . It provides you with some advanced features such as chatting with the host and file transfer as add-on premium services, but the basic desktop sharing is free. 12:35, 19 April 2008 (GMT +0400)

code

What have I done wrong here?Failed to parse (PNG conversion failed; check for correct installation of latex, dvips, gs, and convert): \iiiint_{\delta\gamma}^{\hat\mathbf{H}i}\ \mathrm{d}x=\oint_{\pi^i}^{{e^-i}^x^2}\ \mathrm{d}\overrightarrow{\phi} Zrs 12 (talk) 01:39, 19 April 2008 (UTC)

See this for help. Basically, you probably don't have the required programs. -- kainaw™ 02:32, 19 April 2008 (UTC)

Actually, the parse error is caused by the {{e^-i}^x^2} part which needs some more braces for grouping. The ^ operator is nonassociative, so you can't say a^b^c; you need to specify a^{b^c} or {a^b}^c

By adding braces around x^2 I get this:

$\iiiint _{\delta \gamma }^{{\hat {\mathbf {H} }}i}\ \mathrm {d} x=\oint _{\pi ^{i}}^{{e^{-}i}^{x^{2}}}\ \mathrm {d} {\overrightarrow {\phi }}$

which may not be right (I have no idea what it means) but at least it passes the parser. --tcsetattr (talk / contribs) 03:09, 19 April 2008 (UTC)

I don't know what it means either. I was just messing around in the sandbox. Zrs 12 (talk) 15:01, 19 April 2008 (UTC)

Blogger and Adsense

I've just started a blog and I saw that you can have advertising on your blog through a service called Adsense and that they'll let you wet your beak in some of their revenues. So, I pushed the appropriate buttons and received an email asking me to send through a form specifying how any payments should be made. There the problems began. The Google Adsense account form only shows fields for residential addresses. It also mandates that a contact phone number be provided. I do all my business through a PO box address for security reasons. If someone was going to post me a cheque I'd surely want it to go to a secure address. Further, I'm not all that mad about sending off my home address or any phone number to Google. I can't think of any speck of a legitimate reason why they need either. They have all the controls in their hands already: why do they need personal data? The "help service" on their site just takes you in circles on this one. Can anyone enlighten me here? Is there way around this? Retarius | Talk 03:33, 19 April 2008 (UTC)

Without specifically addressing all of your concerns, I can say that after four years of blogging I've not received a penny from adsense, so unless you have a blog that draws tons of visitors (and/or visitors who click links), then setting up adsense is probably a waste of time. --LarryMac | Talk 05:44, 19 April 2008 (UTC)

C/C++/Java/WhatHaveYou prefix/postfix increment

Even after many years I'm still sifting through countless examples of people using postfix (not sure if that's the right term) increment or decrement when it's not necessary. Is there some kind of psychological reason why people insist on saying "i++" instead of "++i" when they don't intend to use the old value?

I can understand some underlying reasons to prefer prefix. Like when your C++ compiler doesn't do, or has disabled, optimizations, or when your class overloads the operation a la "MyClass& operator++()" vs "MyClass operator++(int) const". Java is beyond me (I don't know much about the runtime optimizer). I have even less faith in a JavaScript implementation's ability to optimize-out unused return-values. Where did this abundance for postfix increment start?

Pet peeve, comment at will :) --Silvaran (talk) 07:52, 19 April 2008 (UTC)

I just think that it's an aesthetic thing, I personally think "++i" just looks strange. It's probably a case that i++ is more widely used because it's more widely used, i.e. since that's what most people see i++ when they read other people's code, they type it themselves. Optimizing on the level of "i++" or "++i" is honestly a little silly, I mean what are we talking about here, something on the order of one cycle? Unless you are writing for MIX, who the hell really cares? 83.250.207.154 (talk) 09:06, 19 April 2008 (UTC)

Maybe people see the name "C++" as an endorsement of this style. Personally I used to write "i++" because it looked more consistent with "i += 2", but I switched to "++i" because of the issue with iterators. Any modern C compiler will compile "++i" and "i++" into exactly the same code when they appear in a void context, probably even when all optimizations are disabled (yes: I just checked this with gcc and VC++). I suspect this was already true of the earliest K&R implementation. This also goes for C++ when "i" has a builtin type. I assume it's also true of Java and JavaScript and every other language that has this idiom. -- BenRG (talk) 12:57, 19 April 2008 (UTC)

Are you suggesting a pre-fix operator is faster than a post-fix operator? I can't imagine why it would be. Maybe it's just personal preference, but ++i just looks weird to me, so much so that I will sometimes change it to i++ unless the context demands the pre-fix operator. My other pet peeves that make code harder to read and maintain: putting the "{" at the end of a line instead of putting it on its own line; too     much      spacing      between      operators; poor indenting; and so on. Astronaut (talk) 15:04, 19 April 2008 (UTC)

Yes, the prefix operators can be faster. The postfix operator requires that the value of the variable be captured, the variable incremented, and then the old captured value used. This probably isn't a big deal for built-in types, but when the operator is overridden, it can become more of an issue (especially because keeping similar semantics for user-defined types can often mean the difference between returning a reference to the original instance vs. making a temporary copy of the object). I personally don't have an aesthetic preference, so I have built the habit of using the prefix operator any time I don't really need the old value. --Prestidigitator (talk) 17:46, 19 April 2008 (UTC)

Postfix is taught before and more often then prefix. Also, linguistically, I would hazard a guess that x++ functions more places then ++x does. I know a few interpreted languages for which neither has any actual significance (besides saving the bother of typing x = x + 1), which only support the latter syntax. 72.192.247.233 (talk) 03:01, 20 April 2008 (UTC)

Looking for a nice, high-quality, free midi synthesizer

I have a whole lot of MIDI files. They used to sound rather nice with my old offboard sound card. On my new computer, they sound terrible (like midis should, they say). Are there any free, high-quality midi synthesizers out there I could use? I used to have Wingroove around, and it would install itself as a MIDI playback driver. I was looking for something like that... — Kieff | Talk 07:57, 19 April 2008 (UTC)

Assuming you use windows - check that your MIDI player is configured to use Microsoft GS Wave-table Synth - I found that it has a surprisinly decent quality. Your MIDI player might have defaulted to a sucky synth-set with bad samples that comes with your sound card. Something else to check - certain MIDI files created with a "General Midi" (GM) device such as a Roland won't sound that great with GS so you might have to switch synth-sets; however I've found this to be an exception rather than a rule. Sandman30s (talk) 16:50, 19 April 2008 (UTC)

If your new computer has Vista, check for updated Vista drivers for the soundcard. I have read that some soundcard drivers have not yet been updated for Vista, so only the default drivers end up being used. Astronaut (talk) 17:20, 19 April 2008 (UTC)

web-based MRI file viewer

Is there a web-based way to view 3D MRI scans? Something like MRIcro but able to be run off of a browser client? Just curious... --98.217.8.46 (talk) 13:01, 19 April 2008 (UTC)

Boot Camp Keyboard

When I use Boot Camp to run Vista, (-_-) my keyboard suddenly doesn't work! It can eject disks, but no typing. How can i fix this to make the keyboard work again? --Randoman412 (talk) 15:01, 19 April 2008 (UTC)

Don't run Vista. Useight (talk) 16:21, 19 April 2008 (UTC)

Hardly a helpful response. Astronaut (talk) 16:50, 19 April 2008 (UTC)

A less helpful response. Useight (talk) 19:44, 19 April 2008 (UTC)

Never mind, now the keyboard works. (P.S. i don't want to run Vista either, anyone have an XP disk? (I'm Kidding)) --Randoman412 (talk) 19:24, 19 April 2008 (UTC)

TigerDirect has WindowsXP Pro for $139.99. Useight (talk) 19:44, 19 April 2008 (UTC)

Camera behind video display

The problem with talking and using a webcam is that both parties can't look at each other's image and directly into the webcam at the same time (if they don't look directly at the webcam, their eyes appear to be averted from you). Is there a technology that would allow the camera to go behind the screen? ----Seans Potato Business 15:53, 19 April 2008 (UTC)

Professional studios use angled glass so that presenters can read the autocue and look right down the lens of the camera at the same time. I guess you could rig something similar - angled glass in front of the screen, the webcam to one side, above or below, and a darkened room or hood to cut down on stray reflections - but it sounds like a whole load of trouble to go through. Astronaut (talk) 16:48, 19 April 2008 (UTC)

Random rebooting

Hi, my single-core P4 computer has suddenly, for the last two weeks, developed the habit of rebooting randomly straight into POST (bypassing even a blue screen) - I'm using XP SP2. It reboots only when I am using a graphics intensive application such as a movie or game, and only after a random amount of time - minutes or hours. I've done a thorough virus and spyware check, and done various burn-in tests, and checked the windows system events but since these are clean 'resets' they don't even register in Windows. I've also upgraded my nvidia to the latest, then reverted to 162. I've reinstalled DirectX. Any other ideas please? Sandman30s (talk) 16:43, 19 April 2008 (UTC)

This is one of the most difficult computer problems to solve. However, the process is simple:

1. Get a new power supply. If you have a 300W, get a 500W. If you have a 500W, get a 700W. Just get more power capability in your system.
2. If that doesn't fix it, disconnect everything that isn't necessary: CD drive, floppy drive, second hard drive, sound card, network card, second/third stick of RAM...
   • If that fixes it, put it back in one part at a time until you figure out what is causing the problem.
3. If that doesn't fix it, get new RAM.
4. If that doesn't fix it, get a new video card.
5. If that doesn't fix it, get a new hard drive (copying your system from the old one to the new one).
6. If that doesn't fix it, get a new motherboard and CPU.
7. If that doesn't fix it, get a new case.

I had to go all the way to the last step once. The case itself was causing hard drive corruption and random rebooting. Like I said, it is a difficult problem, but a simply process of elimination. -- kainaw™ 18:13, 19 April 2008 (UTC)

Sigh - all these 'get new' scenarios are not only costly, it will mean sourcing older components. I was thinking about getting a whole new computer anyway, so spending more on a four-year old system might not be wise. So you think it's unlikely to be a software or hardware problem with the graphics card - since it reboots ONLY when using graphics intensive apps? Sandman30s (talk) 21:08, 19 April 2008 (UTC)

The case was causing the problem with the hard drive? The only problem I can forsee a case causing is poor airflow. Or maybe a short. Useight (talk) 19:42, 19 April 2008 (UTC)

And even if it were the case - how would you diagnose that? Tell us the full story, Kainaw! --90.209.36.146 (talk) 20:45, 19 April 2008 (UTC)

I put the new power supply on top because that is the most likely culprit. Video cards suck a lot of juice and if you are maxing out the hard drive while maxing out the video card, you are asking for a drop in power to the point that the computer loses power and reboots.

I usually think it could be a fan (overheat) issue. However, I've never found that to be the problem. You can try replacing the fans if you like.

As for the case... this is a VERY weird problem. I was asked to fix a computer that constantly got hard drive corruption. I replaced the drive - still got corrupted. I replaced the drive (again) and cables. Still got corruption. I removed everything but the essentials. Still got corruption. I swapped out everything (motherboard, power supply, and all drives). Still got corruption. I put the owner's original parts in a new case. No corruption. I asked the owner if ANYTHING at all happened before this problem. He said that he cleaned out the dust inside the case. Is that all? He said there was a lot of hair from his cat. Is that all? He said he removed a little sheet of aluminum foil... That wasn't aluminum foil. It was lead foil that sat between the case speaker and the hard drive chassis. Without it, the magnet on the back of the speaker was so close to the hard drive that it was causing random drive corruption. -- kainaw™ 21:16, 19 April 2008 (UTC)

Thanks for all the insight Kainaw. I'm not so sure about the power supply since it's been running like that for years. The overheating might just be the problem - maybe I can test that by placing a room fan next to the open case - sounds silly but it does cool things down! Sandra reports my hard drive as running too hot. My 7900GS is showing 58 degrees celcius. BTW would you recommend 400W power supply for a powered 7900 GS, two SATA drives and a dvd writer? Sandman30s (talk) 21:36, 19 April 2008 (UTC)

OK, I've cooled it down with a fan and it still reboots. Tried again and it seems to be getting worse - rebooted after 1 minute of watching a movie. My system monitor shows the system fan to be at 0 RPM - however I can physically see the system fan spinning so I'm not sure if a sensor is down or something. I hope it's not the video card as that is likely out of warranty. Ugh. Sandman30s (talk) 22:51, 19 April 2008 (UTC)

All 400W PSUs aren't the same. You need to consider the number of amps that can be supplied on each of the rails. After problems with cheaper units, I use a Thermaltake Toughpower and whatever problem it was that I was having at that time went away. --Seans Potato Business 06:59, 20 April 2008 (UTC)

gaming

i recently downloaded the demo to the strategy game caeser 4 from its official site. there were no problems during the download and installation but now everytime i click the icon the computer restarts and a disc check occurs and a message box says that the computer has recovered from a serious error . HELP --scoobydoo (talk) 16:58, 19 April 2008 (UTC)

Looks like the game is causing the computer to crash. The disk check, "serious error" message stuff is usual for crashes. Do all the usual checks for viruses and spyware, make sure you have the latest updates, etc. Check the game's forums (if any). Find out if the same problem exists on another computer. But best advice: don't run that game again. Astronaut (talk) 17:15, 19 April 2008 (UTC)

Error Messages

On Windows XP, how do you set it to show unabridged error messages? Zrs 12 (talk) 19:59, 19 April 2008 (UTC)

Is that possible? Can you give a specific situation that you'd like that to happen? Gary King (talk) 20:24, 19 April 2008 (UTC)

It is possible (see http://www.andybrain.com/qna/wp-content/uploads/2007/10/strange-error-1.jpg), but I'm not sure that's on the XP OS, although it is obviously on some Windows OS. And I have not a specific situation, all situations would be good though. Zrs 12 (talk) 20:37, 19 April 2008 (UTC)

usb hard drive not giving itself a drive letter

I was installed ubuntu the other day and accidentally chose to install it on my usb drive which was plugged in and happens to have same hard disk space as my regular drive. soooo...I caught my mistake "in time" and didn't put ubuntu on the usb drive, but the formatting was all ready to go and it may have half-completed is my guess.

So now I'm back on my windows XP pro OS (same machine). I plug in the USB and everything goes like clockwork, "USB detected" "maxtor x.x..x found" "mass storage device detected" etc. the drivers are in the fine, it's clearly communicating, but when I go to "My Computer" it hasn't assigned itself to a drive letter....so I don't know how to access it.

Like I said, I'd reason to guess that I screwed up the formatting just enough to not be able to access to reformat it and make it right. I'd like to recover the data (futurama backups) but no big deal if I can't. Any ideas for ubuntu or xp to fix this? Thanks.

It is probably formatted in ext3 - which Windows won't assign a drive letter to. I avoid Windows as much as possible, so this is from memory. Click start-run. Type compmgmt.msc. Go to diskmanagment. You should see the drive and be able to format it to a Windows typed drive. If those commands are not exactly correct, perhaps the next person here will know the proper spelling. -- kainaw™ 21:21, 19 April 2008 (UTC)

That will work, but it's faster to run diskmgmt.msc, which opens the disk manager directly. -- BenRG (talk) 22:27, 19 April 2008 (UTC)

fascinating! Thank you both

Javascript image preloader

I've written up a web app that needs to be able to load a number of images before it lets the user view the page. (No, this isn't a regular website or anything; it's a very specific web app that will only be used by one person. So don't lecture me on web design! ;-)

The site uses PHP and Javascript together. I have all of the image paths dumped into the HEAD of the HTML in an array like the following:

var doc_tag = new Array();
doc_full[1]="152509.pdf.full-0.png";
doc_small[1]="152509.pdf.thumb-0.png";
(etc.)

On the page itself, I have a DIV that sits on top of everything else and says "Loading..." The goal is to preload all of the images and then remove the "Loading" DIV only then. So in the ONLOAD of the BODY element of the page, I call a function called precache() which is the following:

function precache() {
	var preload = new Array();
	for(i=1;i<doc_small.length;i++) {
		preload[i] = new Image();
		preload[i].onLoad=imageLoaded();
		preload[i].src = thumb_dir+"/"+doc_small[i];
	}
}

Which seems like the usual way the web says to preload things. The "onLoad" function of the preload images then does the following:

function imageLoaded() {
	preload_count++;
	document.getElementById("cachestatus").innerHTML = "Thumbnail "+preload_count+" of "+(doc_small.length-1);
	if(preload_count>=doc_small.length-1) {
		hideloading();
	}
}

"Cachestatus" is just a little SPAN on my "Loading" DIV. preload_count is a global variable. hideloading() is just a function that hides the "Loading" DIV.

Now all of this seems like it should work to me, but it don't. 1. the "cachestatus" SPAN never updates, 2. the page is displayed before all of the images have preloaded. Usually MOST of the images have preloaded but clearly not all of them.

So... what am I doing wrong? Any thoughts? Better way to do it? --Captain Ref Desk (talk) 20:49, 19 April 2008 (UTC)

The more I play with it, the more I get the picture that Firefox (and Safari) trigger the onLoad event of the Image object long before it actually loads the image. (I've tried reversing the order of the SRC assignment and the ONLOAD assignment; it changes nothing). Thoughts? It certainly seems irregular/incorrect. --Captain Ref Desk (talk) 02:59, 20 April 2008 (UTC)

April 20

Don't Think that Digital Data will Last Forever

It's pretty frustrating and disappointing after I read this article Coming Soon: A Digital Dark Age?. (see also Digital Dark Age) I thought digital way is the best and perfect way to preserve data. However, it turns out I was wrong. Hardware and software are evolving so quickly such that they are not compatible to each other in terms of time. It seems open-source software is a solution on the software side. But there seems to be no virtual machine can emulate all kinds of out-of-date hardware. All digitals are gone after 17 years according to the article. - Justin545 (talk) 00:28, 20 April 2008 (UTC)

Please see XML and consider that the last iterations of digital media have been the Compact Disc then the DVD and now the Blu-Ray. Even predecessor media - Floppy disc - had a magnetic circular disc media. While it's true a similar leap in fundamental media is not only possible, but suggested by current technological trends (Solid-state drive and Quantum computing among others ). Ultimately, you should turn to the example set by Ozymandius. (Post script - if one of the regulars would be so kind as to truncate my links, I would appreciate the edit) 72.192.247.233 (talk) 02:53, 20 April 2008 (UTC)

Wikified links as requested. Astronaut (talk) 03:26, 20 April 2008 (UTC)

Do you, um, have a question? In any case, 17 years sounds unlikely to me, personally, and I don't think things are going to be quite as dire. The historical examples they bring up are not so much about different hardware as they are about different consumer models—yes, the hardware changed a LOT in the last 20 years, but more importantly the people who were USING the hardware changed a lot. NASA can't get its old data but that's not really because the machine is out of date, it's because it was on a machine that even at the time a relatively small subset of people knew how to use and operate, so there's a lot less existing infrastructure in place to recover that knowledge, and nobody has been ushering it along to new machines, new formats, etc. as standards changed. As computers have penetrated all aspects of individual life (for those in the West, in particular), though, the incentive for keeping it easy to read legacy formats goes up exponentially as well. Standards change and evolve, but if the incentive is there it is easy to convert formats or maintain legacy issue. It's very telling, as well, that virtual machines can emulate pretty much any out-of-date hardware that had real commercial viability at one point. No, we can't emulate the Harvard Mark I, but we can do Commodore 64 without a hitch. The sheer number of computers produced today insures that it probably won't be too hard to emulate (if not actually run) old hardware in the future. --Captain Ref Desk (talk) 02:58, 20 April 2008 (UTC)

C# Syntax

I've been trying to learn some C# and came across this puzzling bit of syntax:

 System.IO.DirectoryInfo dir=new System.IO.DirectoryInfo(@"C:\");
 foreach (System.IO.FileInfo file in dir.GetFiles("*.*"))
 {
 ...

What is the purpose of the "@" before the string, and why is it not needed in the next line? Astronaut (talk) 02:39, 20 April 2008 (UTC)

Google gave me an answer: What does an @ before the start of a string literal mean? — Kieff | Talk 05:48, 20 April 2008 (UTC)

Visual Studio 2008 Express

Can I use a version control system (preferably a free one such as CVS) with Visual Studio 2008 Express? If so, how is it integrated with the Visual Studio IDE? Astronaut (talk) 02:46, 20 April 2008 (UTC)

Mozilla Thunderbird -- Top-Quoting Possible?

Hello,

I would like to know if there is a way to force Thunderbird to top-quote when replying to emails. I understand that it's not the best email form, but my work place requires it.

Thank you for any help,

--Grey1618 (talk) 10:19, 20 April 2008 (UTC)