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September 5

How to make this?

I want to make this: http://btewiki.org/index.php?title=File:BTE_Power_diagram_260_MW.jpg but I have no idea what program that can make that 202.137.25.53 (talk) 04:34, 5 September 2013 (UTC)

It's just a simple 2D image? You could use Paint, or Inkscape, or Powerpoint, or innumerable other free or paid graphics design programs. DrewHeath (talk) 05:43, 5 September 2013 (UTC)

Well, it's easiest to use specialized diagramming software for things like that, but there are lots of such programs. Our article on diagramming software lists some of them. Microsoft Visio is probably the most widely used, since it comes with Office -- but that diagram doesn't quite have a "Visio" feel to me. Looie496 (talk) 06:08, 5 September 2013 (UTC)

However, the learning curve with such a program might make it quicker to do a one-off diagram using Paint or some other more manual software which you already know. StuRat (talk) 06:27, 5 September 2013 (UTC)

Depressingly, I draw roughly similar diagrams in PowerPoint (for commercial projects) and in Keynote (for scientific presentations and teaching). If the diagram is large, the design simple, and there is a somewhat structured textual description, I might use Graphviz, especially for repetitive tasks. --Stephan Schulz (talk) 12:42, 5 September 2013 (UTC)

You could even use lines and text boxes in Microsoft Word to create the diagram as a page, then save the image. I'm not recommending Word, because it's not designed for graphics, but it can be done. Dbfirs 14:07, 5 September 2013 (UTC)

My personal favourite is Paint.NET. --.Yellow1996.^(ЬMИED¡) 02:10, 6 September 2013 (UTC)

Paint (XP edition) is the One True paint program! PaintXP FTW! The newer Paint looks to me like some kind of Paint For Slow Kids, so mostly a GUI issue.

It's not difficult to draw these things. Start with the "text in a box" tool, then draw the actual boxes, and finally connect them using either the "thick line" tool or the rectangle tool depending on the quality of your mouse and your skill. It is a bit of work but not really difficult. - ¡Ouch! (^{hurt me} / _{more pain}) 06:41, 6 September 2013 (UTC)

I agree, Windows XP paint is quite good. I hesitated to make the switch (er... well I was on Vista but the paint isn't much different on here fom XP) but what made me do it in the end was transparent backgrounds and layers. --.Yellow1996.^(ЬMИED¡) 03:05, 7 September 2013 (UTC)

OTOH, Paint.net looks much richer than plain Paint, and they ironed a lot of the bugs out. - ¡Ouch! (^{hurt me} / _{more pain}) 09:05, 6 September 2013 (UTC)

So now the bugs are flat and devoid of wrinkles ? StuRat (talk) 10:57, 6 September 2013 (UTC)

Exactly. They take up more space now but at least they look a little more presentable. ;) --.Yellow1996.^(ЬMИED¡) 03:05, 7 September 2013 (UTC)

Run linux command in series of directories, save output in table

If I have such a command like:

find . *.pdf | wc

and I want to run it to count how many pdfs I have in each directory and output the result in a table like

dir1: 4 pdfs
dir2: 3 pdfs.

How can I do it? OsmanRF34 (talk) 18:28, 5 September 2013 (UTC)

Here's a not very clever way of doing it and it probably won't work if there are spaces anywhere in the path

find . -name "*.pdf" -exec dirname '{}' \; > /tmp/junk
for f in `sort -u /tmp/junk` ; do echo -en "$f \t"; grep -c $f /tmp/junk; done

--TrogWoolley (talk) 19:03, 5 September 2013 (UTC)

Here's an alternative method that avoids a temp file:

   find . -name "*.pdf" | perl -MFile::Basename -lane'$j{dirname($_)}++;END{print "$_: $j{$_}" foreach sort keys %j;}'

--Mark viking (talk) 22:55, 5 September 2013 (UTC)

Any of these should work:

find -name \*.pdf | rev | cut -d/ -f2- | rev | uniq -c
find -name \*.pdf -printf %h\\n | uniq -c
find -name \*.pdf -execdir pwd \; | uniq -c

These of course fail for files with newlines; one might be able to fix the middle one by using uniq -z, but I'm not sure. --Tardis (talk) 05:25, 9 September 2013 (UTC)

September 6

Secure Deletion Methods

I've read various articles on this subject and there seems to be a lot of disagreement over what is and isn't sufficient to securely wipe a hard drive. Some say one pass with random data is sufficient to make the previous information on the hard drive completely unrecoverable. Though others suggest this isn't enough alone and a 3-pass or 7-pass method is necessary (though most agree the 35-pass method is way overkill). And supposedly, if the article on the subject is to be believed, Bradley Manning's (single pass) zero-filled drive had its data recovered, so that seems to be an insecure method if true.

I suppose my question here is: Assuming I had the necessary and expensive modern hardware, how feasible would it be to retrieve a meaningful amount of overwritten data from a hard drive that has been filled with a single pass of pseudo-random data? -Amordea (talk) 05:12, 6 September 2013 (UTC)

An interesting query. The relevant WP page is Data recovery#Overwritten data. It appears that we need to know whether we are talking about a 'standard' magnetic type Hard disk drive(HDD) or a Solid-state drive (SSD) as it is relevant as to how easy it is to recover overwritten data. A scientific paper by Peter Gutmann on how recovery might be achieved is Secure Deletion of Data from Magnetic and Solid-State Memory USENIX Security Symposium Proceedings, San Jose, California, July 22-25, 1996. Possibly rather out of date by now! --220 of ^Borg 05:42, 6 September 2013 (UTC)

In my mind, I was automatically thinking of a magnetic hard drive. But I am interested to know what would be effective for an SSD as well. -Amordea (talk) 06:17, 6 September 2013 (UTC)

On old 1980s style magnetic media, it was easy to write data between tracks, and relatively easy to recover data that had been overwritten (even several times on the same machine). I recall being able to read overwritten data on a floppy disk just by moving it to a drive with a different head alignment. Modern media has tracks so close together that there is much less opportunity for residual data to remain, and I would be happy with a single complete overwriting for any of the confidential data that I've held (though I did once smash a hard drive with a sledge hammer). The problem is in persuading the operating system to overwrite every track and sector, that's why specialist software is used that bypasses the operating system. In Bradley Manning's case, I think it was unallocated sectors that held the recovered data. Although normal specialist equipment cannot recover data that has genuinely been overwritten (preferably with random data, not just zeros), computer forensics at the leading edge of technology might have techniques that could detect some residual magnetism from previous writes, even after several overwrites. This would involve removing the disk from the drive in a clean room and remounting it so that it could be read by microscopic detectors at molecular level, much smaller than the original write heads. This would cost many tens of thousands of pounds, and success seems unlikely to me, because the magnetism comes in discrete units, but I'm not au fait with modern computer forensics. Most recovery is from sectors that just didn't get overwritten. Have we any experts? (I expect that the true experts are sworn to secrecy!) ... later note Apologies to 220 of Borg, I wrote the above before reading the excellent linked article by Peter Gutmann. His methods obviously worked well with 1990s media densities, but he does say that they are unlikely to work with modern media. Dbfirs 07:40, 6 September 2013 (UTC)

As for the Bradley Manning article, I'm skeptical of the line that says it could be retrieved: "The operating system had been re-installed in January 2010, and on or around January 31, 2010, an attempt had been made to erase the hard drive by doing a "zero-fill," which involves overwriting material with zeroes. The material had been overwritten only once, which meant it could be retrieved.[46]" I wonder if the original source is more nuanced in its description. That line probably needs to be reviewed more carefully. Shadowjams (talk) 08:53, 6 September 2013 (UTC)

Yeah, I admit some skepticism there too (if you couldn't tell from the language of my original post). The Wired article it pulls that information from isn't much more helpful, saying more or less the same thing, but even that is second-hand information. We have no idea the full context of what the computer forensics experts had to say about how they recovered the data and I've never read anywhere else that zero-filling is insecure for file shredding. -Amordea (talk) 09:28, 6 September 2013 (UTC)

Does anyone know if any of the data from her hard drive was actually used as evidence during the court martial? If it was then it demonstrates that it was definitely recoverable. I don't have a name (talk) 12:37, 6 September 2013 (UTC)

As I explained at length here Talk:United States v. Manning#Source doesn't say material was recovered from overwritten space, I don't think the Wired article actually says what our article says although I agree it's confusing. I thought I changed both articles so either I made a mistake or someone changed the main article back. Either way I've changed our article back to what IMO the Wired article actually says. Note that the fact evidence may have been used at her trial doesn't tell us anything about whether it was recovered from overwritten space as it remains unclear whether the entire hard drive was zerofilled (and the relevance of 'unallocated space' is unclear if it was, does it mean an OS was reinstalled and they could only recover data which hadn't been subsequently overwritten so perhaps two passes were enough?). I would hope at the trial precisely how and from what the data was recovered would have been discussed in more depth whether under examination or cross-examination but if all we have is similar to what we have at the moment, it still won't help us. As for the general question, this has been discussed at length before on the RD and so far no one has presented evidence it's actually possible (as in someone has actually done it) to recover data on a HD which has been overwritten. Our article was the first time I'd ever even heard a claim, but then on reading the Wired article I realised what actually happened is unclear and IMO there remains no evidence that anyone has ever demonstrated recovery from actual overwritten data. Nil Einne (talk) 14:51, 6 September 2013 (UTC)

Okay I did a search on the transcripts from [1] and the Wired article is worse than I thought (whether this is Wired's fault or the information presented pretrial was just misleading I don't know. Take a look at [2] particularly page 53. The investigator actually says "Nothing can be recovered prior to 25 January, nothing in unallocated space can be prior to 31 January" (if you read earlier you'll understand the dates, the whole drive was zerofilled on 25 January when the OS was installed and free space was zerofilled on 31 January).

So basically even the investigator is saying you can't recover anything. However a seven pass was used for the free space, not a single pass. (As I mentioned in the article talk page, erasing only the free space is somewhat risky in that it's often difficult to ensure all the free space was erased although I believe in OS X it's an OS option which may reduce the risk, although there is also stuff like technically non free space such as tiny files where some unwanted info may reside. However from what I saw, there's nothing that complicated here and it's perhaps not that surprising.)

Of course this doesn't tell us whether the investigator could have recovered everything if only one pass was used. (I don't know what option was used during OS install my guess would be a single pass which could mean anything allocated would have been written at least twice once for the zero file and once when it was written.) But there's definitely nothing in this trial that I've seen suggesting it is possible.

There was some early discussion about how secure erase was overwriting and no mention of how many times or the number of passes being relevant. Another cancelled attempt to erase free space was done in February and there is some brief discussion of stuff being wiped in the first 2 minutes but there's no suggestion that anything could be recovered if it had only been overwritten once, although the investigator also doesn't point out that comparing it to the 3h40min for the 7 pass would be misleading since a single pass would be enough. They were mostly going by what they saw on the logs so probably weren't thinking that carefully. Much later there's also brief mention of zeroing HDs and data being lost during military upgrades although I presume the military always does more than one pass anyway. (In any case, if you really could recover data from overwritten sectors, you'd need atomic force microscopy or something so I presume someone other than the forensic investigator mentioned would need to be involved.) All in all, this transcript seems to mostly support what I've heard before namely if it really is possible to recover data that's been really overwritten (as opposed to believed to have been overwritten but not actually) even only one time, forensic investigators aren't talking about it or using it in court cases. (Of course even if any of this were possible and the US government may have been willing to reveal they could do so, it seems it wasn't necessary in this case and despite all the hype I'm not convinced they cared enough to reveal such information even if the case hinged on it.)

The case does ilustrate two things. Number one, as I said before it's probably more beneficial to do a single pass erase of the whole disk than to do a multiple pass erase of a portion of it. Number two, there's no point doing any erase, multiple pass or single, if you're just going to rewrite the same incriminating data (okay to be fair I'm not sure it was the same data, the previous data may have been worse). (And funnily enough a secure container which was never broken was created the same day of the abandoned erase attempt in February. Maybe if the secure container had been diligently used and the erase attempt completely there would have been much less evidence at least from that computer.)

Nil Einne (talk) 15:43, 6 September 2013 (UTC)

Wow, this has been very informative. Thank you for the investigative legwork, Nil Einne. -Amordea (talk) 22:04, 6 September 2013 (UTC)

I thought I could keep this as a simple minor offside, but it seems I was wrong, hiding to avoid distracting from the main discussion, not to shut down discussion. Nil Einne (talk) 20:06, 6 September 2013 (UTC)

Somewhat offtopic While looking at the transcripts I noticed this [3]: “ So the military has a program where they'll take a green suiter, put us into a civilian corporation, and I had the luck of working at Microsoft in the place where they handle all of the zero day exploits that Microsoft works with, and a zero day exploit is something such as an exploit that they're no known patch for that vulnerability for yet and those are highly valuable. So the Microsoft security MSRC really taught me a lot how corporations deal with this threat of mallware or malicious software vunerabilities in their operating systems and how they respond to it and how about they triage it and how their teams handle it at the program manager level type of thing. ” Unspoken but obvious is why the military would be interested in having someone working with zero day Microsoft exploits... Nil Einne (talk) 15:59, 6 September 2013 (UTC) Because the United States Government owns and operates millions of computers, many running Microsoft Windows, and has a vested interest in knowing any vulnerabilities? Because there's an entire career track in the U.S. Army and other services that focuses entirely on making sure the information-technology operated on behalf of the American defense department remains secure? Because part of the Army career path for information technology specialists is to provide training that will be relevant in the civilian marketplace? The quote doesn't sound sinister to me. Nimur (talk) 17:45, 6 September 2013 (UTC) Sure the military is obviously interested in protecting their computers (and other computers important to the US government), nothing I said suggested otherwise (in fact I intended to say it but decided it was unnecessary particularly since this is offtopic and I always get TL;DR complaints but if you prefer that version so be it) but they are surely also interested in breaking computers used by other parties, and that know of zero day exploits before many other parties is clearly going to help. And who said anything about sinister? I said it was obvious, not sinister. The fact that the US military is going to be extremely interested in both exploiting zero day bugs and protecting themselves from them is as I was trying to say before you replied obvious and unsurprising, and this would be the same even before the Edward Snowden revelations. (And the fact Microsoft is quite willing to help them is similarly obvious not sinister and similarly the fact they clearly have a great advantage in this area over even nominal allies who have to hope it will be shared with them and not used against them, as further proven by the Edward Snowden stuff should be obvious not sinister.) What I didn't say because I thought it was obvious is that despite some weird denials or strange expressed belief that it wasn't happening by a variety of parties (particularly before the Edward Snowden stuff), there's strong evidence it's happening and it isn't even that hidden as this example I happened to come across shows, even if until recently rarely discussed in many cirles. (If you consider what's obviously happening implies something sinister, that's your business not mine.) I don't get the relevance of the other stuff, no one ever said the military wasn't interested in providing training relevant to the civilian marketplace and the wider commentary sort of implies that providing training (both for the civilian marketplace but also training from the civilian marketplace that they can bring back to the military). But there's no reason why that training would in particular be in working with Microsoft zeroday exploits. And to say it's just a coincidence that they have someone doing so as part of a wider programme to provide such training defies reality. (Although I'm not that sure you're actually trying to say that because you earlier acknowledged there were actually good reasons why they would want it even if only acknowledging one of the obvious ones. However I felt in my original comment I was clearly addressing the fact they had someone working with zeroday Microsoft exploits not that they had people working in the civilian marketplace in general so I don't really see that wider discussions on such programmes and what their general aims are is particularly useful to this discussion which I acknowledged two times now is offtopic. But of course being offtopic, I'm not going to complain if you want to initiate such discussions, it's just that it sounds like you aren't particularly interested in such discussions.) Nil Einne (talk) 19:37, 6 September 2013 (UTC)

I didn't find enough information regarding Recovery of overwritten drives, quite bizarre there are more articles about deleting than about recovering. 190.60.93.218 (talk) 17:30, 6 September 2013 (UTC)

Note as I've said in previous discussions and somewhat suggested in the main topic, that's good evidence no one is doing it, or at least if someone is it's very secretive not the sort of stuff you're likely to have to worry about unless you're a real terrorist or a foreign government or something similar. Nil Einne (talk) 19:56, 6 September 2013 (UTC)

Q from a firefox n00b

Somehow this morning, I clicked a wikipedia link and it appeared above the tabs. I noticed that and wanted to undo it, but the undo option was disabled (WTF? There IS not much a browser ever has to undo, how can it miss that obvious one?) And now I'm stuck with the W icon. Any idea how I can enable the undo feature and/or undo it without the heavy guns (System restore etc)? This is NOT on a rig which would get wiped anyway. :( Puzzled, - ¡Ouch! (^{hurt me} / _{more pain}) 06:09, 6 September 2013 (UTC)

By "above the tabs" do you mean in the Bookmark Toolbar? Thanks ツ Jenova20 ^(email) 09:07, 6 September 2013 (UTC)

What was the link you clicked? Can you upload a screenshot?--Shantavira|^{feed me} 15:51, 6 September 2013 (UTC)

RD/S, I clicked the tab and somehow dragged it. - ouch

Also, should we assume you have the latest version of Firefox? But back to the question, when you say it appeared above the tabs, do you mean that it was in its own window? Dismas|^(talk) 16:02, 6 September 2013 (UTC)

Not even close. I should have added that it is still 3.0.4. I don't like the new ones with their ginormous RAM footprints. Not a window. It appeared in a line betwen URL and tabs. - ouch

Sounds like you bookmarked a page and now it's in your bookmarks toolbar. Click the bookmark with your right mouse button and select "Delete" from the menu. Alternatively find the bookmarks menu and select "Show All Bookmarks", you can organize your bookmarks there. 88.112.41.6 (talk) 16:33, 6 September 2013 (UTC)

Show all bookmarks seems to work. Didn't try it before System Restore, :( - ouch

I agree with 88.112.41.6. You've just added it to your bookmarks toolbar by mistake, by inadvertently dragging the link into that region of the browser window. As mentioned above, just right-click and press "delete". --.Yellow1996.^(ЬMИED¡) 03:12, 7 September 2013 (UTC)

Thanks all. It was in the bookmarks line; I must have dragged a tab there somehow. Delete did not actually delete it; I had to use System Restore to get rid of it, which took an awfully long time. Virus scan didn't find anything else.

It's funny how a word processor, which has to process ~10,000 undoable actions (virtually anything that's not New/Load/Save/Print) does so flawlessly, but a browser, which usually doesn't encounter even one undoable action per hour, promptly fails.

I made another bookmark (not by dragging but by r-click and "add to bookmarks") and I could delete that one.

Resolved (or at least I hope so), thanks. - ¡Ouch! (^{hurt me} / _{more pain}) 15:55, 7 September 2013 (UTC)

Missing dll file

This screenshot shows a missing file on another laptop. Apparently it is causing all kinds of problems because it is missing. How to I get it and where do I install it? Would a virus somehow have destroyed it?--Doug Coldwell (talk) 19:45, 6 September 2013 (UTC)

This is intriguing. reader_sl.exe, the program which is throwing the error, is a helper app by Adobe designed to make their Adobe Reader program open quicker. mc_dec_dv100.dll, the broken file, seems to be by a company called MainConcept and is part of an audio decoder. And finally the whole thing seems to be going on in Google's appdata folder, which is where programs like Google Chrome are installed and where they store their user data.

It sounds like a possible Win32/Goblin infection. You could try using the tool on this page. I have not tested it. —Noiratsi (talk) 06:42, 7 September 2013 (UTC)

Collapsed information cut off on right

Hopefully this Teahouse question won't be archived. I couldn't see the text on the right when I clicked on "show". I asked about this thinking there was some glitch in how it was added to the page. User:PrimeHunter said there should be a scrollbar but there wasn't. He asked my browser, which is Internet Explorer 9.— Vchimpanzee · talk · contributions · 20:56, 6 September 2013 (UTC)

I see a scroll bar on my chrome browser. It should be at the very bottom of your screen, horizontally. If you don't see it, you may want to try Google Chrome, it's free. If you just want to read the information, I may be able to transcribe the entire thing for you. I don't know how else to help.--ɱ (talk) 21:23, 8 September 2013 (UTC)

I have no desire to change browsers. I have my reasons, and I tried Chrome on my uncle's computer anyway. I don't like it. For many reasons. And I don't have to. I don't see why this can't just work.— Vchimpanzee · talk · contributions · 17:18, 9 September 2013 (UTC)

I copied and pasted the information into an email to myself and I get a scrollbar that way. Or rather a picture of one. It is nonfunctional and I can't see what's cut off on the right. However, only that text which looks like the plain text on the edit screen is cut off. Once I send the email and look at it at the recipient address, things may be different.— Vchimpanzee · talk · contributions · 17:22, 9 September 2013 (UTC)

Incidentally, everything showed up when I clicked on "edit".— Vchimpanzee · talk · contributions · 20:27, 9 September 2013 (UTC)

Even if you don't like Chrome, I still recommend that you still update to a modern browser. You can get IE 11, which is available for Windows 7 computers, but when comparing functionality, there are many superior browsers.--ɱ (talk) 02:04, 11 September 2013 (UTC)

I don't like IE9. There's no way I would mess things up further. And I got my computer in 2008, so it does not have Windows 7 and I don't want it. As for the scrollbar, it worked in the email when I received it, though this is Firefox. Which I don't like. I'm just at this library because it's close and I feel more comfortable with web sites outside the select group here.— Vchimpanzee · talk · contributions · 14:49, 11 September 2013 (UTC)

September 7

Featured picture in the English Wikipedia

Are all the Featured picture in the English Wikipedia from Commons? --ديفيد عادل وهبة خليل 2 (talk) 09:39, 7 September 2013 (UTC)

Appears so. See WP:FP for more information. --.Yellow1996.^(ЬMИED¡) 18:41, 7 September 2013 (UTC)

Sound barrier

When i speak to my mother on skype she can hear my voice but not the loud music i'm playing on my computer. This defies logic to me. Can someone explain why this happens?Pass a Method talk 15:38, 7 September 2013 (UTC)

Well it's possible that you have some sort of background noice canceling software installed, but probably not since you're asking this. The other possibility (most likely) is that whatever mic you're using is really good at blocking out all noise other than the voice of the person talking to it. Is it a high end one? Do you have to talk very close to it (if it's a headset, this doesn't really apply)? Both? If so, that probably explains it. I'm not an expert, but these seems like logical reasons to me. --.Yellow1996.^(ЬMИED¡) 18:48, 7 September 2013 (UTC)

Speakerphones subtract what's playing through the speaker from the microphone signal so that you don't get an echo feedback loop. A lot of computers (at least laptops) do the same thing; it may even be Skype itself that does it. I suspect that if you used a different device to play the music it would be audible. -- BenRG (talk) 19:54, 7 September 2013 (UTC)

Elaborating on BenRG's response, the sound input device can use both digital and analog signal processing for noise cancellation. New computers often have multiple microphones and can use these for static or adaptive beamforming. The last time I tried to buy an audio-frequency input amplifier and ADC, I was not able to find one that didn't include multiple analog input channels and an on-board digital signal processor specifically aimed at the background noise cancellation problem. Moore's Law means more digital processing power is getting built in, by default, on even very analog-looking silicon like an audio microphone amplifier. Nimur (talk) 22:24, 7 September 2013 (UTC)

IRC client recommendation

Can anyone recommend to me a completely free IRC client for mac use? I would want one that is as simple as possible for a complete beginner (as I am). I don't know how to "compile" or anthing like that, so it has to be something that I can simply download a .dmg file and install. Thanks.--108.46.110.208 (talk) 20:44, 7 September 2013 (UTC)

We have a list of IRC clients sorted by operating system. If you're totally unfamiliar, start with ChatZilla (installation guide), Xchat, or Mibbit. Nimur (talk) 22:11, 7 September 2013 (UTC)

Thanks. I've downloaded chatzilla as an add-on to Firefox. Now I have to figure out using it:-)--108.46.110.208 (talk) 22:48, 7 September 2013 (UTC)

Because the controller of Xchat has apparently disappeared and no longer maintains Xchat's code, HexChat is considered to be the successor to Xchat. →Σσς. (Sigma) 23:59, 7 September 2013 (UTC)

I don't understand how that interfaces with my question. Is chatzilla something that runs "xchat", so I need to somehow switch to "hexchat"? (whatever either of those two are). I am a complete novice and totally unfamiliar with what you're talking about. You need to spoonfeed if I need to do something.--108.46.110.208 (talk) 00:08, 8 September 2013 (UTC)

Xchat (and hexchat) are alternative software options. If you are using ChatZilla and you're happy with ChatZilla, you don't need to download or use Xchat (or HexChat). User Sigma was merely informing you (and me) that one of the alternatives in my earlier recommendations might be out-of-date. Nimur (talk) 00:45, 8 September 2013 (UTC)

Thanks for the clarification Nimur!--108.46.110.208 (talk) 02:03, 8 September 2013 (UTC)

Follow-up question. So I've been playing around and reading some tutorials and I've got the hang of some of the rudimentary stuff. Here's an issue I haven't figured out how to get around. When I want to find a set of related specific channel, I've learned to search using a keyword. So, for example, in Dalnet, if you use /list *trivia* you get only rooms with trivia in their name or description. And for others you don't need the asterisks. But for others the search doesn't work; it ignores the attempt at a keyword and lists all channels (which is a painful scroll with servers that have a huge number of channels, though I learned you can abort with /cancel). So how do I navigate to find a set of rooms where the keyword doesn't work? Specifically, Freenode, does not understand this command, it just starts listing 7,000 channels, ignoring the keyword. How I would search channels at freenode? Thanks.--108.46.110.208 (talk) 02:03, 8 September 2013 (UTC)

A good IRC client (like HexChat!) does the channel description filtering for you. That way the server's own capabilities are irrelevant. DrewHeath (talk) 07:34, 9 September 2013 (UTC)

List of VARs and Systems Integrators calling on Small and Medium Businesses

Hi,

I am trying to find a list of computer hardware, software, and/or services VARs and systems integrators calling on small and medium sized businesses. I would like to start with the US by state, then expand into Europe, India and China. I have found definitions of the terms VAR and Systems Integrator but not a list of them. How do I search for companies which have these terms in their descriptions? Thanks! 216.188.230.33 (talk) 21:01, 7 September 2013 (UTC)

I Googled "pc system integrators", which led me to a Yahoo!7 search and a list here. Not specifically "Small and Medium Business" but it may help you narrow it down. Googling "pc system value added retailer" led to U.S. Computer Systems Value Added Resellers Companies. --220 of ^Borg 03:48, 8 September 2013 (UTC)

September 8

SEGA 32X/Saturn mod-combo

Is it possible to mod these two 32 bit systems together, like how the Genesis and CD are both 16 bit and compatible, just one cartridge-based and the other disk-based? I am mostly interested in having a joint system play a combined library, without so many wires, etc. It seemed odd that SEGA hooked up the 32X to the 16 bit systems instead of the more obvious 32 bit combo with Saturn. The SG-1000 had a floppy disk drive, and the Master System had one planned, so it made little sense to stop providing both formats for each generation of games released. I see that the Dreamcast has no cartridge equivalent, unlike the Saturn. Obviously, this is no different than the XBOX and Playstation, neither ever having cartridge formats. Look at this:

http://www.youtube.com/watch?v=UxoXNi_qCkQ — Preceding unsigned comment added by 184.43.123.234 (talk) 04:41, 8 September 2013 (UTC)

I don't do hardware mods, but I must chime in to say that is awesome! :) Reminds me of the Sega Neptune (more here) that Sega had planned but canceled. As for a 32X-Saturn combo, it can probably be done... if you know what you're doing (though it doesn't look like anyone has done this yet, either.) Hardware isn't my strong area so I wouldn't know how, though. --.Yellow1996.^(ЬMИED¡) 18:07, 8 September 2013 (UTC)

I was reading that when I wrote here on the Refdesk. I don't think many people are concerned with hardware mods of the disk-based systems, Saturn and Dreamcast. More people would rather emulate, it seems. It's funny, because the disks used to be a peripheral format, but now, there are only memory carts as peripherals. — Preceding unsigned comment added by 184.43.113.248 (talk) 01:56, 9 September 2013 (UTC)

Yeah. And even those carts are eventually going to be completely replaced by internal flash memory etc... perhaps even one day all saved files will be stored on some sort of "cloud"; personally, I prefer cartridges. They are a lot more robust, for one thing. And also they're nicer to look at all lined up if you're a collector! ;) --.Yellow1996.^(ЬMИED¡) 03:02, 9 September 2013 (UTC)

I suppose it would be impractical to mod the disk systems going technologically backwards, but I don't see why the 32X cartridge might not be modded into the memory cart slot of the 32 bit Saturn. It makes more sense than combining the 32X with the Genesis and CD, since the last two are 16 bit. For the Dreamcast, I could see the memory cart slot being used by an emulation program in a flash format, archived elsewhere in the "cloud." The post-industrial marketplace you are alluding to has been discussed here:

http://www.forbes.com/sites/johngaudiosi/2013/06/09/xbox-one-and-playstation-4-could-be-the-end-of-video-game-consoles/ — Preceding unsigned comment added by 184.43.118.168 (talk) 08:42, 10 September 2013 (UTC)

Linux help on windows 8

I need to set up 2 partitions on my Toshiba windows 8 laptop, problem is that it wont read USB boot options and I have no DVD's to load Linux mint as my 2nd OS. How do I set up mint on my laptop? — Preceding unsigned comment added by 204.42.31.250 (talk) 04:43, 8 September 2013 (UTC)

Before you start messing with partitions, there is a possibility you could irrepairably damage your Windows 8 installation so make sure you have backed up and have a means to reinstall Windows and all your programs and drivers.

You can download the Mint installation ISO image from linuxmint.com and burn it to a blank DVD disk, making sure you create the DVD correctly and NOT simply writing the ISO to the DVD as a regular file. You can also use the same ISO image to make a bootable USB drive, using a utility like UNetbootin.

To make your laptop boot from the USB drive, watch during your PC's boot up for a prompt to enter the BIOS setup screen by pressing F2 - it might only be visible for a second or two. One of the BIOS screens will let you change the boot order to include a USB device. You could also try pressing F12 during booting, and see if it offers a boot from USB option, though that might only appear if the USB drive is plugged in. However, if your PC came with Windows 8 preinstalled, it probably has UEFI installed instead of the BIOS. In which case, this article is the place to go. Note that you might have to turn off UEFI#Secure boot in order to install a linux OS - but then again Mint is based on Ubuntu which claims to support Secure boot. Astronaut (talk) 04:16, 9 September 2013 (UTC)

Khan Academy

I was tinkering around in the computer programming section in the Khan Academy and was wondering what language they use. It doesn't look like any of the languages I know. Does anyone have any idea? Is it some form of basic html coding? 202.65.133.122 (talk) 04:47, 8 September 2013 (UTC)

At https://www.khanacademy.org/cs/programming/intro-to-programming/v/programming-tour it says javascript. Rojomoke (talk) 05:14, 8 September 2013 (UTC)

Admin problem

Hi, I am the only user and administrator of my computer running Windows 7 Ultimate version for 1 and half years. I was able to format pen drives and cds and dvds. But now, when I try to format any, it shows the message Windows was unable to complete the format. I can't delete or change any files in pen drives or cds. It shows you need permission for this action. What should I do?? Benison talk with me 07:32, 8 September 2013 (UTC)

What is "streaming" in this context?

Hi. I found an interesting interview with the art director of Grand Theft Auto V, Aaron Garbut. Everything he says makes me wish I could sleep for nine more days, but one part is also confusing:

On the streaming side we’re able to do so much more. That’s let us make the world not just a lot bigger but much more detailed than IV was. There’s just so much going on, not just on the backdrop of the world but in the life on the street.

After confirming my hunch that Google is absolutely useless for the terms I'd use, I came back to Wikipedia (where I found the article in the first place), and found Stream (computing). However, I'm basically retarded on computers and the jargon is scary, so I wasn't happy to see seven choices.

Can someone point me in the right direction, given Garbut's context? I'm not sure I can learn on my own from there, but I can try. InedibleHulk (talk) 14:11, September 8, 2013 (UTC)

My understanding of "streaming" when talking about expansive open-world games is like this: in "level oriented" games (e.g. Half Life 2) all the geometry and textures associated with a level are all loaded from disk into RAM in one go; when the player moves to another level there's a sizeable pause as a whole new geometry set, and a whole new bunch of textures, are loaded in (from the relatively slow rotating media). It's a bit of a pain in games like HL2, but the designer can choose where to put the breaks, so they're in places where the action and narrative are at a low ebb - it's like a change of scene in a movie. But in an open world game like WoW, Skyrim, or GTAx, this just isn't acceptable behaviour - you want the player to be able to walk, drive, and fly at full speed, in any arbitrary direction, forever (within the confines of the massive map), and never have a pause. So rather than have the world be a single, modest size mesh, an open world game was to segmentalise the world into thousands of mesh blocks. The game keeps in RAM all the blocks the player can see (the one they're in, the ones adjacent to it, and ones further away that make up the background). If the player drives north, the game has to load new blocks corresponding to the terrain north of their current position, and (because the blocks are held in a finite RAM cache) it may have to purge blocks that are no longer relevant. In addition to terrain meshes, this has to be done with textures, actor meshes (you get different cars in different parts of town), lightmaps, sounds, and maybe scripts too (e.g. there's no little having the railroad scripts in memory when the railroad blocks, the rail car meshes, and all the associated textures and sounds, have been purged from the cache). The trick with all this is doing this without it being evident. RAM is much (much much) smaller than the size of the world and all its contents, and the world is primarily stored on slow rotating media (depending on the game and console, a magnetic hard disk or optical media). There's only so fast they can pull that data from that media, and organising things so they can always guarantee to get what they need is a difficult data-structure challenge. Occasionally they fail to keep up (as GTA3 on PC did sometimes) and you see "geometry popping" (when objects "pop" into view, having been loaded too late, or change from a chunky low-resolution mesh intended for distant viewing to a more detailed one intended for close up too late) or "texture popping" (where detailed textures, which should have been loaded to replace chunky distance ones, don't make it in time, and things briefly look oddly SNES-ish). They use multi-scale assets (geometry and texture) so you can look at a wide expanse at a great view distance so (a bit like zooming in and out of Google maps) a given block might be represented at several different scale levels by meshes and textures at different degrees of detail. TL;DR: the world doesn't fit into RAM, so they have to cleverly stream chunks of it from disk and assemble them all together on the fly; if they're good at it, the world can be as rich and detailed as they want, and the player can move around as they like without noticing all the stuff appearing and disappearing just out of sight. -- Finlay McWalterჷTalk 14:46, 8 September 2013 (UTC)

Thanks a lot, Finlay! More than I expected, and also clearer than I'd hoped. I'm even more pumped for this game, now that I know why. InedibleHulk (talk) 14:51, September 8, 2013 (UTC)

The trouble is that, once you know how they do this, you start to see the little slights-of-hand they pull to make it work, and (like The Truman Show) once you see the illusion, your suspension of disbelief is a little tarnished. You notice how the terrain in Fallout 3 is oddly undulating (to limit the draw distance), that it's always really cloudy atop Skyrim's mountains (so you don't see how chunky the land textures are), and how the urban canyons of GTA3 are hillier than you'd think (again to limit the draw distance). Games hardware, and game engines, are much better at this than they used to be, making the illusion much better (without forcing the designer to contort the world to make drawing it tractable) - Saints Row: The Third seemed to me to go out of its way to have very long straight flat city avenues, just to brag how good their engine was. -- Finlay McWalterჷTalk 15:07, 8 September 2013 (UTC)

Yeah, I'd already noticed things like this, and vaguely figured draw distance problems were somehow related to memory. Maybe now that the curtain is opened a bit wider, it'll bother me even more. From the screenshots and trailers, GTA V has solved the problem better than any PS3 game yet. Lights and textures in the distance look amazing. If it's even close to that in regular play, no complaints. InedibleHulk (talk) 15:18, September 8, 2013 (UTC)

Just remember that they won't preview the scenes that look less impressive. If Rockstar's past work is any indication, it'll look great, but like any promo, they'll be careful only to pick the best sections for demoing. Mingmingla (talk) 17:01, 8 September 2013 (UTC)

Oh, no doubt. I actually hope they left a few clipping issues. I felt a real connection with Niko Bellic when the camera zoomed in to the backs of his eyeballs. And who doesn't like falling into the odd blue Hell? But no, no cautious optimism here. Too big to fail. InedibleHulk (talk) 17:58, September 8, 2013 (UTC)

Too big to fail is right; its £170M cost is 0.1% of the entire GDP of Scotland. If that fails, we'll have to go back to scraping a living hunting for haggises. -- Finlay McWalterჷTalk 21:53, 8 September 2013 (UTC)

PDF --> Images?

Next in my series of PSP-media questions... although I've solved the problem of viewing .txt files on it (using "jpegbook" to convert a text file to several JPEG images for easy hassle-free viewing) I have but two PDF storybooks I'd like to read on there also. So pretty much I'd like a program that turns a PDF document into images... preferably one for each page. Anyone know of something like that? Thanks! --.Yellow1996.^(ЬMИED¡) 17:56, 8 September 2013 (UTC)

With Imagemagick:

 convert -density 150 in.pdf out%04d.jpg

although you'll probably get better results if your PSP viewer can read PNGs rather than JPEGs. Experiment with the -density value so you get readable text without producing giant files. -- Finlay McWalterჷTalk 18:07, 8 September 2013 (UTC)

Thanks for the quick reply, Finlay. Unfortunately I'm quite poor at using cmd tools, and got "Invalid parameter - 150" when I tried that. Probably should also mention right now that I'm on Vista HP SP2, sorry for not specifying earlier. What did I do wrong? Thanks, --.Yellow1996.^(ЬMИED¡) 18:18, 8 September 2013 (UTC)

Windows, it seems, has its own convert.exe utility, which is for something quite different. So you need to explicitly specify the convert.exe that came with the ImageMagick install. It's probably something like

          "c:\Program Files"\Imagemagick\convert -density 150 in.pdf out%04d.jpg

-- Finlay McWalterჷTalk 18:32, 8 September 2013 (UTC)

Unfortunately I'm still getting the same error, even when I open the command prompt right in where I have Imagemagick installed (it's in a folder on my desktop) and when I tried to manually type the path into the cmd window it said the path couldn't be found... also, where are all the .jpegs going to appear? I don't see a specified output path? --.Yellow1996.^(ЬMИED¡) 18:45, 8 September 2013 (UTC)

What's with the "%04d" bit? I'd try using a more normal output-file name and see if that helps. --Trovatore (talk) 19:19, 8 September 2013 (UTC)

It's the name template for the output names. Because a PDF has multiple pages, and JPEG only one, this means there will be multiple JPEGs output, and we want to make sure that the names sort okay. With this, JPEGs will be called out0001.jpg, out0002.jpg, etc. -- Finlay McWalterჷTalk 21:06, 8 September 2013 (UTC)

Oh, I see. Well, then I wonder if Yellow might be running into problems with the Windows command shell. Maybe try escaping the percent sign somehow? --Trovatore (talk) 21:09, 8 September 2013 (UTC)

I suspect it has something to do with the path... (because as I said before, I'm quite bad at using command utilities! ;)) though thankfully I've found an alternate solution (see below.) --.Yellow1996.^(ЬMИED¡) 03:05, 9 September 2013 (UTC)

If it had been the path, the problem should have been resolved when you specified the path explicitly. I'm still betting on the percent sign. My guess is that the Windows shell interpreted the percent sign as meaning something, and passed something different to convert.exe than what you actually typed.

You might try putting double quotes around "out%4d.jpg", or putting a backslash before the percent sign. --Trovatore (talk) 04:43, 9 September 2013 (UTC)

When you initially said "escape" the character, I though to do the backslash too - unfortunately it didn't work (same error) and quoting it didn't work either. Thanks for the suggestions though, Trovatore. --.Yellow1996.^(ЬMИED¡) 01:07, 10 September 2013 (UTC)

Unable to get Imagemagick to work properly, I ended up finding this site which does the conversion quite well. I'm still curious as to why it wasn't working though. Oh well - at least my problem is solved! Thanks, Finlay! :) --.Yellow1996.^(ЬMИED¡) 19:14, 8 September 2013 (UTC)

USB Ports

After unplugging this USB end from my Toshiba Satellite series laptop running windows 7 (after waiting for it to eject), both USB ports immediately quit working. They don't recognize any device, and don't even register anything is plugged in. The iPod won't even charge. I've tried all the conventional ways I can find online to remedy the situation, including updating drivers, deleting the USB ports in devmgmt and restarting, searching for upper/lower filters, downloading Microsoft fix-it, but nothing could be found. Have I somehow disengaged them from the power source, possibly? I'm really at loss as to what to do without having to take it in; it's an aging computer, and I wouldn't want to have to spend too much to do repairs. Thanks --Hubydane (talk) 22:25, 8 September 2013 (UTC)

As you've mentioned, it's an aging computer - and unfortunately that means there's a great possibility that the USB port has simply quit from age. Sounds like you've tried a lot of methods, so this is probably the case; it happens with old computers, especially if you've used the ports a lot (charging devices etc.) Incidentally, I'm typing this on a 5 year old Satellite, but my USB ports can go a while without use (sometimes weeks.) Also, I would definitely not reccomend you try and replace them yourself (unless you're a hardware expert, that is!) so if you really need them then I'd take it in to a repair shop. Good luck, --.Yellow1996.^(ЬMИED¡) 03:13, 9 September 2013 (UTC)

Yes, if both USB ports stopped working at the same time then it isn't just wear on the USB sockets themselves. I don't own a Toshiba Satellite, but if the USB ports are together then it might just be a break where the dual USB unit is soldered onto the motherboard. (Possibly an easy repair for the computer workshop.) Dbfirs 08:05, 9 September 2013 (UTC)

After a bit more investigation, I noticed the black bit in the port that fits with the plug is missing, it appears to have broken off. However, the other port is still missing. I'm not sure the likelihood of them being connected, as they are separated by an Ethernet plug and are more than an inch and a half away from each other. So, I know four sure why one plug isn't working, but after some research soldering is the only option to replace the USB plugs; at this point it's whether it'd be worth it to replace or to just give in and buy a new laptop, since its about time for an upgrade anyways.--Hubydane (talk) 12:20, 9 September 2013 (UTC)

I would guess that with that plastic bit missing, the pins are able to short against the grounded outside edge of the socket. If they are on the same power circuit, then neither one will work. I would expect the USB controller to detect the overdraw of current and shut down just one port, but it is possible that the design shuts down both. I'm surprised Windows isn't popping up a message to let you know about the problem - I know I've seen it before when a port is overloaded. If that is the problem you may be able to get by for a bit by sliding a piece of paper or thin cardboard between the pins and the side of the port, and if you're lucky the other port will start working again. I don't have a name (talk) 13:14, 9 September 2013 (UTC)

September 9

4K pass-through on A/V receivers - Is it a scam/marketing hype or a real feature?

My brother is looking for a new receiver. I went shopping with him today and noticed that a number of A/V receivers are claiming to be "4K ready". However, these receivers only seem to be offering:

1. 4K Upscaling
2. 4K Passthrough

The first is largely irrelevant as a 4K TV will upscale anyway. My question is about the second bulletpoint. If all the receiver is doing is a pass-through, how is that different from any other HDMI connection? IOW, if all the receiver is doing it passing through an HDMI connection, what difference does it make if it's HD or 4K? A Quest For Knowledge (talk) 02:22, 9 September 2013 (UTC)

Resetting my default monitor resolution in Linux Mint

I've been running Linux Mint with the Cinnamon desktop on my laptop for the last few weeks, much of the time using an external monitor. A couple of days ago I ran a game which resized my external monitor to 640x480 and now it is stuck in that resolution; the laptop screen is not affected. Mint's display tool seems to hang when I try to resize the external monitor back to something more useful. How can I get Cinnamon or X or Mint to forget it ever saw the external monitor, so next time I plug it in, it will go "Ah, a new monitor; let get the best screen resolution"? Astronaut (talk) 04:31, 9 September 2013 (UTC)

mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup and then reboot. -- Finlay McWalterჷTalk 10:34, 9 September 2013 (UTC)

Running first Java program on Eclipse

I've typed out the introductory program in Java in a Nutshell into Eclipse exactly as the program is shown but I'm getting an exception. Could someone explain what I'm doing wrong? The program is:

public class Factorial {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		int input  = Integer.parseInt(args [0]);
		double result = factorial(input);
		System.out.println(result);
		
	}

	private static double factorial(int x) {
		if (x < 0)
			return 0.0;
		double fact = 1.0;
		while (x > 1) {
			fact = fact * x;
			x = x - 1;
		}
		return fact;
	}

}

And the exception that I'm getting is: Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0 at Factorial.main(Factorial.java:8)

I've double checked my typing and it's the same as what's in the book. Line 8 is the line with Integer.parseInt in it and the parseInt is in italics but I'm not sure why. What am I missing? Is it something in the way I've set up Eclipse? Thanks, Dismas|^(talk) 10:53, 9 September 2013 (UTC)

The line int input = Integer.parseInt(args [0]); is accessing the first member of the array args, which is supplied to the program by the OS when it starts the program. That array contains, as Strings, the command-line arguments sent to the program. It looks like you're running the program without specifying any arguments, so args is == [], which means it doesn't have an element at position 0, hence the exception. A program really shouldn't throw an exception like this simply on seeing unexpected input - it could check args.length>0 (and complain if it isn't), like this:

    public static void main(String[] args) {
	if(args.length !=1){
            System.err.println("error: factorial program needs exactly one argument");
            return;
        }

        int input  = Integer.parseInt(args[0]);
        double result = factorial(input);
        System.out.println(result);
    }

or it could do better, and iterate over args and print the factorial of each argument, making main() look like this:

   public static void main(String[] args) {
        for (String arg: args){
            int input  = Integer.parseInt(arg);
            double result = factorial(input);
            System.out.println(result);
 	}
    }

As you're running in Eclipse, you'll have to find the dialog which allows you to specify the command line args that are passed when a program is run, and there you'd put the value you wanted to pass into the running program. Or you could run the program yourself from the command line, simply by saying e.g. java Factorial 13      -- Finlay McWalterჷTalk 11:04, 9 September 2013 (UTC)

On Eclipse(3.8) in my machine one can set the command line args by:

• run -> run_configurations
• go to "arguments" tab
• add (e.g.) 13 to "program arguments" box

-- Finlay McWalterჷTalk 11:13, 9 September 2013 (UTC)

Ah! That makes sense. I never gave it a way to accept an initial value. The book uses the official JDK and runs the programs via command line. Thanks much for pointing out my error. Dismas|^(talk) 13:22, 9 September 2013 (UTC)

Yahoo mail with mpop

I'm trying to get my mail from Yahoo with mpop (ver. 1.0.27) using the following command:

mpop --host=pop.mail.yahoo.com --delivery=maildir,/var/spool/mail --auth=user --user=[USERNAME]

(then it asks for my password)

and I get:

mpop: authentication failed (method USER)

mpop: POP3 server message: -ERR [AUTH] Access to this service is not permitted.

mpop: error during mail retrieval

What is wrong? It works under Windows with POPPeeper.

79.134.238.136 (talk) 14:03, 9 September 2013 (UTC)

Hmm, it works okay with mpop for me, with the options you give. The only suggestions I have is that a) you make sure POP access is enabled for the account (it's an option you set in the webmail interface) and b) the username you specify is just the username, not the full email address: e.g. joe_blogs not joe_blogs@yahoo.com      . Note that, once you have got it working, you probably want at least to add the option --tls-starttls=on       -- Finlay McWalterჷTalk 16:48, 9 September 2013 (UTC)

I should say that the problem you're having appears not to be an incorrect password (as the error that gives is mpop: authentication failed (method USER) mpop: POP3 server message: -ERR [AUTH] Incorrect username or password. (#MBR1212). And, for an experiment, I set the username to have the @yahoo.com, contrary to my B idea above, and it still works (they're smart enough to accept it with or without). -- Finlay McWalterჷTalk 16:58, 9 September 2013 (UTC)

how can facebook.com freeze my whole PC (including mouse cursor) for a few seconds when I enter it?

I'm perplexed how my first visit each day (in private mode) to www.facebook.com can freeze my whole PC, including making the mouse cursor unable to move, for a few seconds, both in Firefox and in Chrome?

1) what is it doing during this time

2) how is this technically possible?

My best guess based on Zuckerberg's hacker past is that the 'application' is somehow clocking the whole PC in a tight internal loop, to make sure that it is not running inside a VM. However, what software can specifically do this? Is it the Flash plugin? how come the plugin does not behave this way on any other site? It's doubly weird as the page that does load is super-simple and does not need to depend in any way on anything complicated or any calculation, no animation or flash movies or anything else complicated follows...

I find it so weird that a browser, which is kept up to date and used to not trusting anything coming over random internet pages (i.e. you're not supposed to just get 'hacked' by visiting a URL, both Firefox and Chrome are supposed to be able to not have to trust the data they get) can freeze the whole computer including mouse for several seconds.

It would be another matter if this were an installed application. But it's just a web URL. — Preceding unsigned comment added by 195.56.96.233 (talk) 17:47, 9 September 2013 (UTC)

What exactly is going on here? 195.56.96.233 (talk) 17:43, 9 September 2013 (UTC)

I think it's more likely that your computer is low on ram, and going to a website that requires a lot of ram temporarily chokes your computer as it pages things out to disk.

APL (talk) 17:49, 9 September 2013 (UTC)

Yeah, it's very likely you're very low on RAM when you open facebook, since it tends to load lots of images and JavaScript. 190.60.93.218 (talk) 17:52, 9 September 2013 (UTC)

Absolutely not. I have more than 1.5 GB of Free ram with almost no applications installed since hte installation of Windows, and the laptop also has an SSD. It also has not exhibited this behavior on anything else. There is no other site that would cause this behavior, except maybe if I have an inordinate number of tabs open or something, and load something with heavy Flash in it. The idea that images and JavaScript to open the Facebook front page would cause my cursor itself to be unable to move, in boht Chrome and Firefox, is ridiculous on its face. What do you propose all that Javascript is? And loading images does not exhibit this low-level Kernel usage - there is no way that simply going to a site with a lot of images would cause my cursor and entire PC to freeze for a noticeable number of seconds. As I said, there are almost no applications, an SSD, and more than a gig of free memory. If you Google my behavior there are other reports:

https://www.google.com/search?q=going+to+facebook.com+causes+pc+to+freeze+for+several+seconds

I find the same behavior as the first link: "I'm having the same issue... I have to wait about 10 seconds before it unfreezes then I can login. After that everything works fine."

There is literally one explanation that fits perfectly well: testing whether the application is in a VM by very tightly clocking something in hardware, and seeing if the resulting profile is in line with physical hardware, or with a VM. Other applications certainly do this. But my question is, by what mechanism is Facebook.com doing this? What loop can it run so tightly, for ten seconds, that regardless of whether I have switched away from that application, the entire Operating System (and believe me, Windows 7 isn't exactly built on the idea of 'cooperative multitasking) freezes, to where I could not even type in (or switch to with alt-tab) notepad.exe, nor even move my cursor (which is very low-level in Windows).

For any experts: WHAT exactly is Windows, Firefox/Chrome, Facebook, Flash etc, doing here? 195.56.96.233 (talk) 18:41, 9 September 2013 (UTC)

I still doubt that it is testing if it is in a VM. What possible motivation does Facebook have to slow some people's (but not most) computers to a crawl in order to detect that? They don't care if you're in a VM or not. I've had Flash do similar things to my computer in the past, although not with Facebook, and it is probably due to buggy implementation of Flash, not deliberate system profiling. Have you tried narrowing down what is causing it? Try disabling Flash. If you prove it is Flash you could try using a plugin to log requests, and then block individual swf files to figure out what one is causing it. I don't have a name (talk) 19:02, 9 September 2013 (UTC)

(edit conflict) Does it still hangs when you disable flash?

The best way to be sure is to profile the facebook page using the dev tools your browsers have (the alternative way is reading it's obfuscated source), doing this, you may find where most of the processing power is going to. I would do this, but the results would be meaningless because for me facebook doesn't hang when loading. 190.60.93.218 (talk) 19:03, 9 September 2013 (UTC)

Algorithm to calculate exponentials with Decimals

This wikipedia article does well by explaining some of the exponentiation algorithms there are, however I did not find out algorithms that do calculate exponentials when these have decimals or are rationals, where can I find this information? 190.60.93.218 (talk) 17:46, 9 September 2013 (UTC)

It seems like the basic method is pretty simple to generalize to any base so you can change the division by two to a division by 10 by updating it to 10 cases. I don't know if there are any references out there for doing it that way, you may have to do your own analysis to see how efficient it is. The x^2 becomes x^10, so it seems like you lose quite a bit of speed right there. I don't have a name (talk) 18:13, 9 September 2013 (UTC)

Sorry, I just realized I misinterpreted your question. By "have decimals" I read it as meaning are encoded in a decimal format, and thought you were looking for an alogrithm similar to binary exponentiation that took advantage of fast base-10 operations instead of base-2 operations. Now I realize you meant that it should work with real exponents, not just integers. I'll see if I can find anything useful. I don't have a name (talk) 18:24, 9 September 2013 (UTC)

Oh, I didn't realize it could be misinterpreted this way, I'll try to be more clearer/careful next time. 190.60.93.218 (talk) 19:25, 9 September 2013 (UTC)

Real-to-real exponentiation is defined as $x^{y}=\exp(y\log x)$, and that immediately suggests an algorithm: Compute the logarithm of x by power series (you need to do a little extra work because of the fact that the basic power series for $\log(1+x)$ is absolutely convergent only for $|x|<1$, but this can be handled), multiply by y, and then take the exponential of the product using power series.

I'm not saying this is necessarily the best algorithm (certainly it would be annoyingly involved for pencil-and-paper), but it's at least one. --Trovatore (talk) 18:30, 9 September 2013 (UTC)

It is probably not worthwhile to calculate the log using a power series - just use the log function. Bubba73 ^{You talkin' to me?} 01:25, 10 September 2013 (UTC)

Huh? If you assume you have the log function available as a black box, then why not the function $f(x,y)=x^{y}$ as well? --Trovatore (talk) 02:04, 10 September 2013 (UTC)

Most computer languages have log and exponential functions built in, but not raising a number to a real power, like the OP is asking about. Bubba73 ^{You talkin' to me?} 02:12, 10 September 2013 (UTC)

pow() is part of the C standard. (C and C++ are the only programming languages that really count.) --Trovatore (talk) 02:19, 10 September 2013 (UTC)

Then why is the OP asking? Since he is asking for an algorithm to do it, maybe he doesn't have it built in. Bubba73 ^{You talkin' to me?} 02:38, 10 September 2013 (UTC)

Very true. So why do you assume he has exp and log? --Trovatore (talk) 02:51, 10 September 2013 (UTC)

Just about everything I know of have them. And if he doesn't know about the method with exp and ln, telling him to calculate them with a power series is not a helpful answer (and that is not a good way to calculate them either). Bubba73 ^{You talkin' to me?} 02:55, 10 September 2013 (UTC)

Exponentiation#Rational_exponents and nth root algorithm should give you the information that you need. Real exponents can be approximated closely by a rational exponent. I don't have a name (talk) 18:33, 9 September 2013 (UTC)

old RAM

Hello, so I have a relatively new (if low-end) PC but it only has 4mb of RAM in it. I have been meaning to buy another 4mb of ram. And then at the weekend I found the motherboard from my 486, which is probably about 12-15 years old. It had a load of RAM in it. Can I put that RAM into my new computer, or is that a ridiculous thing to do? Thanks! Horatio Snickers (talk) 19:57, 9 September 2013 (UTC)

It's a ridiculous idea, especially because your 486 may have 4 MB of RAM, but your "relatively new" PC most likely has 4 GB. One per mil of old slow RAM won't make much of a dent (and no, it will not remotely work - the fastest 486 RAM was designed to work of a 50 MHz memory bus, and current PCs are somewhere near a GHz, and use a different bus, too). --Stephan Schulz (talk) 20:27, 9 September 2013 (UTC)

Your new computer likely has 4 gigabytes of RAM, or 4GB. The RAM modules in your old 486 machine likely won't fit the new machine (has a different pinout, clock rate and and architecture). It almost certainly won't work. Fast track obsolescence is the rule in computer hardware. --Mark viking (talk) 20:43, 9 September 2013 (UTC)

Concur with previous comments by Stephan Schulz and Mark viking. Old SIMMs are physically incompatible with current memory sockets.
Please see Single in-line memory module (SIMM), the first image on the page shows quite clearly the physical difference between early (30 pin) and later (72) pin memory modules. Secondly, if your new computer does already have 4 Gigabytes of RAM, then any extra compatible memory you install will be unusable unless you are using a 64 bit operating system. See Microsoft web page: "Memory Limits for Windows Releases". Also see Dual in-line memory module for what current memory 'sticks' look like. --220 of ^Borg 04:35, 10 September 2013 (UTC)

September 10

Looking for a software for looking up in a plain text dictionary

I have a plain text dictionary with 900,000+ vocabularies. I intend to export the vocabularies matching some RegExps, such as "^A[a-z]+e$", "^[a-z]+ion$" and so on. Thus I am looking for such a software to do this work. My OS is Windows. Please recommend some good softwares to me, thank you in advance. --Capim Dourado (talk) 13:02, 10 September 2013 (UTC)

Revisiting the Mac Question

After more research, and a decline of my fanboy attitude after using a friend's new MacBook (the one with the retina display), I've come to a realization; that is entirely too much money to buy a beefed up MacBook that is nearly impossible to service in any way, shape, or form. So, with that being said, I have a new set of questions. Keep in mind I will use this laptop for regular user activities (web browsing, word documents, etc. etc) with an added gaming scene with League of Legends, as well as music and video editing from a go pro and other various mediums.

1) I am now looking at a MacBook Pro (the newest model before the unserviceable upgrade in the retina display models), that has

       - 2.3 GHz, i7 processor
       - 4GB DDR3 RAM, 500 GB HD
       - NVIDIA GeForce GT 650M 512MB Graphics

Is this computer capable of smoothly handling what I would need it for?

2) If not, would the third party upgrades be a viable option?

2.1) if yes, what third party upgrades should be made? (I'm guessing RAM) and would anyon care to suggest which brand of third party upgrades?

I feel fairly confident in my ability to do the add-ons myself; I've spent more time with my Toshiba Satellite open than I'd like to admit. My main concern is taking the declined GHz and GB of RAM in order to save big bucks, and be able to upgrade and maintenance the machine compared to the retina display models.

Thanks, again!--Hubydane (talk) 14:35, 10 September 2013 (UTC)

I suspect that the 2.3 GHz i7 is good enough, but I'd go with the slightly higher model for the better graphics card. I also found the switch from HDD to SDD to be the single best experience booster I ever had with a laptop. Rumors are that a refresh of the whole MacBook Pro line is overdue, so you might want to wait a few days (but that is always true, and I've had good experiences with a very fresh Powerbook G4 (free upgrade between order and delivery) and a slightly riper MacBook Pro (updated 2 month after I bought it) ;-). --Stephan Schulz (talk) 15:30, 10 September 2013 (UTC)

ill definitely be waiting (at least until the end of the month) before buying, so I will keep an eye out. What graphics update should I be trying to find? My searching has been limited to Amazon...I'm cheap by nature, but I can't seem to find an upgrade without going to the retina display model, which is what I want to avoid. When mentioned upgrading, I was speaking off additional RAM, but now my interest is piqued. How feasible is switching to SSD in a MacBook? Is appealing because it would have the SSD of the newer model, but non of the soldering setbacks.--Hubydane (talk) 17:47, 10 September 2013 (UTC)

You can order the MacBook Pro (no retina) with an SSD, too - I did it nearly 4 years ago. I don't know how easy it is to switch the built-in drive with an SSD. I'm cheap, too, but time is relatively more precious than money at this stage of my life, so I never bothered. The Apple Store is down at the moment (putting in fancy new iPhones, I guess), but I distinctly remember that one of the higher frequency MacBook Pros came with a 1GB graphics card. Changing the graphics card in a notebook is not usually feasible.

Would the SSD be soldered (and thus much more difficult to deal with) like the retina models? I can't seem to find any mention. And is it really -that- much better, to upgrade to the 512 SSD on the Apple website is still $400.--Hubydane (talk) 18:37, 10 September 2013 (UTC)