Wikipedia:Reference desk/Archives/Computing/2008 February 19

= February 19 =

OpenGL over SSH
I have xvfb installed on a headless SSH server. I can run firefox and other X programs over SSH. When I run glxgears, it is slow, running at around 300 fps. But when I use -info, it says that the graphics card is a Radeon X1600. That is the graphics card that my laptop runs, the one I'm using to access the server. THe actual server has no graphics card! Why does it say that the server has an X1600? —Preceding unsigned comment added by 75.31.170.32 (talk) 03:25, 19 February 2008 (UTC)


 * When talking about the X Window System, the server is the end that provides the display, and the clients are the programs that connect to that display. See X Window System. --Bavi H (talk) 04:39, 19 February 2008 (UTC)


 * Either you're talking about a different xvfb, or it's completely unnecessary as you're not actually making use of it. --tcsetattr (talk / contribs) 05:00, 19 February 2008 (UTC)
 * What are you talking about? D\=&lt; (talk) 05:44, 19 February 2008 (UTC)


 * Xvfb (virtual frame buffer) is basically a phantom X server - it behaves like an X server so that programs can connect to it and run, but it doesn't display anything anywhere. It's used when you have some program that requires X but you can't or don't want to run an X server. If I am reading everyone's mind correctly, our friend from 75.31.170.32 is under the misconception that he needs to run an X server on his headless machine in order to be able to ssh in and run X programs. (This is a misconception caused by a failure to think through the structure of the system as Bavi H pointed out.) So he chose Xvfb, being the server that doesn't actually contain any drivers for graphics hardware. But he's not actually using it. The X clients on his headless machine are connecting (through ssh's X11 forwarding) to the X server on the other machine. Thus Xvfb is unnecessary.


 * Now that I've typed all that, upon further reflcetion, I still prefer my comment in its original not-so-long-winded form. Oh well. --tcsetattr (talk / contribs) 07:31, 19 February 2008 (UTC)
 * Ah. Is it possible to actually connect to a remote X server? D\=&lt; (talk) 11:58, 19 February 2008 (UTC)
 * Yes, that's what the clients do. But I guess what you're asking is whether you can connect to a remote virtual-frame-buffer server via some other channel (unrelated to the X protocol) and view the frame buffer remotely. Yes, if the server supports it: that's exactly how xvnc works. I don't know of any other examples. -- BenRG (talk) 17:43, 19 February 2008 (UTC)
 * Thanks everyone, but this is very confusing. Are there any good intros to the X windows system? The wikipedia article is too advanced for me.  —Preceding unsigned comment added by 75.31.170.32 (talk) 02:45, 21 February 2008 (UTC)

examining old Mac fonts
I have weird hobbies. I want to get a fatbits view of some ancient MacOS fonts (Los Angeles and Geneva 24). ResEdit would be the appropriate tool, but it doesn't run anymore. Suggestions? —Tamfang (talk) 05:52, 19 February 2008 (UTC)


 * [www.nothickmanuals.info/doku.php/minivmac Mac on a Stick]? --grawity talk / PGP 09:26, 19 February 2008 (UTC)
 * I could send you a HD image, if you don't want to google for System * images.


 * Turn on the screen magnification in the "Universal Access" control panel ("System Preferences"). But if you want the true "fatbits" experience, be sure to select "Options..." and turn off "Smoothing".
 * Atlant (talk) 12:58, 19 February 2008 (UTC), revised 23:13, 19 February 2008 (UTC)


 * Magnification is no help if I can't open the suitcase. —Tamfang (talk) 06:58, 20 February 2008 (UTC)

Concatenation in Perl
In Perl, this works as intended: But this will only print the number: Why is that? Is there a way around it? I've been pondering this for quite some time. Thanks! ›mys id (☎∆) 08:54, 19 February 2008 (UTC)
 * The first isn't a string, why would you expect to be able to concatenate? Perl defies strong/weak typing definitions. D\=&lt; (talk) 10:29, 19 February 2008 (UTC)


 * Shame on you for not enabling warnings! (Seriously, the perl world has been begging people to enable warnings for the last 1000 years yet still there are people asking ridiculous questions that the warning would have answered! How long is it gonna take? Will there have to be a perl version that electrocutes the user when warnings are not enabled?)
 * You are printing $a/40300 and then concatenating the string " meters\n" onto whatever print returned, and throwing away the result of the concatenation. You should put the function-call parentheses around what you intend to pass to the function, as in

print(($a / 40300) . " meters\n");
 * Other similar things are

print +($a / 40300). " meters\n";
 * in which the unary + forces a different syntactical interpretation, and

print $a / 40300, " meters\n";
 * in which there are 2 arguments being passed to print. But the first way is the easy way: if you never omit the function-call parentheses, you'll never be surprised at where the parser decided your argument list ended. --tcsetattr (talk / contribs) 10:35, 19 February 2008 (UTC)
 * Thanks, that completely clarifies it. Yeah, shame on me. But I'd actually prefer Perl enabling the warnings by default rather than electrocuting me. ›mys id (☎∆) 20:08, 19 February 2008 (UTC)
 * Oh, wow that's stupid. Why do scripting languages insist on having syntax-defying keyword versions of the print statement that muddle everyhing up? Just force the user to use parentheses.. .D\=&lt; (talk) 11:55, 19 February 2008 (UTC)
 * It has nothing to do with the print statement. Any function would behave the same way.  It has to do with Perl's optional-parens-on-function-calls feature, which is very handy and certainly worth having this little wart on it, since it will warn you about it if you do it wrong.  --Sean 15:06, 19 February 2008 (UTC)


 * It is a pretty horrible feature. Consider the examples given in perlfunc:

print(1+2) + 4;    # Prints 3. print (1+2)+4;     # Also prints 3!
 * What the author is telling us with his excited commentary is that he thinks the two lines might reasonably be expected to have different results. But surely no reasonable language would give syntactical significance to horizontal whitespace! --tcsetattr (talk / contribs) 21:59, 19 February 2008 (UTC)

Start-up problem in Windows XP, German message
When I start-up Windows the following message keeps popping up:

--- '''Setup '''UPDATE [-u] [-f] [-n] [-o] [-z] [-q] [-l] '''-u Unbeaufsichtigter Modus '''-f Erzwingt das Schließen anderer Programme beim Herunterfahren. '''-n Keine Dateisicherung für Deinstallation. '''-o Überschreibt OEM-Dateien ohne Abfrage. '''-z Kein Neustart nach Abschluss der Installation. '''-q Hintergrundmodus (keine Bildschirmausgabe). '''-l Listet installierte Hotfixes auf. '''OK  ---

Although I can just click OK and go on, it is annoying to always have to do it.

I think this message is the result of a open-source program installation that went wrong. I don't remember exactly what program it was. But I was to get rid of it.

Any ideas? Mr.K. (talk) 09:10, 19 February 2008 (UTC)
 * If you can remember when about you tried to install this software, search for new files by date in that timeframe.--Ouro (blah blah) 14:39, 19 February 2008 (UTC)


 * Googling those messages points to some kind of Microsoft service pack stuff.  --Sean 15:10, 19 February 2008 (UTC)
 * Looks like xp sp1 to me. Open source now, was it? --Ouro (blah blah) 17:18, 19 February 2008 (UTC)


 * Ok, perhaps it was not open-source. But the message is still there. And going to this German page doesn't help me actually. I don't even think it matches too much. There are general term in the message. Mr.K. (talk) 23:11, 19 February 2008 (UTC)
 * Search your disk the way I suggested and tell us what you found. --Ouro (blah blah) 12:44, 20 February 2008 (UTC)

Defragment fails.
I decided to defrag today. At first it went well, but at about 15%, it suddenly stops and gave this message

"Defragmentation is complete for: (C:) Some files on this volume could not be defragmented. Please check the defragmentation report for the list of these files."

I tried running it again but it just gives the same message after about 2 minutes in. I don't understand what's going on, but it looks pretty messed up (down there). I should point out that the last time I defragged this disk was probably over 2 years ago... So I want to tidy it up now, but now I can't? Help.

View Report:

I did have a look at Defragmentation, but couldn't find any info that might help. Aurora sword (talk) 10:25, 19 February 2008 (UTC)
 * File system damage probably. Boot from your XP install disk, hit R to enter the recovery partition and run

chkdsk /R
 * D\=&lt; (talk) 11:52, 19 February 2008 (UTC)

Just a small reminder, please back up everything that you need. Use another administrator account to do the backup for Milka's documents and setttings. The good news is that most of the fragmentation seems to be in the folder "documents and settings". Maybe you could back up everything, delete the user, and restore the backup?

I would suggest moving the documents and settings to another partition but it is too much hassle. I tried it and it did not work perfectly for me. Kushal 12:47, 19 February 2008 (UTC)
 * Hmm, eh. So basically what I need to do is copy those files into another disk, delete, then paste them back, correct? Might have to borrow someone's portable HD for this.. If I create the backup in the same disk that needs defragging, would it be fine or be useless? Aurora sword (talk) 17:01, 19 February 2008 (UTC)

I'd actually do it the other way around: take out your hard disk and connect it as a second drive on someone else's PC and run a diagnostic on it (Norton Disk Doctor, then Norton Speeddisk). --Ouro (blah blah) 17:22, 19 February 2008 (UTC)

It does help if it is in the same disk but NOT in the same partition. However, just to be safe, I would back it up to an external drive. On the other hand, Ouro's suggestion seems to be very good and avoids the hassle too! Do you have another computer that has the disk software that Ouro mentioned? Kushal 17:48, 19 February 2008 (UTC)
 * ...or similar open-source software that does the same but is faster and better than Windows-native Scandisk or Defrag? --Ouro (blah blah) 12:38, 20 February 2008 (UTC)

IBM RSC (RISC Single Chip)
Does anyone know where I can find detailed information about this microprocessor? I've tried the IBM Journal of Research and Development, but there isn't anything there. Google searches don't seem to turn up anything either, except for a IEEE paper that is unfortunately available through subscription only. Thanks. Rilak (talk) 11:56, 19 February 2008 (UTC)
 * Pages 200-204 *shrug* We do have a tiny article. D\=&lt; (talk) 12:00, 19 February 2008 (UTC)

Audio communications.
I have a little problem here that I doubt can be solved, but if it can, I'm sure this is the place that can do it. I would like to be able to talk to someone that lives a long way from me. Actually talk so they can hear me, via the internet. However I don't have a microphone that I can plug into my computer, and at the moment it seems unlikely that I will be able to get one. so I thought maybe you could suggest another way in which we could talk. HS7 (talk) 13:07, 19 February 2008 (UTC)


 * I see three possibilities:
 * Use headphones instead of a microphone (yes, it works).
 * Use your keyboard and text-to-speech software.
 * Send me 100$ and I will send you my book on long distance telepathy.
 * Morana (talk) 14:07, 19 February 2008 (UTC)

1 How can I talk to someone through headphones? I really can't see how that would help, unless there's something I'm not getting here.

2 The point is so that we can hear each other talking, not just hear the computer saying what we've typed.

3 I already considered that, and I'm sure if it works, I'll be just as able to do it myself.

Sorry, but thanks for your help anyway. HS7 (talk) 14:44, 19 February 2008 (UTC)
 * 1. Alexander Graham Bell's telephone was probably something similar: a speaker works the same way as a microphone. (But you probably need to hook up amplifiers, though.) And I'm not sure if the plugs are wired so that that's possible... Anyway, if you do have a working microphone, then there's Skype and Google Talk and lots of other ways to voice chat. --Kjoonlee 14:55, 19 February 2008 (UTC)

The telepathy sounds easier. I'll give that a try. HS7 (talk) 14:58, 19 February 2008 (UTC)

OK, I'll try a different approach. is there any way that with no experience with computering or engineering or anything like that I can make my own microphone from stuff around that house that noone else wants? HS7 (talk) 16:13, 19 February 2008 (UTC)
 * Assuming you have stuff that no-one wants worth at least $15 (US) or so, amazon.com is the obvious option. Algebraist 16:32, 19 February 2008 (UTC)


 * Just do what I did and steal a microphone from your local college. I admit it! The truth really does set you free, who figured? 206.252.74.48 (talk) 16:56, 19 February 2008 (UTC)

Right. I'm not going to steal anything, I wouldn't even know how. but I notice skype was mentioned up there a bit, and even I know what that is. Would it actually be possible though without the microphone? that's basically the whole problem here. HS7 (talk) 17:19, 19 February 2008 (UTC)
 * As mentioned above, no, voice chat cannot be done without a microphone. --Kjoonlee 17:31, 19 February 2008 (UTC)


 * If your difficulty in getting a microphone is cost-related, consider that microphones can be very inexpensive these days. Better yet, ask your local friends; many new PCs come with a cheapo external microphone, and a lot of people probably have at least one extra lying around they'd be willing to part with. jeﬀjon (talk) 18:40, 19 February 2008 (UTC)


 * (I'm going to assume that you're not on a laptop or something with a built-in microphone.)
 * You might try hooking up a cheap pair of headphones (cheaper the better, probably) into your computer's microphone jack and turning the mic gain all the way up. See if you can get that to work.  Some headphones will actually work as microphones that way.
 * The other option for "stuff around the house" is that if you wired a microphone salvaged from an old telephone into an audio cable salvaged from an old pair of headphones you could probably make a crude microphone that way.
 * But I agree with the folk above that the best solution is probably picking up a cheap microphone for about $5-$10, somewhere. I've seen them in drug stores for about that price.APL (talk) 19:11, 19 February 2008 (UTC)

I've figured out another way, i could get one of those phones that you can get the internet on, that soundly like it could work. but even if it would, i think I'll just give up and buy a microphone when I can find one. I live in a little village so I doubt there will be any places that sell them near here. Thanks for all your help. :)HS7 (talk) 19:30, 19 February 2008 (UTC)
 * If you search around, you may be able to find really good prices online. I've never heard of this retailer, but this looks pretty cheap :  —Preceding unsigned comment added by APL (talk • contribs) 19:37, 19 February 2008 (UTC)

• Download skype ( for free ) and spend about £20 on a sykpe phone http://www.travelizmo.com/archives/ipevo-skype-phones.JPG this is a usb phone which enables you to chat online with any other skype user via the internet. Radiofred (talk) 23:53, 19 February 2008 (UTC)

Email Repeat Send Online Service
I subscribe to a service that requires my consent via email each and every day that I require that service. I can email them on work days in the morning but not at weekends or when I am on holiday so I lose the service for that day. Is there a service available online where I can set up one email to be sent per day to one receiving email address on a repeated basis. The email text will always be the same. Mccartrey (talk) 13:26, 19 February 2008 (UTC)
 * Maybe this site can be of help. 212.123.186.64 (talk) 13:57, 19 February 2008 (UTC)

That works a treat thanks. Mccartrey (talk) 15:00, 20 February 2008 (UTC)

iPlayer WMV
I hear from lots of websites that if one installs the iPlayer software, one can download a DRM-protected WMV of the program, and then play it in WMP. Is there a way to download these wmvs without installing extra software? Is there a site like KeepVid that works out the link format to the direct WMV? Thanks Porcupine (prickle me! · contribs · status) 14:44, 19 February 2008 (UTC)

Windows XP Pro Booting problem
I'm using Windows XP Pro in my system.the problem i have is that we i turn on my computer,windows boots up and i even see the loading screen;but once it gets to the login screen,i can only see a mouse cursor in my screen and the rest is black.I don't have any clue as to what is the problem.Please helpChidam17 (talk) 17:03, 19 February 2008 (UTC)

I believe it is some fault with the Windows XP explorer. Have you tried Ctrl + Alt + Del Control-Alt-Delete? Does the computer respond to that? If you can get to Task manager, you can go to File > New Task (Run) >> and then type in something stupid like "my computer". Explorer should start up. (This does not work if you are not logged in.)

If that did not work, you might want to reinstall Windows altogether. If you have a bootable installation CD, you might want to reinstall Windows. To back up your stuff, you can boot with a LiveCD of Ubuntu and copy your files or you can simply take the hard disk to another computer and make a backup copy of it there. Hope that helps, Kushal 17:37, 19 February 2008 (UTC)
 * Actually,

explorer
 * should work, but not "my computer". --Kjoonlee 17:59, 19 February 2008 (UTC)


 * I have this happen to me all the time, but only after I log in. First I kill the "explorer.exe" process, then I start it again using run. However, it seems that you cannot even log in. This has happened to me too, and I suggest a system restore instead of a reinstall. 206.252.74.48 (talk) 19:32, 19 February 2008 (UTC)


 * winlogon.exe should do the trick, I believe. Admiral Norton (talk) 21:13, 19 February 2008 (UTC)

Well, I had that problem with my computer before. When I entered a valid command, just that window came up but not the taskbar. Then I tried something stupid, and taskbar and desktop and everything came up along with an error message. But the bottomline is that it worked. Kushal 19:53, 19 February 2008 (UTC)

Only thing different is that for me, it happened after I logged in (AFAIR). Kushal 19:54, 19 February 2008 (UTC)

Deleting Files from Recycle Bin via Command Prompt
Hi, I was wondering if there was a way to delete individual files from the Recycle Bin, but not every file from it using cmd.exe. Also, is there some command that allows batch files to delete other programs without moving it to the Recycle Bin, or moving it to the Bin, then deleting it? Any help would be greatly appreciated. 63.28.135.182 (talk) 18:13, 19 February 2008 (UTC)


 * To answer your second question, the del command deletes files without moving them to the Recycle Bin. --Bavi H (talk) 04:00, 20 February 2008 (UTC)

computer problem
1.  My pentium PC can no longer start up from my hard disk. i can not start up from the floppy drive either. I have replaced the floppy drive with a new one so i know that its not the drive which is at fault. What do i do to get my PC hard drive working again.

2.i am running windows 95 on my PC and when i boot-up, it displays a black screen and the following message appears "a device file that is specified in the system.ini file is damaged. It may be needed to run windows. You may need to run the windows setup program again. If the file was included on another software package, you may need to reinstall the software that uses the findilc:\windows\system\VMM32\NTKERN.vxd" —Preceding unsigned comment added by Leoaboki (talk • contribs) 18:27, 19 February 2008 (UTC)


 * Did you recently install USB support? According to this forum discussion it might be the reason. Anyway, run the Windows setup (your Windows CD). Admiral Norton (talk) 21:07, 19 February 2008 (UTC)

What's wrong with this excel function?
=IF(B5<3000,*.1,IF(C5=S,x=.18,x=.15)IF(B5>3000,*.x) Bellum et Pax (talk) 21:15, 19 February 2008 (UTC)
 * Well, you have "F" instead of "IF" at the beginning. Is that it? Useight (talk) 21:19, 19 February 2008 (UTC)
 * Err yeah, it should be =IF in the beginning, but there's something else too. Bellum et Pax (talk) 21:21, 19 February 2008 (UTC)


 * There is something missing after "... x=.15)".  Since IF only takes three parameters, it should probably be a closing paren, but then I don't know where that leftover IF goes.  --LarryMac  | Talk  21:47, 19 February 2008 (UTC)
 * Aside from that, I don't know what *.1 and *.x do. Is this a function within a macro?  --LarryMac  | Talk  21:56, 19 February 2008 (UTC)


 * For one thing you know something's wrong when you have 3 open parens and only 2 closed parens. Check how you've got your IF functions nested, there is definitely an error there. And I'm dubious that your use of the asterisks in this way is kosher—"*.1" is not a valid value for a cell to hold (perhaps you mean B5*.1?) --98.217.18.109 (talk) 23:25, 19 February 2008 (UTC)


 * I think a better question to work out what's wrong is "What is it supposed to do?" Confusing Manifestation (Say hi!) 00:09, 20 February 2008 (UTC)
 * The intention is to take a cell (B5) and multiply it by .1 if it's below 3000, or multiply it by X if it's above 3000. X is defined by weather another cell (C5) is either an S or an M. If it's S then multiply it by .15, else multiply it by .18. —Preceding unsigned comment added by Bellum et Pax (talk • contribs) 05:36, 20 February 2008 (UTC)

=IF(B5<3000,B5*0.1,IF(C5="S",B5*0.15,B5*0.18)) –Outriggr § 06:00, 20 February 2008 (UTC)
 * The problems are:
 * You can't write *.1 in vacuum. It needs to multiply something (e.g. B5*.1).
 * You can't define a variable inside a formula this way (I don't think so, anyway).
 * Even if x was defined, it needs to be B5*x (multiplying B5 by x) and not the meaningless *.x (with a missing multiplicand and a superfluous period).
 * You can't write two functions one after the other (the IFIF thing)
 * The S is a string and thus should be in quotation marks, "S".
 * The first IF has no closing parenthesis.
 * The third IF need 3 parameters.
 * You have conditioned on B5>3000 in a branch where already B5>=3000. You need to decide what you want in the case B5=3000.
 * No offense is intended, but a better question would be what is right about this formula. You should familiarize yourself with simpler expressions first before writing more complicated ones.
 * For a correct expression, you can use Outriggr's version, or the slightly shorter:

=B5*IF(B5<3000,0.1,IF(C5="S",0.15,0.18))
 * -- Meni Rosenfeld (talk) 11:00, 20 February 2008 (UTC)
 * I figured the person should infer all that, given a correct expression. :) Good job "factoring out" that B5! –Outriggr § 00:26, 21 February 2008 (UTC)

Piracy
hi i'm making a program about piracy. i'm looking for some experts who know a lot about piracy. can anybody help provide me with some infomation about piracy. not just computer piracy, but all piracy (eg books, music, video game). if anybody can help provide some infomation or point me in the direction of some one who can i would appreciate it. thanks for you time POKEMON RULES (talk) 21:28, 19 February 2008 (UTC)


 * http://www.gnu.org/philosophy/words-to-avoid.html#Piracy --tcsetattr (talk / contribs) 21:31, 19 February 2008 (UTC)


 * A great book to read (and it's available free online) is Lawrence Lessig's Free Culture, which discusses the history of "piracy" and intellectual property protection in its early chapters and discusses modern issues as well. It's a great over-all source and is very readable. Online at http://free-culture.cc/. --98.217.18.109 (talk) 22:30, 19 February 2008 (UTC)
 * I would try emailing small movie and game studios, and indie artists, and maybe an author or two (Terry Pratchett for instance is ususally quite good at answering letters even if it does take a while) although book piracy is a very rare occurence, and asking them some things. Many small studios and artists will be quite happy to talk to you, and won't always give the standard large studio "piracy = lost sales = bad" thing. Asking on wikipedia will possibly leave you with a biased article as Open Source Software people and Creative Commons people have a tendancy to be anti copyright, as the above people have shown (no offence to those people, but I believe people should have the right to protect their work if they so wish, and see piracy as generally quite a bad thing for a studio but it does have its upsides, for instance free advertising, plus if you just want to get your message seen by a lot of people) TheGreatZorko (talk) 09:09, 21 February 2008 (UTC)


 * You asked for experts - I guess you could say that Peter Blake is terminally knowledgeable in the subject. Commercial mariners in many parts of the world need to know about piracy too - the Malacca Straits are most famous for it. Leisure sailors planning a round-the-world voyage often have concerns in this area too - "to take a gun or not?" used to be a recurring question when I used to read sailing newsgroups.
 * As for copyright infringement, I'm afraid I can't help you. 81.187.153.190 (talk) 23:31, 24 February 2008 (UTC)

Running wiki offline
Hi all, I have a question about wether it is possible to run MediaWiki or another Wiki offline or not. I don't have a server, nor do I have my own webspace. I know that you can run html pages offline as well, so I was wondering if this is possible to do with Wiki software as well and if so, how to get started. Thanks a lot, Amanda T / C 23:48, 19 February 2008 (UTC)


 * There are a couple ways to do this. One is to run a server locally, and install it on that. This can be very hard to do, though.
 * The easier solution is to use one of the many pre-packaged off-line wiki software packages out there (a number are listed in the article personal wiki), but depending on what you want to do with the Wiki, the best software for the job will vary. This isn't the same thing, mind you, as having Wikipedia itself available off-line, but it doesn't sound like that's what you're asking for. --98.217.18.109 (talk) 01:59, 20 February 2008 (UTC)
 * I can personally warmly recommend TiddlyWiki. Just download one html-file, no installation or anything, and you have a pretty neat little personal wiki. It's quite astonishing how cool it is. 83.250.192.60 (talk) 03:01, 20 February 2008 (UTC)
 * Thanks, that was what I was looking for, but I still prefer MediaWiki to be running like this tiddlywiki because I'm used to that now :) Amanda T /<font color="Orange"> C 05:36, 20 February 2008 (UTC)
 * If the problem is having no web hosting (as opposed to having no internet connection), then I recommend WOS. It allows you to install a MediaWiki server on your computer as easily as you can download a file and run it. You can then run it locally. -- Meni Rosenfeld (talk) 11:08, 20 February 2008 (UTC)