Wikipedia:Reference desk/Archives/Computing/2007 October 22

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[edit] October 22

[edit] What does ftp://ftp mean?

I've found it very difficult to google this expression (for obvious reasons maybe) Do anyone know the background for its use? And the "exact" meaning? 80.203.100.53

FTP is File Transfer Protocol; if you're looking for "ftp://ftp" exactly I can't help you as I've never heard of that phrase. Kuronue | Talk 19:47, 28 October 2007 (UTC)
ftp://ftp is often found at the beginning of a Uniform Resource Identifier (URI) that uses FTP protocol rather than the more common HTTP. The first 'ftp' is the name of the URI scheme (like http at the beginning of http://www.foobar.org/). The second 'ftp' because often a special machine is used to store files accessed by FTP and it is common for the hostname of this to begin 'ftp'. For example www.foobar.org may be the web server for the foobar corporation but ftp.foobar.org the hostname attached to the machine serving FTP files. A URI for the FTP server then would be something like ftp://ftp.foobar.org/some/file.name. -- Alan Dix 20:32, 28 October 2007 (UTC)

[edit] iDVD question: menu music

I am making a DVD menu in iDVD 6, and I have a little music clip to play while the menu is displayed. What I'd like to do is to have it play just once and NOT loop (I find looping DVD music pretty irritating and useless). I can't find an option that lets me not loop it; is this something about the DVD menu format in general or a limitation of iDVD in particular or can it be done in one way or another? --24.147.86.187 00:23, 22 October 2007 (UTC)

OK—poking around in the help file, the answer is apparently "iDVD just doesn't do this." Very sad, but I'll work around the limitation... --24.147.86.187 01:44, 22 October 2007 (UTC)

Edit the sound file to have a huge space at the end? If the sound at the end is uniform, an mp3 should compress it to about no space at all. —Preceding unsigned comment added by 71.195.124.101 (talk) 23:18, 24 October 2007 (UTC)

[edit] visual basic for applications

Is it possible to read the level of a sound card input at a point in time with visual basic for applications? If so how?

76.209.61.169 02:19, 22 October 2007 (UTC)

[edit] Web/Tree building programs

Does anyone know of a free program which can be used to build complex webs or trees, perhaps like a very interconnected family tree? A software specific for family trees would not work for this - it's too complex for that. I heard about something once, but I don't remember the name - only that it might have been by one of the US phone companies and that it had it's own odd coding system.

Can anyone help? Thanks. 04:00, 22 October 2007 (UTC)

There is a Bell Labs program from the early 90s you might be thinking of. See
Koutsofios, Eleftherios and Stephen C. North. "Drawing graphs with dot". 
For more recent programs of this kind, Google for 'Bell Labs graph drawing'. EdJohnston 04:21, 22 October 2007 (UTC)
Ooh! Thank you both! That's great. 04:28, 22 October 2007 (UTC) —Preceding unsigned comment added by 138.192.140.113 (talk)


[edit] Page Fault in nonpaged area- stop 0x50

    I built a computer from spare parts, being:
 
KT4V motherboard, AMI 3.1 bios

geforce 6200 256 mb DDR2 onboard memory

1.5 gb DDR 3200 mem, 1 gb, 512 mb

seagate baracuda 40gb

athlon xp 2700+

600W PSU

DVD-ROM, Floppy

System runs cool ~109 degrees F CPU, 80F case

I have tested EVERYTHING twice, except the hard drive (doesnt need drivers, btw, I checked that). Half way through XP installation I get the aforementioned stop code.

Linux works fine, though

I have a suspicion that it's the hard drive, even though that doesnt make sense for the error, but only because I am running Linux (ubuntu) off live cd and it, not using the hard drive, works fine

switching video cards out for a very old one (TNT 32mb) doesnt help either, and to reiterate I checked everything (memory using memtestx86)

I plan on putting Ubuntu on hdd to make sure hdd works tomorrow

Thank you in advance72.161.209.51 05:03, 22 October 2007 (UTC)


sorry, I forgot to add please help, excuse me, I'm American72.161.209.51 05:09, 22 October 2007 (UTC)

I very seriously doubt the hard drive is at fault. Have you tried installing the latest drivers for your peripherals? And what exactly does the STOP message mention? Splintercellguy 05:12, 22 October 2007 (UTC)

YEah, I know it doesnt make sense, although I whittled it down to that (I think). The stop message means the computer was looking for something in memory that wasn't there, which is odd I am getting this message because the memory tests good (disabling L2 cache doesn't make a difference, btw, so I think its good). I am trying to install with nothing I dont need, only card the video, nothing else.72.161.209.51 06:27, 22 October 2007 (UTC)


sorry about the double post, also72.161.209.51 06:28, 22 October 2007 (UTC)

I don't "get" this error message. Can some guy correct me... but how exactly do you get a page fault in "a non-paged area"? Or does "paged" mean a page is swapped out to the disk? Does that mean Windows isn't unswapping a page from the disk? --wj32 talk | contribs 10:27, 22 October 2007 (UTC)
I don't know, but I imagine it means that a driver followed a wild pointer to unmapped memory, which trapped to the page fault handler, which discovered there was no page to fault in and panicked. Unfortunately, like an access violation in user mode, this could be caused by almost anything. You need to look at the rest of the bluescreen information to narrow it down to a specific driver, which you might then be able to disable. -- BenRG 12:28, 22 October 2007 (UTC)
XP can be VERY fussy about hardware which other O/S's might cope with. I had a similiar problem and the culprit was the 'wrong' type of memory for the motherboard (for some reason the motherboard would only cope with 400MhZ DDR RAM, anything else, including older and slower RAM of the same type threw it. The comp worked OK until I tried to install XP. I reckon this is something to do with memory, check the motherboard manual or website to see if the RAM you are using is compatible, if not, get the right type. GaryReggae 14:06, 22 October 2007 (UTC)


Yeah, not a hdd problem, Linux loaded fine. My motherboard is supposed to be able to take the memory I have fine,72.161.209.51 21:44, 22 October 2007 (UTC) though


PROBLEM FOUND- there must be a glitch where if the hard drive is not formated previously xp install wont either. XP installed fine after I put Linux on hdd to test it. Thanks for your input! Have a nice day72.161.209.51 22:33, 22 October 2007 (UTC)

[edit] Sub-dividing PDFs

I have a number of very large PDFs which were created by batch scanning a pile of documents (not by me). Hidden inside these batches are a few documents I am interested in. They cannot be reliable mechanically distinguished from the surrounding documents. What's the best method to find and isolate these documents from the rest? Ideally I would use a system that would let me quickly flip through the documents and tag the ones I want for removal and then later have the tagged ones extracted to separate files. But I don't know if any such program and PDFs are so unwieldly. Any thoughts? --140.247.41.66 14:07, 22 October 2007 (UTC)

You don't say, but if you're on Linux or similar you can use libpoppler utilities to do things like "pdfimages input.pdf Images" to extract all the pages into individual image files for easy browsing, and then "pdftops -f FIRST-PAGE -l LAST-PAGE input.pdf output.ps; ps2pdf output.ps output.pdf" to select pages from the original document. --Sean 14:59, 22 October 2007 (UTC)
You didn't say what tools you have at your disposal. If you have Adobe Acrobat (the full version, not just the reader), you can do it using the Document->Extract Pages... dialog. If you don't, but you have a PDF reader and a PostScript printer driver, you can "print" a desired portion of the file to a PostScript file, and use a utility called ps2pdf to convert it to PDF. This is similar to the solution suggested by Sean. Another tool that can do the job is pdftk[1]. --64.236.170.228 18:41, 22 October 2007 (UTC)
Neither of those are efficient means—they require laboriously going through the PDF (as with Acrobat) or knowing ahead of time the page numbers to specifically extract. I don't think there's a program that can aid in such subdivision on the market. --24.147.86.187 23:06, 22 October 2007 (UTC)
Saying that there's nothing on the market that can "aid" is overly pessimistic. If the OP knows something about the content of the documents he want extracted, he can OCR and index the document and try to locate the portions that he want by searching. Once an approximate location is found, determining the exact starting and ending pages won't be that difficult. The problem with this approach is that when the number of pages is large, say 100000, you probably need to use a vendor that provides this kind of service, which can be quite expensive. --64.236.170.244 01:53, 23 October 2007 (UTC)
If you use the libpoppler method described in the first reply, you can browse through the different files with an image viewer (like irfanview). You might have to batch convert the files first, but I know that irfanview can at least read ps files. Then you can define a macro or a shortcut (there should be an image viewer with this functionality) to copy the currentfile to some directory. This way, you can flip through the files quickly, and copy a single file out of the collection with a single key combination. risk 12:53, 23 October 2007 (UTC)

[edit] Cangjie character generator

I'm curious about how Chinese character generators (such as the Cangjie) work, but I can't find any information on the algorithm besides a wad of uncommented (even if it were commented, I don't understand Chinese) assembly. (I'm not all that interested in Cangjie as an input method - that's pretty simple - but I'm really interested in the character generator). Any ideas? AFAIK, there isn't even a patent to examine. --196.210.103.191 15:23, 22 October 2007 (UTC)

There isn't a character generator, assuming I'm understanding what you're asking correctly. All the characters in a Han character set are designed independently. I had started a research project on this before the first time that I dropped out of college in the late 80s and the problem was that while you can (theoretically) compose Han from radicals, the individual radicals change their shapes a fair amount from one character to the next. Add in the additional complexity of mainland-Chinese Han simplification, assorted strokes which don't really belong to any radical and the task is a bit more complicated than it seems. Then there's the additional problem that you end up with a programatic system which is rather alien to what designers would like to work with and it seemed a dead end. I did have some hope that it could be accomplished for Hangul at least since the interactions of the phonetic components is a fair amount simpler, but I've never really had the time to go back to the project in the couple decades which intervened. Donald Hosek 18:10, 22 October 2007 (UTC)
From our article on the Cangjie method

In the beginning, the Cangjie input method was not a way to produce a character in any character set. It was, instead, an integrated system consisting of the Cangjie input rules and a Cangjie controller board. The controller board contains character generator firmware, which dynamically generates Chinese characters from Cangjie codes when characters are output, using the hi-res graphics mode of an Apple II computer... A particular interesting "feature" of this early system is that if you send random lowercase words to the character generator, it will attempt to construct Chinese characters according to the Cangjie decomposition rules, sometimes causing strange, unknown characters to appear. This unusual feature, "automatic generation of characters", is actually described in the manual and is responsible for producing more than 10,000 of the about 15,000 characters that the system can handle. The name Cangjie, evocative of creation of new characters, was actually very apt for this early version of Cangjie.

I do think it would be a difficult problem, but these quotes gave me some hope. I'm more confident it can be done with Hangul. BTW, In what was is it "alien to what designers would like to work with"? --196.210.103.191 20:47, 22 October 2007 (UTC)

[edit] Backing up open files

I would like my backup program to automatically backup files once per week. The problem with that is, that files will invariably be open when backup time comes. With notepad files, this never posses a problem but with openoffice files, for some reason, the file cannot be copied (restricting editing, I can understand, but innocuous copying??) while it is open. This makes me wonder, what about industrial applications - how do they backup files that are in use? I don't want to have to close my programs before backup begins (otherwise, it's not "automatic"). I like to leave any work that I'm working on open, until I finish working on it. —Preceding unsigned comment added by Seans Potato Business (talk • contribs) 16:21, 22 October 2007 (UTC)

On the PC (running Windows XP) I use a program called Drive Snapshot which does a backup of your entire drive, including any open files. It's often used with a separate hard disk, hooked up via FireWire (for example) because of the size. For details see drivesnapshot.de. I think it cost about $50; it works well and is fast. On the Mac there are a variety of cloning backup programs that work well, some of which may even be free. I use one called Super Duper. It also handles open files without complaint. EdJohnston 02:33, 23 October 2007 (UTC)
For Windows, see Volume Shadow Copy.

[edit] Blu-ray/HD DVD aspect ratios

Just wondering, do Blu-ray and HD DVD support aspect ratios other than 4:3 and 16:9 as was the case with DVD (i.e. on DVD a 2.35:1 is encoded as 16:9, with the remaining letterboxing hardcoded into the image). Thanks - EstoyAquí(t • c • e) 18:09, 22 October 2007 (UTC)

Letterboxes are rarely if ever hard coded into DVDs today. They use anamorphic format to retain maximum vertical resolution. --24.249.108.133 20:09, 22 October 2007 (UTC)

Like I said, they do it on ones with non 4:3/16:9 (they're the only two which can be signaled on DVD). I know this for a fact (also see Anamorphic widescreen, for further evidence). It's whether they're forced to do it on Blu-ray/HD DVD that I'm interested in. - EstoyAquí(t • c • e) 18:07, 23 October 2007 (UTC)

[edit] amr files

I need to edit an .amr file, is any free software out there that can do the job? —Preceding unsigned comment added by 88.106.225.214 (talk) 18:51, 22 October 2007 (UTC)

According to [2] this type of file is a cellphone multimedia file, so you'll probably need some kind of audio/video editing software. Exxolon 19:22, 22 October 2007 (UTC)

Not to worry - sorted it out! —Preceding unsigned comment added by 88.106.225.214 (talk) 19:33, 22 October 2007 (UTC)

[edit] Logout/Stop Script

I'm here to ask a question (yet again...) about an enforcitive measure to help stop him from making userspace edits. I think I would be able to do it, but I don't want to be accountable if I mess something up and screw up his account. I'm fairly certain it would have this in it, but the other parts I can think of are sketchy, though I'll try with the help of "An Intermediate Guide to JavaScript & AJAX".

if ( > ) {
      alert ("You may not edit this articlespace"). Bye!");
      window.location.href = ("http://"+document.location.host+"/w/index.php?title=Special:Userlogout&returnto=Main_Page");
    }
}

YДмΔќʃʀï→ГC← 10-22-2007 • 19:41:52

Note: This has to do with a RfC for Angel David. YДмΔќʃʀï→ГC← 10-22-2007 • 19:45:36
I'm confused about what you're trying to achieve - you want to stop someone from making userspace edits without their consent? You do know that you can't edit someone else's monobook.js and even if you could it would be trivial to disable? — Matt Eason (Talk • Contribs) 20:41, 22 October 2007 (UTC)
Sorry, ignore the above - I've just read the talk page discussions — Matt Eason (Talk • Contribs) 20:46, 22 October 2007 (UTC)
I don't get it- what talk page? I gather that this is a self-accountability sort of thing.. my advice is that you'll need to use document.cookie to track things --ffroth 21:11, 22 October 2007 (UTC)
It is almost always inadvisable to try to apply a technical solution to a non-technical problem. Friday (talk) 21:14, 22 October 2007 (UTC)
Wouldn't I just log him out whenever he edited his userspace? Why not just check his contribs? We're trying to prevent him from using his userspace for his own good. Check around with his contribs, the RfC may still be going on. Any ideas on how to stop him from clicking edit on his page w/js?YДмΔќʃʀï→ГC← 10-23-2007 • 01:39:24
LOL now that's creative. Use javascript to refuse to load the edit monobook.js page, heh. This is such a bad idea though, you'll never be able to come up with a solution he can't bypass, and why would he consent anyway? --ffroth 02:41, 23 October 2007 (UTC)
He could just disable javascript. You'd have to do a server-side lockout if anything. Even then he could just make a new account. Not a solution. The only sensible way that I can think of is to make the ban and then police it if he violates it (get him kicked off for good), or something like that. Even that is not a simple technical thing and never has been. Also, your alert() line is malformed—it ends the string and then continues it again. Gotta remove the extra quotation mark and parentheses. --24.147.86.187 23:56, 23 October 2007 (UTC)

[edit] I want to defrag my computer the OLD FASHIONED WAY

Hello, I remember back in the day, defragmenting meant that there would be that awesome MS-DOS program where there were a bunch of rectangles and it would literally show the file pieces being read and written. WHERE IS THAT NOW??? Right now I am defragmenting my laptop and it is boring as hell just to watch a static screen. HOW DO I BRING THAT BACK???? —Preceding unsigned comment added by 71.141.142.51 (talk) 19:46, 22 October 2007 (UTC)

HEY SORRY ABOUT THAT IT SAID WIKIPEDIA EXPERIENCING TECHINCAL DIFFICULTIES —Preceding unsigned comment added by 71.141.142.51 (talk) 20:01, 22 October 2007 (UTC)

It wouldn't work for NTFS.. --ffroth 21:14, 22 October 2007 (UTC)
Windows' degragmenter has a mode that displays the clusters and such in a similar fashion. It was never as exciting as you seem to think... -- Consumed Crustacean (talk) 04:26, 23 October 2007 (UTC)
I do seem to remember last month blindly inputing lines of junk into MS-DOS the other month, and when I did it did that at startup every time, each time taking four hours. It has something to do with the chkdsk command (check disk) YДмΔќʃʀï→ГC← 10-23-2007 • 19:27:50
That's checking the disk for errors, though, not defragmenting it. Anyway, as Consumed Crustacean says, watching a disk being defragmented under Win95/98 feels a lot like watching the biggest and most boring game of solitaire ever, and only marginally more intellectually stimulating than watching paint dry. Besides, doesn't the defragmenter on WinXP at least still have a kind of "stripe" display showing what it's doing? —Ilmari Karonen (talk) 14:58, 27 October 2007 (UTC)
What DID happen to the old-style degfrag? Even in windows, it used to show me a big box of rectangles - now it's a bar with bands similar to bittorrent's display. I coulda sworn it changed sometime in the middle of my WinXP use - a service pack? Or am I just mistakenly remembering my desktop which had 2000 well into the XP era? Kuronue | Talk 19:51, 28 October 2007 (UTC)

[edit] Antivirus Software

Two questions:

1) If I buy Norton 360, do I have to pay an annual subscription fee on top of the cost of the software?

2) In your opinion, which offers better protection: Norton 360 or the free version of McAfee provided by AOL (which, as far as I know, is the complete version of McAfee)? Or are they just about equally effective?

Thank you!--El aprendelenguas 22:48, 22 October 2007 (UTC)

Personally I recommend people go with AVG Free or Avast, both of which are free and are used by computer-savvy people all over the world. Norton 360 is really a bundle of products—anti-virus, anti-spyware (free alternative: SpyBot), and a firewall (Windows XP and I presume Vista already have their own built-in firewalls). In my experience Norton products often result in severe problems—major bugs, major slow-downs, even crashes and corrupt hard disks. I have no idea if Norton 360 does this but personally I stopped trusting the company with my data a long time ago. Anything provided free by AOL I would be pretty suspicious of, as they don't exactly have a great track record either. If you want my advice for avoiding viruses: use Firefox not IE; use Thunderbird not Outlook Express; make sure your firewall is enabled; make sure you have anti-virus (AVG) and anti-spyware (SpyBot) software installed; don't run anything you don't have a good reason to trust; don't run things that people send you unless you were already expecting them (if you have doubts, just ask the sender) even if you know who sent it; make sure your automatic updates are enabled. Two of those steps require you to be a responsible computer user and be careful about what type of code you let execute on your machine, the rest just require installing programs, checking settings, or avoiding programs with notorious security flaws. If you did these things, you would probably be fine even in the worst case scenarios. --24.147.86.187 23:24, 22 October 2007 (UTC)
Mcaffee suxor. Use NOD32 or Kaspersky if you simply must pay, or AVG Free if not. Steer clear of clamwin --ffroth 01:22, 23 October 2007 (UTC)
Mcafee is an improvement over Norton, though that's not saying much. Kaspersky (pirated, modified) is what trojan/worm writers use to secure systems they've infected, since they know it works. Practice common-computer-sense and you won't need to use Anti-virus at all. -- Consumed Crustacean (talk) 04:34, 23 October 2007 (UTC)
Re: common-sense, yes and no. Yes in the sense that you won't purposefully execute malicious code. No in the sense that programs you use may contain vulnerabilities that you do not know about, which may allow malicious code to be executed remotely. Even non-Microsoft programs have their bugs and their possibility of buffer-overrides, they just haven't been exploited much since their marketshare is lower in most cases. I think anyone with a Windows box in particular should have anti-virus regardless of their common sense, because you never know when that thing's going to turn out to have a major door left open in the back. --24.147.86.187 23:21, 23 October 2007 (UTC)