Wikipedia:Reference desk/Archives/Computing/2008 April 12

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April 12

Instant Messengers

I have grown somewhat frustrated with the use of instant messengers. I really thought they were good for instant communication, however, i have many people on various buddy lists, that are seemingly logged in all the time, and never say anything when you IM them. Why do some people log in to a messenger service and proceed to never say anything? —Preceding unsigned comment added by 69.210.140.222 (talk) 03:26, 12 April 2008 (UTC)

I can think of many reasons:

1) They are logged into the IM service automatically when they do something else. For example, whenever you go online on AOL, it starts AIM.

2) They stepped away from the computer.

3) They are busy talking with somebody else.

4) They don't know you're trying to contact them. On some IM systems, the notice that somebody is trying to IM them can pop up underneath another window or off the edge of the screen. There may be an audible sound, too, but they may have the speakers turned off or the sound from some other application may interfere with the IM beep.

5) They just don't want to talk with you now. StuRat (talk) 03:31, 12 April 2008 (UTC)

Those may be the case, however, it seems as if some people NEVER EVER say anything, So what would be the point to log on to a messenger and never say a thing? —Preceding unsigned comment added by 69.210.140.222 (talk) 03:46, 12 April 2008 (UTC)

Some people also forget to log out of clients or leave their computers on (as well as forget to log out of clients) overnight to do things. x42bn6 Talk Mess 04:38, 12 April 2008 (UTC)

Another thing I've noticed is that some IM clients are installed by default and set to login automatically every time the computer boots. For example, when I'm doing backups, maintenance, etc on my neice's PC, the messages start arriving pretty much as soon as I start her PC. Most of the time I ignore it but I'll eventually set the status to "busy" if there are too many. Unfortunately, some of her friends seem incapable of considering that "busy" really does mean busy. So, maybe the person on the other end is not who you think it is and is trying hard to ignore your incessant need to chat, or maybe they just don't know how to switch the damn thing off. Astronaut (talk) 11:39, 12 April 2008 (UTC)

A lot of people just leave it on all the time (since a lot of people leave the computer on all day) and update their away messages to let people know that they're busy doing work or watching tv, out at dinner, etc. This way people don't get lots of phone calls while they're busy doing something else. The next thing will be setting auto-responses when you get txt messages. Plus this is something more common to younger people which is akin to older people having a constant need to be connected by phone, e-mail, blackberry, etc. The world is getting much smaller. --MATTblah24 (talk) 03:39, 15 April 2008 (UTC)

Linux system requirements

In general, what are the system requirements for the Linux 2.4.* and 2.6.* kernels (in terms of, among other specs, hard drive space, RAM and clock speed)? I know that the size of the kernel can change considerably depending upon the configuration at compile-time, but a general estimate (if possible) would be appreciated nonetheless. Thanks, --Iamunknown 06:00, 12 April 2008 (UTC)

A CPU of one of the architectures listed here [1]. Other than that there is seriously no way at all to give you an estimate. There's a good reason people repeat that over and over. A Nintendo DS has a 67MHz ARM processor and can run Linux, and the current fastest supercomputer in the world [2] has something like 200,000 CPUs running SUSE Linux Enterprise Server. If you asked about the requirements of a particular distro we might be able to help out more, though many of them tend to be pretty flexible. -- Consumed Crustacean (talk) 06:33, 12 April 2008 (UTC)

Ok, thanks for the answer. I'm a bit of a Linux noob, so I guess I'll need more experience before I can ask a more focused question (and by then I might have answered it anyways :-)) Cheers, --Iamunknown 18:07, 12 April 2008 (UTC)

The Linux kernel can run on any computer that you can purchase. You are more likely asking for the system requirements of a window display manager such as GNOME or KDE. It is very common for people to confuse those with the kernel because in Windows there isn't much of a way to run the "Windows kernel" separate from the "Windows display manager". -- kainaw™ 01:09, 13 April 2008 (UTC)

Not true. Linux requires that the computer have a MMU. Every consumer-targeted system sold in the past 20 years or so has one, but many embedded systems don't. --Carnildo (talk) 20:08, 14 April 2008 (UTC)

Webcam Question

I have a webcam I bought recently for a new work project. The work project has taken a long time to get started, so I took the liberty of playing around with the webcam on MSN and putting stuff on YouTube, using certain effects. Unfortunately, I can't get it to go back to the default 'focus' setting. It is from "it.works". My girlfriend says all she can see is a blurred image. Does anyone know how to get the focus back? I've tried every setting I can find, so please only answer if you are familiar with this hardware. --ChokinBako (talk) 07:38, 12 April 2008 (UTC)

Does it have autofocus? If not try twisting the lens barrel (like you do back in the manual-focus camera days). --antilived^{T | C | G} 11:46, 12 April 2008 (UTC)

Typeable pdf.

i have a form on .doc format, i want to convert it to a type-able pdf format so that i can type on it!...can someone tell me how to do that???please! —Preceding unsigned comment added by 123.252.227.145 (talk) 09:02, 12 April 2008 (UTC)

As far as I know, it is not (yet) possible to create a fillable pdf form using Microsoft Office Word. You can use Adobe Acrobat standard/professional, Scribus or any Desktop publishing software. Sorry :( Kushal 10:57, 12 April 2008 (UTC)

I'm not sure I understand this - you have a .doc document (i.e., a Word document) and you want to convert it to PDF so you can type on it? Why can't you type on it in Word?
If you want to convert a Word document to PDF there are a number of options, one I use is called CutePDF Writer, which installs as a printer - when you 'print' to it it creates the output as a PDF. It's free and good. But then you need a program to type into the PDF with if that's your wont, which as I say I can't see why you wouldn't type into Word to start with. --jjron (talk) 16:12, 12 April 2008 (UTC)

squirrels

Is it safe to keep baby squirrel as a pet? —Preceding unsigned comment added by 59.95.245.179 (talk) 10:19, 12 April 2008 (UTC)

could we move this to the science desk? Kushal 10:59, 12 April 2008 (UTC)

Do you mind SQuirreL SQL Clients? Mr.K. (talk) 12:18, 12 April 2008 (UTC)

I don't think they are likely to kill anyone, but they don't seem to have the personality that makes for a proper pet. I'd expect to get bitten often. I also doubt if they can every be litter-box trained. StuRat (talk) 15:25, 12 April 2008 (UTC)

Right. It's generally not a good idea to keep wild animals as pets; there's a reason the number of animals used as pets as relatively small, and practically all of those have undergone years and years of artificial selection for better personalities (domestication). Additionally, you may want to consult local laws on owning animals—many places don't let you keep just any old animal on your property unless it is a farm or something like that. --Captain Ref Desk (talk) 15:28, 12 April 2008 (UTC)

I had a friend who had a pet squirrel of sorts. Their cat killed its mother and they looked after it, but over time it began to get aggressive and distant, until eventually it moved outdoors permanently and never let them get near it. It still occasionally taps on the back windows when it wants food. Think outside the box 17:55, 12 April 2008 (UTC)

Firefox 3 pretending to be Firefox 2

Hello, I have an issue with my recent upgrade to Firefox 3 - a certain secure website now refuses to let me log on. It was always fine with Firefox 2 which is listed on the "supported" list. Anyway I can get 3 to pretend to be 2? Like a "legacy" mode. Or any other workaround? Thanks. -90.203.189.60 (talk) 13:37, 12 April 2008 (UTC)

Well, one way is to change the user-agent to have it identify as Firefox 2 ("Mozilla/5.0 (Windows; U; Windows NT 5.1; es-ES; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13"). --Captain Ref Desk (talk) 15:40, 12 April 2008 (UTC)

Ah thank you - will give it a go! --90.203.189.60 (talk) 16:15, 12 April 2008 (UTC)

desperate

I desperately need to view a PDF on my iPod video, I would even stoop to taking screenshots of each page, cutting it up into one screenful of resolution each, and saving them as a stream of photos. How could I do this programmatically?

Ie, I'd like to go from

 _____
|1  2 |
|     |
|3  4 |
|     |
|_____|

  p1

to 4 photos. It could be 8 photos. Or 16. Or 32. As I said I'm DESPERATE.

Any help? THank you. —Preceding unsigned comment added by 79.122.53.15 (talk) 15:10, 12 April 2008 (UTC)

The way I would do this is with ImageMagick, convert the pdf into images. Then, you can convert the images into a video. --Rajah (talk) 20:11, 12 April 2008 (UTC)

I'm not sure if you still need help, but here's a quick run through.

1. Install ImageMagick
2. From the command line: convert originalPdf.pdf output.png (I'm using .png here for lossless compression, but .jpg or whatever is fine too.
   1. The resolution for this might not be the best at first, so you may want to try something like: convert -density 600x600 -resize 800x560 -quality 90 lc_pdf_overview_format.pdf lc_density.png
3. Now you will have one .png file for each page of the original .pdf

If you want to make out a movie out of those, please specify what type of movie you want to make. --Rajah (talk) 23:49, 12 April 2008 (UTC)

Hi, sorry about my late response. The problem is that your method gives one picture per page but iPod video is only like 320x230 or something so each page of the pdf should be "multiplexed" into several photos as I tried to illustrate with my crude ascii diagram above. any ideas? thank you. —Preceding unsigned comment added by 79.122.53.15 (talk) 02:01, 13 April 2008 (UTC)

A similar suggestion would be to use a JPG/PNG printer driver. Many printer drivers allow you to have less than one page per sheet, such as "one page on four sheets" (usually won't look at where the text is, but still). I use PDFCreator to "print" PDFs from any document (including PDFs from Acrobat sometimes), and that program also supports "print to JPG" or "print to PNG". Unfortunately I don't think that program has that functionality of splitting a page on multiple pages though. When you accomplish that I don't see why you would want to convert to video, doesn't most iPods support slide shows of pictures? Good luck! and let us know if you figured it out. Jørgen (talk) 08:34, 14 April 2008 (UTC)

CD DVD rom speed up

i have problem with the speed of my dvd rom. It takes my 1.30 hrs to write a dvd . Does any one know how to solve this problem. Please help. Please send your answer on (email removed). thankyou. —Preceding unsigned comment added by 220.224.69.192 (talk) 17:10, 12 April 2008 (UTC)

1. a DVD-ROM can't write to DVDs.
2. what is the speed written on the drive? (Example: 8X)
3. what software do you use? What programs are running when you write a DVD?
4. what speed is your computer's CPU?
5. how much data do you write?

--grawity ^{talk / PGP} 17:19, 12 April 2008 (UTC)

no it writes a dvd but it takes at least one and half hour although i use nero 7 and i have a dual core with 512 mb RAM.yes the speed is et to 8x. —Preceding unsigned comment added by 220.224.69.192 (talk) 17:22, 12 April 2008 (UTC) i have a laptop and no speed is written on the drive.When it was new it used to take 10 to 15 minutes but now it takes a lot of time —Preceding unsigned comment added by 220.224.69.192 (talk) 17:25, 12 April 2008 (UTC)

What programs are running when you write a DVD?

And please sign your replies with <nowiki>~~~~

--grawity ^{talk / PGP} 17:32, 12 April 2008 (UTC)

i dont run any programmes. I even disable sometimes norton to increase some speed.

What OS do you use? --grawity ^{talk / PGP} 17:52, 12 April 2008 (UTC)

i use windows xp media centre —Preceding unsigned comment added by 220.224.69.192 (talk) 17:54, 12 April 2008 (UTC)

Maybe the drive is still under warranty and you get it replaced? I can fill up a DVD in under 12 minutes with a (presumably 8x DVD-RW drive), AMD FX-60 (2.6GHz dual core), 3GB DDR RAM. If you only have 512MB RAM, you'll probably want to upgrade. Useight (talk) 18:02, 12 April 2008 (UTC)

na the warranty is over.I will update it. Thanks friend. —Preceding unsigned comment added by 220.224.69.192 (talk) 18:07, 12 April 2008 (UTC)

Are you writing DVD binary data or are you encoding video to the DVD? Encoding video to DV format from another format takes HOURS if the video is of any length. If you are just writing data it should go fast (15 minutes, tops). --Fastfission (talk) 20:06, 12 April 2008 (UTC)

Your software may allow you to change the write speed. Also, it may have options to perform a precheck before writing and verify data after writing, both of which will add to the time. StuRat (talk) 03:37, 13 April 2008 (UTC)

Most Windows PCs slow down after several months use. An accumulation of updates, spyware, viruses, and so on. More memory might help - it seems stupid to spend $700+ on a new computer for the sake of $100 of memory - but it might be better to first check you are free of malicious programs, you have the latest and greatest updates and service packs, and you have updated the necessary drivers. Delete the auto startup of unnecessary programs, services and those pesky update programs that hise in the system tray. Astronaut (talk) 09:35, 13 April 2008 (UTC)

That shouldn't affect how long it takes to burn a DVD, not on the scale he/she's talking about. My guess is that either 1. the DVD drive is broken, or 2. the OP doesn't really understand what it's doing (e.g. it is really encoding to DV video, not writing to DVD, that is slow). --Captain Ref Desk (talk) 16:41, 13 April 2008 (UTC)

It is likely that your drive is in PIO mode instead of DMA mode. This can happen almost at random (maybe because, just once, you put a scratched CD or DVD in the drive that it couldn't read). See these instructions for how to fix it, and a longer description of the problem. -- Coneslayer (talk) 14:26, 14 April 2008 (UTC)

What makes the hard disk tick?

What makes the ticking sound of a hard disk drive? Is it an intentional sound, to let you know it's accessing the disk, or just an inevitable mechanical noise? Is it the voice coil, the actuator, something else? Always wanted to know. Fritter (talk) 21:50, 12 April 2008 (UTC)

Hopefully it's just the sound of the header reading and/or writing. If it's making excessive sounds, you may want to back up your data. Useight (talk) 00:50, 13 April 2008 (UTC)

That's not quite an answer, as I implied I realize the sound occurs when "it's accessing the disk," i.e. reading or writing. I was wondering, physically, what causes the noise (and why some HDs are loud and others aren't). And I do back up my data; or I should say, a cron job does it for me -- I can't be trusted with something so important! Thanks for the feedback. Fritter (talk) 00:56, 13 April 2008 (UTC)

I think its the drive head's motor that makes the sound you describe when the computer is accessing the disk. The platter motor also makes sound, but its more of a constant hum. Rilak (talk) 06:23, 13 April 2008 (UTC)

An electromagnet moves the head rapidly in or out on the order of milliseconds. The quck twitch is the click as it jumps from track to track. Graeme Bartlett (talk) 12:48, 13 April 2008 (UTC)

Sound is a result of vibrating air molecules. My guess is that the arm is the most likely component to be disturbing enough air to make the tick sound. (Picture at Hard disk drive#Technology.) --- I just found this article which seems to agree it's the arm: What is the churning sound I hear from my hard drive whenever it is retrieving data? --Bavi H (talk) 00:58, 14 April 2008 (UTC)