Wikipedia:Reference desk/Archives/Computing/2007 October 14

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October 14

Component Video to DVI or VGA

I have a high quality monitor for my computer that has DVI and VGA inputs. I'd like to buy an adapter so that I can use he monitor as a display for my xbox 360, using the standard high definition component cables. Any ideas? It really needs to have no lag. —Preceding unsigned comment added by 71.195.124.101 (talk) 04:18, 14 October 2007 (UTC)

There are xbox 360 to vga cables produced by microsoft and third parties - that would be an additional purchase though..

Alternatively the monitor might understand a RGB component signal through the vga input (this is by no means guaranteed) - you would need to wire the component cables to a vga plug (see VGA connector) and the monitor would need to support "sync on green", and be receptive to signals at the frequency that the component video is output on.

I don't recommend messing about with soldering though..

I'd really recommend buying a xbox vga cable - that will work perfectly (if you have an xbox 360 with hdmi you could use a hdmi cable to connect to the dvi port (if you have one and a hdmi-dvi adaptor))

Finally here's a link http://ww.google.co.uk/search?hl=en&q=xbox+360+vga+cable&meta= price in the uk is less than £20 new for one make... —Preceding unsigned comment added by 87.102.19.106 (talk) 04:30, 14 October 2007 (UTC)

I will guarantee that the bought vga cables will be as 'good as perfect'87.102.19.106 04:32, 14 October 2007 (UTC)

GNU Scientific Library question

Resolved

per post to my talk page Algebraist 17:13, 14 October 2007 (UTC)

Dear Wikipedians:

While using the GNU Scientific Library I came upon the following interesting problem while using its Level 2 BLAS interface:

There is a function to compute Ax, where A is a matrix and x is a column vector (and the number of columns in A is equal to number of rows in x). However, the function to compute x^TA, where T denotes the transpose operator, x is a column vector and the number of rows in A is equal to the number of rows in x, is entirely missing from Level 2 BLAS. In fact, there seems to be no way of calculating this other than going to full-blown Level 3 BLAS with x modeled as an 1 by n matrix.

I really don't want to use Level 3 BLAS unless I have to due to performance penalties. And I can't believe that the designers of GSL had overlooked this issue when designing the level 2 BLAS routines. So I am wondering if I have missed anything or is there a specific reason why x^TA type of calculation is missing from level 2 BLAS, even though it's also vector-matrix multiplication.

Thanks.

74.12.197.100 05:11, 14 October 2007 (UTC)

Is x^TA=(A^Tx)^T of use, or is easy transposing not available? Algebraist 08:30, 14 October 2007 (UTC)

I'd ask the same question. Besides, I wonder why this task would even require BLAS. Couldn't this computation be handled by an appropriate loop in your C program? If you have an optimizing compiler, it should create efficient code for such a straightforward task. EdJohnston 17:28, 14 October 2007 (UTC)

Soundclips not playing

So I have a new computer. And on this computer, when I click on a sound clip link on in particular (I don't know any other instances, but I'm sure they exist) allmusic.com, my browser a) follows the link to a blank page and b) doesn't play anything. What is going on, and how can I fix it? Windows XP. I have realplayer installed but undefaulted for everything, quicktime, vlc, and itunes. I didn't enable quicktime to automatically make certain MIME types or whatever playable when it asked. Because my favorite default player is VLC, which plays everything. I'm using firefox 2.0 because some of my addons don't work with 3.0. Hope some of that helps. This is getting annoying, and I'd love it if somebody could clear this up for me. Thanks, Sasha 140.247.236.59 06:19, 14 October 2007 (UTC)

Right-click the link and hit Save Link As... and save it somewhere. That should clear it up. NASCAR Fan24^{(radio me!)} 15:37, 14 October 2007 (UTC)

Thanks, but are there any more permanent solutions? Why is this happening anyway? 140.247.43.7 23:31, 14 October 2007 (UTC)

• When I follow a link to a media file and it opens a blank window, it's usually because right afterwards it loads my mediaplayer to take on the selected file. Either you have a big file that loads slowly when you select it, or your mediaplayer doesn't kick in. Are you sure the file you're trying to watch/listen to is Realplayer compatible? Do you have all the codecs? - Mgm|^(talk) 09:03, 17 October 2007 (UTC)

Well it doesn't even give me a "you need to download certain codecs" message. It just loads a blank page and then stops without loading anything else. Nothing pops up. The way you described it used to happen on my old computer. But nothing whatsoever happens here apart from the opening of a new page. And I've got more than just realplayer. And trying to save the link does nothing. The link just saves itself as an unplayable dll file. Weird. I don't get it. Any other suggestions? 140.247.237.95 23:27, 17 October 2007 (UTC)

Laptop cameras

So I just got a laptop that I love (Thinkpad T60p)that doesn't have a camera built in. And I am beginning to regret it. And I was wondering if it's at all possible to have somebody install one at the top. There's even a little slit that makes no sense up where there might be a camera. And above this slit is an image etched in that might suggest that there's supposed to be some (nonexistant) light up there. Maybe a camera. Am I dreaming this? Does my computer actually have a camera? if not, what's the slit, and can I replace it with a video camera if I bring my computer to a shop one day? Thanks, 140.247.236.59 06:30, 14 October 2007 (UTC)

Perhaps you should have bought an AppleMac, the laptop has a built-in camera. —Preceding unsigned comment added by 88.111.33.45 (talk) 09:07, 14 October 2007 (UTC)

Lots of laptops have integrated cameras these days, not just MacBooks. --24.147.86.187 14:25, 14 October 2007 (UTC)

The mac laptops are called Macbooks, and no it probably will not be possible. I have one of the mentioned Macbooks, and it's really not that special, only useful n occasion. —Preceding unsigned comment added by 71.195.124.101 (talk) 14:22, 14 October 2007 (UTC)

The Thinkpad T60p series does allow for integrated cameras, so you're probably not making things up when you think it may have a slot for one. All the same, if you didn't buy a model with a camera in it, it is probably unlikely that you could add one in later. Even if you could add one in later, the labor charges would be steep—taking apart the monitor part of a laptop is often very difficult and much more expensive than messing around with the part under the keys. Why not just buy an external USB webcam? They are quite small and not very expensive (the top of the line models are around $100; you can get pretty good ones for $20-50—again, all of this is much cheaper than trying to get an integrated camera installed would be), and for the times you want to use a camera you can have it right at hand. --24.147.86.187 14:25, 14 October 2007 (UTC)

This option does not sound the best advise at first, but on second thought, if one can carry wireless mice with the notebook all the time, why not a webcam too? Of course, an integrated one would be more convenient but you should definitely give a thought to the USB 'webcameras' too. To go off a tangent, I do not really know about BlueTooth connected webcams though. I think they might have privacy issues. --Kushal^{Click me!} write to me 16:59, 14 October 2007 (UTC)

I think someone asked about that a few days ago.. as far as I could tell there are no bluetooth webcams; there's just not enough bandwidth. And bluetooth has such a pathetic range that there would be no problem with privacy --froth^t 20:01, 16 October 2007 (UTC)

Are you sure there's no light there? Try hitting Fn + PgUp. Now do you see the light? --froth^t 17:08, 14 October 2007 (UTC)

Ah. The light exists. I'll look into external webcams. Thanks, all. 140.247.43.7 23:30, 14 October 2007 (UTC)

_THERE_ _ARE_ _FOUR_ _LIGHTS_!!! --froth^t 00:17, 15 October 2007 (UTC)

LOL. JIP | Talk 17:54, 17 October 2007 (UTC)

It looks like this thread has ended and the OP satisfied. I am staring at the screen like Dr. Watson as I have no clue what the solution was. Did the OP have a built-in camera? If no, what is the light? If yes, why is (s)he looking for an external one? --Kushal^t 01:10, 15 October 2007 (UTC)

To answer your question, there is no built-in camera, but there is a built-in (and fairly fucking useless) light where a Macbook or other built-in-camera computers might have a camera. So no solution, but at least I understand what the slot is for, and I can now know that I have to go searching for an external camera. 140.247.43.7 02:36, 15 October 2007 (UTC)

Thanks. --Kushal^t 23:45, 15 October 2007 (UTC)

I like the light. Webcams are useless- the web is text and that's the magic of the internet and internet communication. The LED lets you make a cool little lightshow by rapidly hitting a key.. how cool is that? :O It's a good idea anyway, for people who aren't comfortable with the keyboard (hard to see how that's possible with the wonderful thinkpad keyboard <3). The light is at just the perfect angle that it spills over the whole keyboard but doesn't cause glare on the screen. Also, nice signature kushal :P --froth^t 19:48, 16 October 2007 (UTC)

the web is text - Allow me to introduce you to YouTube. ;) -- 68.156.149.62 21:25, 16 October 2007 (UTC)

Holy crap I feel like richard stallman here, all the halfwit hobby hardware hackers taking over where the golden age of programming in the MIT AI lab left off. Only now it's the golden age of the internet -usenet- being taken over by youtube as the de facto social framework. Yes youtube is successful and popular and accessible (cough, hobby hardware hacking, cough) but usenet was superior. We still see the last echoes of the text era in the great bastions of IRC and web forums (wikis not so much, they tend to collect a ton of multimedia), which are still vastly more respectable than youtube, flickr, or *shudder* social networking sites --froth^t 20:53, 17 October 2007 (UTC)

Burns ... What about Internet and Internet2? And yes, the web was made for text^{[citation needed]}. But you are right too, the Internet has evolved quite a bit since its creation inception. —Preceding unsigned comment added by Kushal one (talk • contribs) 22:39, 16 October 2007 (UTC)

GUI Programming reference?

I'm trying to build a simple game using sprites like in old NES games, except that my ideal conception has the sprites on hex's, not invisible "squares". Can someone provide a link to some sort of tutorial or reference to enable me to do this? I consider myself an intermediate programmer, but at "behind the scenes" tasks; I have very little experience with GUI and game programming, and consider the subject intimidating. Help?

Deshi no Shi 16:05, 14 October 2007 (UTC)

For that kind of thing, I wouldn't use the GUI toolkits - they aren't designed for games. You would be better off learning some OpenGL programming techniques. Making your sprites be little textured polygons. This harnesses the power of the graphics card to it's utmost and gives you the performance to animate vast numbers of sprites at very little CPU cost. http://www.opengl.org is probably the best place to start looking for online learning materials and books. There are a ton of example programs you can start working with. You would use a library such as http://freeglut.sourceforge.net to cleanly handle opening and closing windows, keyboard and mouse I/O. SteveBaker 16:31, 14 October 2007 (UTC)

OpenGL really is the deep end of the pool. Even for experienced C++ programmers, OpenGL can be very intimidating (although libraries that wrap around it like GLUT or SDL can help a bit, and SDL adds DirectX support). What's your level of experience in regular programming? (Which language do you use, what sort of programs are you used to writing?). The standard GUI libraries may not be optimized for games, but if you're only interested in NES-like sprite games, it's not going to make a hell of a difference. On modern hardware you can make those games in Flash (Actionscript) and they'll run just fine. And you'll write a game in a tenth of the time in actionscript/python/whatever, compared to figuring out OpenGL. A final advantage to actionscript (or languages that compile to something that can be played in a flash player, like HaXe) is that people can play it from their web browser, so you'll increase your potential audience.

Also, what do you mean by 'hex's'? Do you mean you want the playing field to be a mesh of hexagons instead of squares? Perhaps you could describe a bit more clearly what the game will look like. Is it going to be a side scroller, or a top-down perspective game like Zelda (on the gameboy anyway). That would give us a better idea of what you'll need to implement your idea. risk 16:54, 14 October 2007 (UTC)

I'm good with C++ and Python, about to the point that I can program everything I need EXCEPT for the graphical elements. In fact, I could probably write what I wanted this game to be using ASCII. And what I mean by "hex's" is, yes, the playing field would be a mesh of hexagons instead of squares. It would be a top-down perspective like Zelda, but not so much "scrolling" -- my vision is for it to be akin to a board-game. --Deshi no Shi 20:23, 14 October 2007 (UTC)

If you are really making a very simple game, there are many free game-making toolkits out there which will handle all of the sprite and memory management issues as well as make GUIs far more easy to deal with. I have used Adventure Game Studio which despite the name is quite flexible in the types of games one can make and is quite straightforward. There are others which specialize in other types of games too, like RPG Maker. There is an entire category of such things as Category:Game creation software. I like AGS because if you already have some experience scripting and programming, you can use its own internal scripting language (which is fairly generic) to do some pretty useful and powerful things with a minimum of having to muck around with actually dealing with sprites on anything other than a graphical and programmatic level. In any case, such programs are probably a good way to start one's first game, as otherwise the possibility of getting very bogged down very quickly is pretty high, and the likelihood of getting frustrated and giving up is pretty high. Whichever one you go with, make sure its terms of use and redistribution meet your satisfaction. --24.147.86.187 16:50, 14 October 2007 (UTC)

Thanks, this was exactly the kind of information I was looking for.

Deshi no Shi 16:52, 14 October 2007 (UTC)

• Pygame is popular with Python fans. --Sean 18:36, 14 October 2007 (UTC)

Prevent reaching BIOS

Is there anyway a computer Administrator can prevent users from reaching the BIOS on a Windows machine? Acceptable 18:08, 14 October 2007 (UTC)

Thank Goodness, No ... unless you make it physically impossible to take the computer apart and impossible to hot reboot it. --Kushal^{Click me!} write to me 18:26, 14 October 2007 (UTC)

Well, there's always a way in, of course. But you can protect the BIOS with a password. The user would then have to open the machine up and move a jumper on the motherboard in order to reset the BIOS to it's non-protected state. So you lock the case so it can't be opened, and you're safe unless the user knows how to pick a lock (which shouldn't be too difficult for those flimsy ones they put on computer cases) or brings a saw. risk 18:35, 14 October 2007 (UTC)

Can a Pentium 4 be overclocked through the BIOS? Acceptable 18:33, 14 October 2007 (UTC)

That depends on the motherboard. Most motherboards these days do have that functionality. risk 18:35, 14 October 2007 (UTC)

Ah ok, thanks for your help. Acceptable 18:40, 14 October 2007 (UTC)

You could take off the keyboard - that will make it hard to get into the BIOS. Also if you flashed your own special BIOS code with no keyboard escape you will get an inaccessible one, but still you could reflash it again with a good version, or replace the EEPROM. Graeme Bartlett 21:03, 14 October 2007 (UTC)

Best way is to set up a hard drive password through the BIOS. Then you have to replace the logic in the physical hard drive to get access to the data. --froth^t 23:10, 14 October 2007 (UTC)

Or use something like PGP Desktop's "whole disk encryption", which puts a password on the drive at bootup, and the entire drive is encrypted so there's no real way around it. Arakunem 00:22, 15 October 2007 (UTC)

Hard Drive question

I think my harddrive has a few problems with it. For example, when I downloaded something that is clearly 700 mbs, when I chck the properties on my harddrive, it registers as about 1.2 gigs. This happens with almost every file.

From the My Computer screen, when I right click for the hard drive space, it says that I have used 70 GBs worth of space. However, when I access the drive, select all, and right click properties, it says the total on the hard drive is about 40 GBs. I have my settings to show all hidden files, so I'm wondering where all that extra space went? Is this a common problem? I don't remember having this problem with any of the other computers I owned before.

If it is a problem, how do I fix it, short of getting a new hard drive.

Thanks 129.100.207.33 18:20, 14 October 2007 (UTC)

Does it say the following? Size: 700 MB Size on disk: 1.2 GB Kushal --Kushal^{Click me!} write to me 18:25, 14 October 2007 (UTC)

No it doesn't. I also forgot to mention that I've done all the defrag, bad sector check and empty recycle bin stuff. For the life of me I can't figure it out. —Preceding unsigned comment added by 129.100.207.33 (talk) 18:30, 14 October 2007 (UTC)

I don't know it This is related to your question or not, but Some types of CD-ROM images wind up being greater than 700Mb. I don't fully understand why.--APL 19:29, 14 October 2007 (UTC)

When you download the file with two different browsers, does the same thing happen for both of them? Are you downloading from a browser or is it some p2p program? If so, does it only happen with that program, or with other ones as well? risk 22:02, 14 October 2007 (UTC)

Well, the easiest way to assess "where is my disk space going" is to use a space visualizer like SequoiaView. Warning: All of your porn will be easily findable by anyone curious! ;-) --24.147.86.187 22:31, 14 October 2007 (UTC)

To the OP, did you try the SequiaView application? --Kushal^t 22:35, 16 October 2007 (UTC)

How much overclocking..

How much can a Pentium 4, CD and C2D CPU's be overclocked to? For example: can I overclocked a C2D to say, 1 million ghz, and purposely blow it up? Acceptable 19:01, 14 October 2007 (UTC)

The clock signal from the motherboard is very slow (a 133mhz FSB is common); the only reason your CPU can run so fast is because it has a multiplier circuit. The speed of the gates in the multiplier circuit places a very practical limit on the maximum clock rate at which the processor will run, but long before that, the processor will become unstable (for example flags not getting activated in time for the next instruction, like cmp/je) and be inoperable but it may in fact catastrophically crash through overheating. My computer overheats all the time (laptop >.>) but the screen just goes black and I have to turn it on again. I'm sure the thermal stress is destroying my hardware (not like I can do anything about it) but when you're dealing with high multipliers you can literally melt your processor into a boiling pool of silicon! This has resulted in radical solutions like liquid nitrogen cooling.. see overclocking --froth^t 19:57, 14 October 2007 (UTC)

So if I did want to sabotage my computer, could I set the clock signal to a ridiculous speed like 3 ghz and set the multiplier to a ridiculous amount like 300x? Or will the computer not let me? Acceptable 20:15, 14 October 2007 (UTC)

Some CPU's have a limit on how high you can clock them. If you want to take your anger out on your computer, bang the hard-drive on your desk a couple of times. That should break it. NASCAR Fan24^{(radio me!)} 21:54, 14 October 2007 (UTC)

Even if you could, it would probably fail instantly without causing permanent damage --froth^t 23:00, 14 October 2007 (UTC)

Its commonly accepted ^{[citation needed]} that if you want to sabotage your computer, the fastest way would be with a hammer. --Kushal^t 21:52, 14 October 2007 (UTC)

This may be OR but I think a can of Cherry Coke poured into the ventilation grill would be faster. SteveBaker 17:15, 16 October 2007 (UTC)

Someone should try it! =P --Kushal^t 22:35, 16 October 2007 (UTC)

Dropping it in a vat of feces or snot would ruin it most effectively IMO. Even if I could fix it I would never even try --froth^t 20:55, 17 October 2007 (UTC)

is it safe????

is it safe for me to let my pet rats run around inside my computer??? will it get to warm for them in there? —Preceding unsigned comment added by 68.210.23.83 (talk) 21:27, 14 October 2007 (UTC)

Eh, no. There is a 100% chance they will either get shocked or they will chew off some vital wire. Oh, come on. You know the answer to this. Please stop posting inappropriate questions to the Reference Desk. NASCAR Fan24^{(radio me!)} 21:37, 14 October 2007 (UTC)

Maybe you could have a box for your rats right beside your computer casing (preferably not attached) that could give an illusion that your rats are inside the casing. --Kushal^t 21:50, 14 October 2007 (UTC)

Only with a specially-made case would this be something like a good idea. --24.147.86.187 22:28, 14 October 2007 (UTC)

Oh wow that case is just wat i needed. thanx and nascar man ur mean i wuz just asking a question —Preceding unsigned comment added by Dlo2012 (talk • contribs) 20:32, 15 October 2007 (UTC)

That case is insane... · AndonicO ^Talk 01:05, 16 October 2007 (UTC)

..ly awesome. I can't believe you only get 3 geek points for buying a $150 item, is this a fluke? --froth^t 02:31, 16 October 2007 (UTC)

Nobody who has ever owned a hamster would ever consider that case a remotely reasonable proposition! My son's hamster had a maze of tubes like that (you can buy them without the computer case in any petstore) - the little beast spent it's entire existance packing every inch of every tube in sight with woodshavings from the floor of the main cage - then peeing and poohing throughout the entire area. This means that a couple of times a week you have to dismantle the entire thing - wash it all out and start again. That's a big pain with a regular cage setup - but with that thing, you'd have to pull your entire PC apart every time - and you just KNOW that every third time you do that, you'll get hamster poop in your CPU fan...yeah - if you ever wondered what would happen if the shit hit the fan... SteveBaker 02:44, 16 October 2007 (UTC)

He did say rats, is that any different? Maybe it was best just to let them run loose in there ;D --froth^t 03:34, 16 October 2007 (UTC)

Actually, the tubes in the ThinkGeek case are too small for a rat. They say: "gerbil, hamster or mouse". SteveBaker 17:13, 16 October 2007 (UTC)

Also, pee based water cooling? Sounds like something the bio-tech Octospiders would do. (from Gentry Lee's space opera sequels to Rendezvous with Rama) --froth^t 03:50, 16 October 2007 (UTC)

I would say just leave the two things (CPU casing and rat home) separate. Could save some tears if something happens (to the rat). --Kushal^t 22:34, 16 October 2007 (UTC)

recovering deleted items

I deleted powerpoint off of a lexar thumb drive. How can I recover it?24.94.10.157 22:58, 14 October 2007 (UTC)

I honestly don't know if you can rescue a file off of a flash drive - it may be like a floppy disk where the data leaves forever after deleting it. Undeletion provides a link to FilesLost.com, perhaps you may want to try that. It claims in its FAQ that it can recover files deleted off of thumb drives. NASCAR Fan24^{(radio me!)} 23:05, 14 October 2007 (UTC)

TestDisk, Photorec, dd_rescue? And to NASCAR Fan24, even on a floppy disk, a filesystem delete operation will simply remove the pointer to the blocks of the deleted file, so the data will remain until a filesystem operation performs an overwrite on those blocks. Splintercellguy 00:15, 15 October 2007 (UTC)

Why did you have PowerPoint on a flashdrive anyway?Mix Lord 01:16, 16 October 2007 (UTC)

They probably meant "A PowerPoint file," not the application. Never underestimate the power of the internet to mangle English grammar. --24.147.86.187 02:48, 16 October 2007 (UTC)

Or stupidity *rolls eyes* Hanlon's razor --froth^t 03:35, 16 October 2007 (UTC)