Wikipedia:Reference desk/Archives/Computing/2007 October 21

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October 21

video bug

Yesterday I bought a new Envision monitor that has two input jacks: DVI, and an old-style DB (I don't know what that interface is called). My Mac Mini has a DVI output jack, and came with an adapter to the other standard, which I used up to now. With the DVI cable, my new monitor frequently blinks out for a sec or two. (With the other cable+adapter that problem goes away, but the colors are not as pretty.) Any idea where the problem is most likely to be? —Tamfang 00:19, 21 October 2007 (UTC)

You could try replacing the DVI cable, it could have a contact error. Also, can you find out an event that's usually triggerring the blinks? – b_jonas 08:31, 23 October 2007 (UTC)

After a day or two of looking at one-pixel horizontal jitter from the old-style interface, I put the DVI cable back and, what d'ya know, no blinks. Musta been a contact flaw as you say. If there was an event trigger, it was subtle. —Tamfang 19:19, 23 October 2007 (UTC)

Spoke too soon. Yesterday when I started a DVD the picture first went noisy and then blinked out. Later I played three or four other DVDs without incident. —Tamfang 20:17, 24 October 2007 (UTC)

Operating system breakdown?

Hi. Does anyone know what the breakdown is of operating systems? What percentage of people in the US (or world) use XP, 2000, Linux, etc? Thanx. —Preceding unsigned comment added by Notahoo (talk • contribs) 00:44, 21 October 2007 (UTC)

Is that a homework question? I do not understand the first question. Does it mean a crash (computing)?

As for the second question, try the articles on Microsoft Windows and Linux. What OS people use is a difficult question. There can only be estimates and that too will probably be based on estimates from the number of computers and assuming an arbitrary number (maybe close to one or two) of users per computer.

Hope that helps, regards, Kushal --Kushal^t 12:51, 21 October 2007 (UTC)

The OP just means breakdown as in a statistical breakdown — Matt Eason ^{(Talk • Contribs)} 18:13, 21 October 2007 (UTC)

Sorry for this stupid question, Matt, but what is a statistical breakdown? How does it relate here? --Kushal^t 19:49, 21 October 2007 (UTC)

As in, "X % of people use Windows, while Y % use a Linux variant, Z % run MacOS X..." etc. It's a common expression in the USA to call a numerical division of something a "breakdown," as you're "breaking it (down) into pieces." See also Pie chart. ;) -- Kesh 20:08, 21 October 2007 (UTC)

By way of example only... I think the OP wanted to know 65% of users use XP, 15% use Vista, 10% use Mac OS, 10% use Linux or somesuch distribution. Astronaut 20:07, 21 October 2007 (UTC)

Breakdown in the context the OP used it just means subdividing something into more specific parts, so a pie chart which answered this question could be titled "Breakdown of computer users by operating system", with each pie segment representing the percentage of XP users, OS X users etc. If you've ever done any web authoring you might like this time breakdown of modern web design.

Notahoo - you might find this page useful. Bear in mind that their statistics are based on web users, so people without internet access will be under-represented. It will also be significantly biased towards personal/office computers - a huge amount of servers run Linux. Netcraft might have some data on OS statistics for web servers if you have a dig around. — Matt Eason ^{(Talk • Contribs)} 20:35, 21 October 2007 (UTC)

Perl and Python with Apache on Debian

I have Apache2 and PHP5 installed on my laptop (running Debian 4) and I'm trying to get Python and Perl working with Apache as well. However I'm having quite a bit of trouble. The modules are downloaded and installed However, attempting to execute any perl files results in a 403 error, despite the script being chmodded to 755. Trying to execute a python script results in an Internal Service Error, even though the code was taken from http://www.modpython.org/python10/

I've tried a number of solutions from all over the web, but still cannot get it working. Unfortunately, there seems to be no one tutorial that covers all the steps from start to finish, like there is with PHP, which is actually quite a bit easier to install. Any help would be greatly appreciated.

Dlong 02:50, 21 October 2007 (UTC)

I had bad experiences getting mod_python to work with apache - most problems arose due to ABI mismatches (the mod_python binary had been compiled against an apache that was sufficiently different to what I actually had installed). Eventually I gave up with packages and compiled mod_python myself (and as this expected a file generated during the apache build process, and which wasn't present in the Apache binary dist package I had installed, I ended up also compiling apache myself too). If you're getting all your packages from the Debian repositories then this shouldn't happen, however. -- Finlay McWalter | Talk 02:59, 21 October 2007 (UTC)

Always read your log files. Every time a client gets an error message, a line is written to /var/log/apache2/error.log or /var/log/apache/error.log which tells what rule was violated. --tcsetattr (talk / contribs) 03:00, 21 October 2007 (UTC)

I'd be interested in why you're trying to use mod_perl and mod_python in the first place. There's no particular reason why you shouldn't, but you don't actually need them to use Perl or Python on your web site — and, as you've noticed, getting them to work right isn't always trivial. The simplest way, by far, to run Perl or Python scripts on your website is simply via CGI. True, it's not the most efficient or versatile way there is, but for most purposes it's more than sufficient, at least unless you're running a high-traffic site like Slashdot (which uses mod_perl) or Wikipedia. If you need more speed than plain old CGI can provide, or if you have other reasons for valuing persistence, you can also go for something like FastCGI, SCGI or SpeedyCGI (a.k.a. PersistentPerl), which provide a very convenient middle ground between plain CGI and full-blown Apache integration, with many of the advantages of both. Personally, I have particularly good experiences of SpeedyCGI: it's what we've settled on at work to run our Perl-based web application framework. —Ilmari Karonen (talk) 12:46, 21 October 2007 (UTC)

Possibilities

Would it be possible (n any amount of time) to build a DNA based computer with full AI capability?NewDevilWiki 03:58, 21 October 2007 (UTC)

Real AI has nothing to do with DNA, it has to do with brain structure. You could theoretically create DNA in the lab and have it somehow be "read" in order to drive a computer, just using it as a biological hard disk, but this is way off. -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 04:33, 21 October 2007 (UTC)

Depending on how you define computer, you are a DNA based computer with full AI. You're a full-on Turing machine, executing algorithms all day and night. --Oskar 06:33, 21 October 2007 (UTC)

Of course, you could consider a the brain of a human being to be an "intelligent DNA-based computer" - but that doesn't count in terms of the question because the 'A' in 'AI' stands for 'Artificial' - and human intelligence isn't artificial. SteveBaker 22:18, 21 October 2007 (UTC)

We are just beginning to examine the possibilities for using biological molecules for computing - and some simple experiments using DNA have been done. However, we're a very long way from a full-up working computer - and it's not entirely clear that such a machine would ever be a commercial possibility because large, biological molecules are fairly fragile.

As for the AI part of the question - the term AI is a little problematic - it's meaning has changed over the years. There was a time when playing chess at grand-master level was considered to be an AI problem - but now we've solved that, we no longer thing of playing grand-master chess to be an AI problem. As fast as we solve problems that were once thought to be AI, the idea that they ever required 'intelligence' goes away. Right now, I suppose that passing the Turing test would be considered by many to be proof of a working AI - but people who are working on AI are frequently very unhappy about that judgement.

Since we can't (yet) produce DNA computers - and we can't (yet) produce Artificially Intelligent computers - there is no immediate prospect of making a DNA-based computer with full AI. However, it's not impossible in principle so it may happen someday. But please don't go away with the idea that somehow a computer could become intelligent because it were based on DNA. Remember, there are very few DNA-based plants and animals that we'd consider "intelligent" - so DNA does not imply intelligence!

SteveBaker 22:18, 21 October 2007 (UTC)

Volume level, mute, etc....display on screen.

Hi folks. I used to have Windows 98SE and I could see my volume changes, and mute/unmute onscreen when I changed them. I could even change colors. Can the same things be done with Windows XP? If so, how? Thank you. Dave 64.230.233.222 04:30, 21 October 2007 (UTC)

My understanding is that Windows does NOT provide such functionality itself. The visuals you see in 98SE are likely from your keyboard drivers. Hopefully drivers exist for your keyboard in XP. In all likelihood, you'll get the same functionality with XP, but you might not get OSD (on screen display) for volume up/down/mute. Since you could change colors of the OSD, it likely means it's definitely some kind of custom software that came with your keyboard. I would suggest you contact your keyboard manufacturer, or visit their web site, to see if they have Windows XP drivers and software that can provide the same functionality in Windows XP. --Silvaran 05:04, 21 October 2007 (UTC)

I`ll try that. Thanks very much for the prompt reply. Dave 64.230.233.222 05:08, 21 October 2007 (UTC)

Quick follow-up: First, I left out a few, perhaps key, pieces of info. I suppose I should have mentioned that my keyboard was from an 'old' Compaq Presario 7479. Secondly, I really liked that/this keyboard and so attached it to this 'new' Dell Dimension 4300. Thirdly, the Dell`s hard-drive went bad and I have installed the Compaq`s drive. The Compaq`s drive had Windows 98SE on it but now has Windows XP. I went to Compaq`s website and indeed found Windows XP software for said keyboard. I attempted to download and install the keyboard drivers. About 2/3 to 3/4 of the way through the install an error came up: It couldn`t find a certain Compaq file. I instructed the install to continue anyway. There was/were no noticeable change(s). To make a long story short,(too late already, I fear)nothing happened. I, right away, and just to be safe, returned to the previous drivers. Hopefully I suffer no long term problems. Just wanted to let you know. Thanks for helping me with this. Dave 64.230.233.222 15:37, 21 October 2007 (UTC)

Semantic book search

I want to make a search function in a program wherein you only need to enter the ISBN (or something) and all the metadata (title, author, publisher, etc.) of some book is automatically filled in. I figure that there has to be some library database online where you can get all that stuff in an XML-file or something, right? I mean, I could use Google Book Search or something and simply parse the results for the data, but that seems like more trouble than it's worth. --Oskar 06:10, 21 October 2007 (UTC)

I'm not sure I understand what exactly you want, if you want a totally offline database that would be huge, if you just want something you can put the ISBN in and get that info use this works very well, grabbed a few books off my shelf to confirm it had them, 0-671-80815-x comes up correctly as Ripley's Believe It or Not, Book of Americana, and 0-939798-34-4 comes up as my Saxon High School Calc book(no ribs about me keeping my high school books, the school got rid of all their old texts in 1999 and I grabbed a copy of each, I know I am weird. ;)). You can do it without the dashes also. Dureo 06:52, 21 October 2007 (UTC)

That site also has a remote access API which should allow you to build its functionality into your own programs. --24.147.86.187 14:28, 21 October 2007 (UTC)

Apple Mac G4 System x / TV

Can anyone advise me please on the type/name of the cable required to link the red/yellow/white connections on the TV to the computer and which 'hole' is used on the computer. (The manuals NEVER tell you the basics!). Thanks.--88.110.33.229 06:10, 21 October 2007 (UTC)

I think this is what you need, should get confirmation though, I personally have never tried. Dureo 06:45, 21 October 2007 (UTC)

Also it says it is for a G5, but works with a G4. Dureo 06:46, 21 October 2007 (UTC)

Thanks, but no thanks! It connects with the computer OK but there is no way that the broad end will connect with the TV. Any other ides will be welcome please.--88.110.33.229 07:22, 21 October 2007 (UTC) —Preceding unsigned comment added by 88.110.33.229 (talk) 07:22, 21 October 2007 (UTC)

"The video output port supports VGA, S-Video, and Composite video out." You'd have to use one of those cables off the tv to connect to the tv side, seems the S-video wins out if you have that type of connector on the TV, You can also use RCA_connectors with an additional adaptor if that is all the TV has. Dureo 07:46, 21 October 2007 (UTC)

Actually, that is the correct adapter. That "broad end" actually has two plugs: the yellow Composite video-out, and an S-Video-out connector. You also need a simple headphone-to-RCA audio adapter for the sound, and plug that into the headphone jack on the computer. You can pick the audio adapter up at your local Radio Shack or audio/video store for cheap, along with the composite cable (if you don't already have one). -- Kesh 20:32, 21 October 2007 (UTC)

Image conversion

How does one convert an image.png to image.svg ? - Kittybrewster ☎ 08:49, 21 October 2007 (UTC)

It's very difficult - if not impossible.87.102.16.28 09:37, 21 October 2007 (UTC)

However it's not impossible see Raster to vector - look for something suitable there or use that term as a search term.87.102.16.28 09:38, 21 October 2007 (UTC)

It's very difficult if not impossible currently for a computer programme to convert it satisfactorily, but if you do it manually you can do it to an extent (don't even attempt doing it for real photos, or you'll hit barriers related to fractals on objects). --antilived^{T | C | G} 10:33, 21 October 2007 (UTC)

Use Inkscape. I believe you know what an SVG is and what its uses are. Unless it is a simple thing like a chessboard that you want to convert, expect to be disappointed. --Kushal^t 12:42, 21 October 2007 (UTC)

Depending on the graphic and the type of application, you may also want to consider potrace. --71.162.241.172 14:16, 21 October 2007 (UTC)

Usually "converting" means "re-drawing" in this case. Simple mechanical conversion never really looks the same even if your original image is very vector-graphic-like in appearance. Vector tracing software usually can't even handle simple circles and straight lines and have them come out looking right. --24.147.86.187 14:29, 21 October 2007 (UTC)

The OP did not say what the application was; the result of automatic conversion might just work for her(?) purpose. Plus, once converted, the resulting image can be fixed by post-editing. --71.162.241.172 15:43, 21 October 2007 (UTC)

Personally I have found it always easier to redraw. The angles are never right at all in automatically done things and they are usually a total mess of nodes, impossible to edit with any precision. Better to just draw it over again (or just trace it)—it'll likely take about the same amount of time that post-editing would, but look better and be better coded anyway. --24.147.86.187 00:52, 22 October 2007 (UTC)

The image in question is Image:Lord-red.png - Kittybrewster ☎ 15:56, 21 October 2007 (UTC)

That image is derived from Image:Lord.png, which was created by User:Steifer. It might be worth contacting him, either here or on the Commons, to ask if he can upload an SVG version. — Matt Eason ^{(Talk • Contribs)} 16:03, 21 October 2007 (UTC)

Needs to be redrawn; the dithering on that will NOT translate well into SVG. There are people on here (I forget the name of the particular Wikiproject) who can re-draw things for you. It would not take someone experienced in Inkscape very long to do something like that. -24.147.86.187 00:52, 22 October 2007 (UTC)

Couldn't you just open it in the GIMP and then export it as an SVG file?Mix Lord 01:22, 23 October 2007 (UTC)

windows vista probs (E-Mail address removed)

I recently purchased windows vista basic home edition. As administrator, after logging on, I am now greeted with a green screen and a cursor!!! There are no icons or toolbars.Other account users are not experiencing any difficulties. Is there any way I can recover my info or am I doomed to start again??? If I am , how do I make administrative and security changes???

Please help...Desperate

cozmic —Preceding unsigned comment added by 211.28.247.159 (talk) 09:36, 21 October 2007 (UTC)

^{Email address removed — Dureo 09:51, 21 October 2007 (UTC)}

Its not the best way but under Windows XP (and possibly under Vista too), you can go to C: and documents and settings and then to the person's folder. If possible copy this person's (in this case administrator)'s documents and settings for backup. Don't jump into it yet, you might find better solutions in the coming days. Stay tuned. --Kushal^t 12:36, 21 October 2007 (UTC)

If doing the above, try from another account with administrator privileges. User Access Control feature may not let you back up your data otherwise. BTW, do you have another account with administrator privileges? --Kushal^t 12:39, 21 October 2007 (UTC)

In Vista the path will be C:\Users\[your user name] — Matt Eason ^{(Talk • Contribs)} 12:52, 21 October 2007 (UTC)

Thanks for the correction. I hope the OP has another account with administrator privileges. --Kushal^t 13:05, 21 October 2007 (UTC)

Semantic markup

In web programming, what is that? 203.214.77.25 10:34, 21 October 2007 (UTC)

See Markup language#Descriptive markup. Essentially it's marking up parts of the document according to what they are, rather than what they should look like. — Matt Eason ^{(Talk • Contribs)} 11:13, 21 October 2007 (UTC)

Hard disk

I had a hard disk of 40GB from Western Digital Company. The jumper of this hard disk was on the last pair of pins from the left i.e. the first pair of pins from the left. Totally there were five pins. Recently, I bought a second hard disk of 200 GB and I fitted it in into the CPU. A data bus previously attached my old hard disk with something at the bottom of the CPU. There was another port on the same bus. I connected this port to the new hard disk. I removed the jumper of the new hard disk and kept it safely in my drawer. This new hard disk was from Seagate company. But when I started my pc there was a boot disk failure. It also said that there was a media test failure and it asked me to check the cable. It asked me to enter the system disk and press enter. I just pressed enter. But the same message kept displaying repeatedly. I asked my friend and he found a solution. He asked me to take the jumper of the old hard disk and fit it into the third pair of pins. I did. The computer started well. I formatted the new disk, assigned it a drive letter, and aslo copied data to it. And then I restarted the system. But the same media test failure came. The same disk boot failure and "enter system disk" message was displayed. But when I pressed enter the computer booted normally. Since then,whenever I start my pc the same message is displayed but when I press enter the pc boots normally. Can anyone explain this? Is it harmful for my pc? I would be very grateful to you for your help. —Preceding unsigned comment added by 59.89.21.254 (talk) 10:37, 21 October 2007 (UTC)

Guessing which cables and jumper settings are needed is not a good idea. Both Western Digital and Seagate provide product support (including installation and jumper settings) for their products on their official sites. The support information will help you select the correct connections and jumper settings for your required configuration. Of course, you might still have a hardware problem somewhere causing the media failure. Astronaut 12:16, 21 October 2007 (UTC)

Seagate and WD drives have a slightly different jumper arrangement. Graeme Bartlett 01:55, 22 October 2007 (UTC)

You should check the BIOS to make sure that the boot order is correct. It might be trying to boot from the non-system disc first (i.e. the one without Windows installed). It should be set to boot from your 40 Gig drive. --Seans Potato Business 16:25, 22 October 2007 (UTC)

airport express doesnt work

I'm 20 feet, as the crow flies, from an unprotected and working airport express which I can detect but not connect. My computer is wifi enabled, and normally does connect, just not to this one. I know it works because it has worked for other people before.--Jorgenssen 14:31, 21 October 2007 (UTC)

Have you been able to connect to other wifi stations in the past with that computer? (Just trying to narrow down where the problem may be.) --24.147.86.187 16:03, 21 October 2007 (UTC)

Perhaps the Airport Express base station has MAC filtering enabled and your computer isn't on the list of acceptable MAC addresses?

Atlant 17:07, 21 October 2007 (UTC)

Yes and no.--Jorgenssen 17:22, 21 October 2007 (UTC)

or, can you make the range bigger? —Preceding unsigned comment added by Jorgenssen (talk • contribs) 21:30, 21 October 2007 (UTC)

Yes and no. The range on the Airport Express can't be directly increased, but its position in the home/apartement/whatever will influence its range. Materials in between your computer and the base station will provide some interference. Also, the antenna & positioning on your own computer will affect the signal strength as well. -- Kesh 21:44, 21 October 2007 (UTC)

You CAN put it in the focus of a parabolic dish and point it where you want the signal to be going, but then that's not exactly practical for most uses. --antilived^{T | C | G} 01:49, 22 October 2007 (UTC)

Neither computer nor base station have ariels its in a very central position..parabolic dish in the shape of say, a skydish, eg a shallow sauce pan?--Jorgenssen 08:53, 22 October 2007 (UTC) also, it seems to cut out all the time unless its encryptd. —Preceding unsigned comment added by Jorgenssen (talk • contribs) 08:59, 22 October 2007 (UTC)

If you have a Sky dish lying around somewhere in theory you can put your airport extreme base station slightly above the little plastic thing (the antenna) and point it to where your computer is to create a directional antenna and boost signal strength. A frying pan would also work, but I haven't tested any of the things I said and I'm just saying this from a theoretical view point. --antilived^{T | C | G} 09:10, 22 October 2007 (UTC)

I take it that dents the signal a bit on the opposiite side of the dish? —Preceding unsigned comment added by Jorgenssen (talk • contribs) 13:45, 22 October 2007 (UTC) --Jorgenssen 13:47, 22 October 2007 (UTC)

Yes it would reduce the signal in the area that's blocked by the reflector. You can't magically raise the power in one direction without increasing the transmission power or reducing it in other directions. --antilived^{T | C | G} 05:37, 23 October 2007 (UTC)

Or maybe there is open source firmware which lets you boost the signal further than mac stuff lets you...Jorgenssen 13:49, 22 October 2007 (UTC)

Locked out of Word

I am locked out of my word program, I can get into it but can't do anything including typing. Could it be that I haven't registered my Office Suite yet or did I just press the wrong keys? —Preceding unsigned comment added by 67.127.97.65 (talk) 16:17, 21 October 2007 (UTC)

You don't have to register Word, but you do have to authenticate it. However if you are not authenticated it will tell you so. So something else might be wrong.

I recommend, in this order: 1. running a full virus scan while in safe mode; 2. running a full spyware scan while in safe mode; 3. if those don't turn up anything, find the file "Normal.dot" (the default Word file template) and delete it (it will automatically regenerate); 4. if all that fails, uninstall and reinstall. --24.147.86.187 16:44, 21 October 2007 (UTC)

(edit conflict) If you don't activate Office it'll go into 'reduced functionality mode', which means you can open and read your documents but you can't edit them. Microsoft has information about activation here — Matt Eason ^{(Talk • Contribs)} 16:48, 21 October 2007 (UTC)

If your version of Office does not say that you are in reduced functionality mode, try the steps that User:24.147.86.187 suggested. If that does not work, use OpenOffice.org as a temporary solution. If you need assistance with the all-new Microsoft OpenXML file format and compatibility issues with OpenOffice.org, or have any other questions, feel free to stop by the reference desk again. I will be more than happy to hear back from you.

PS: We have made several assumptions in the process of suggesting you. Some of these might not be warranted. Please let us know if any of our assumptions are wrong. (For example, you might be using StarOffice Writer and called it Word which we assumed to be Microsoft Office Word 2007.)

Regards,

--Kushal^t 19:45, 21 October 2007 (UTC)

LCD screen failing

My PC LCD screen seems to be dying. I switched on the screen the other day and noticed a block of dead pixels had suddenly appeared. A block about a 1/2 centimetre square had gone totally black when it should be showing white. I tried to "massage" the pixels back to life but this just seemed to spread the damaged area beyond the original boundaries. Most of the damaged area is now showing blue (indicating dead RG pixels) while there is some cyan (dead R) and magenta (dead G) spotting. The weird thing is that the damage seems to be spreading by itself horizontally and turning more and more of the screen black in little horizontal strips. It almost looks like the screen is suffering from a virus (not a computer virus) with the infection spreading. Has anyone come across anything like this before? Jooler 19:19, 21 October 2007 (UTC)

Sounds like you created an LCD fractal I had the same problem on a laptop a long long time ago, learned that the rubbing on the screen made it worse (this was when lcd's first came out new, new technology) it didn't spread much beyond that though. I would check with the manufacturer for their dead pixel return policy if it is a newer monitor. Chuck it if it is older, they cost more than they are worth to have the lcd's fixed unless it is a cell phone, and you can do that yourself quite easily. Dureo 00:12, 22 October 2007 (UTC)