Wikipedia:Reference desk/Archives/Computing/2010 January 29

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January 29

micro-SIM

It looks like that any 3-year-old can use a pair of scissors to make a micro SIM card from an ordinary SIM card.

http://apcmag.com/images/micro-sim.jpg

Do they put the electric circuits under the "fingers"? -- Toytoy (talk) 01:18, 29 January 2010 (UTC)

As you can see in this photo - the actual circuit is a really tiny bit of silicon. It's about the size of the central contact patch on the smart card. SteveBaker (talk) 05:53, 29 January 2010 (UTC)

It appears to me that what you are calling "fingers" are the electrical contacts. The size of those are limited by the ability to get an acceptable connection between the card and the reader. That has nothing much to do with the circuit used for memory storage. -- kainaw™ 17:57, 29 January 2010 (UTC)

Regular expression - write n at nth match

Is there a way to use sed in order to replace the n-th match of a pattern with the number n? E.g. if the pattern is "xyz" and the file's content is "abcabcxyzuioxyzasdf" then the output should be "abcabc0uio1asdf". Thanks in advance. Icek (talk) 06:09, 29 January 2010 (UTC)

sed is Turing-complete, so it can be done, but not easily, I think. For what it's worth, you can do it in Perl like this: perl -pe 'BEGIN{$n=0} s/xyz/$n++/eg' -- BenRG (talk) 08:18, 29 January 2010 (UTC)

Careful there: do you mean the nth match within the same line, or the nth match in the whole file? If it's the second meaning, that Perl code is correct (and can be shortened by removing the BEGIN{$n=0} part). For the first meaning, where the count resets for each line, put $n=0; without a BEGIN. Either way this must be far easier than any solution involving sed, which does not have numeric variables. --Anonymous, 00:11 UTC, January 30, 2010.

I don't know how you could replace a match with an arbitrary string using only POSIX regex. Using a programing language of course would work, but I don't think it's possible with a typical regex alone. There may be some work around I don't know about in either of those, but if there is I don't know it if it's part of the general spec. Keep in mind that sed and grep use a better (as in more efficient) regex engine when it comes to non-recursive patterns than does perl and nearly every other reg ex out there. Shadowjams (talk) 11:58, 29 January 2010 (UTC)

The stupid way would be to have a sed script that looked like

s/xyz/0/
s/xyz/1/
s/xyz/2/
#...

...since it replaces from left to right and (without g) will replace one at a time. Is that good enough? (It won't be if it's possible for there to be confusion between replacements and things to replace, like if "xyz" is really "000"; you can do some sort of byte stuffing to work around that.) You could even run sed in a loop; write out each iteration and stop when two are the same. --Tardis (talk) 17:25, 29 January 2010 (UTC)

Where to get a capture card?

Any of you gamers out there making videos with capture cards or what not, could you text me back and tell me where you can get a capture card? Can you get them in Australia? Originally posted in article namespace by Jyejonah (talk) 10:21, 29 January 2010 (UTC)

Do you mean capturing video from a video game console, or capturing what happens on your PC's screen while you play a PC game? If the latter, I recommend FRAPS. If the former, lots of PC video cards have a video-in option so you can use them as a capture card. Be sure you choose a card that supports the video signal that you want to capture — PAL or an HD signal (presumably 720p; and make sure the cabling inputs match what's coming out of your console, so you don't get an HDMI input board only to find your console has no HDMI-out video connector). There are also USB devices that capture video; I expect these to be worse in quality than a solution built into your graphics card — though I don't have a specific recommendation; I'd search for "video capture" at Newegg (I know, it's a USA retailer, but the user reviews are great for locating which product you want to start actually shopping for) if you can't find any actual recommendations in this thread. Comet Tuttle (talk) 18:20, 29 January 2010 (UTC)

Laptop Problem

If I put my laptop on hibernate after connection to the WiFi in my college, when I return home I can't connect to my home network without a reboot. Getting DNS problem and also it says something about keyports. My usual solution is to sign into MSN and use the inbuilt repair with MSN to connect. But it is getting to be a pain now any suggestions? Thanks. BigDunc 11:28, 29 January 2010 (UTC)

I had similar trouble with a Centrino laptop from IBM. The issue turned out to be a faulty ACPI driver (not the wireless card driver! Go figure). The "hibernate" feature in particular caused a variety of improper hardware shutdowns, which the system did not know how to recover from on wakeup. This caused instability, blue-screen crashes, and generally required a regular reboot to fix.

Unfortunately, without very specific details about your laptop make, model, including the wireless card type, drivers, and operating system, we can't really begin to diagnose what's causing your trouble. The conventional approach is "update all your drivers," in the hope that this problem was fixed in a newer version. Nimur (talk) 18:33, 29 January 2010 (UTC)

In Windows XP and Vista, I think you can right-click on the wireless icon and choose "repair" (somewhat fewer clicks are needed in XP, I think). This would still be a rather inelegant fix, but somewhat simpler than what you are doing now. In the same vein is opening the command shell and typing "ipconfig/release" followed by "ipconfig/renew". Just some suggestions, I'd try the things suggested in the previous reply first... Jørgen (talk) 19:13, 29 January 2010 (UTC)

Cyberarticle 4.364

Does anyone know where I can get this last-freeware-version without using Torrent please? All the sites I can find that may host it also appear to be in Chinese or Japanese. I am looking for 4.364, not 4.363. Thanks 78.149.174.141 (talk) 12:39, 29 January 2010 (UTC)

Why not use BitTorrent? Get a copy of uTorrent or similar, and download it that way. Dedicated servers aren't cheap, not everything gets hosted in perpetuity. —ShadowRanger ^(talk|stalk) 15:02, 29 January 2010 (UTC)

Screensaver or program showing progression of night and day across the atlas

Where can I find one of these please? Similar things I've seen before show a world map which is light where daylight is, and dark where night is. The dark/light border is like a "S" shaped wave. 78.149.174.141 (talk) 12:43, 29 January 2010 (UTC)

Pick one. --LarryMac | Talk 14:37, 29 January 2010 (UTC)

Just providing a link to Google is not a helpful answer to the question, nor is it clever. I should have added that I'm looking for a freeware one. 78.149.174.141 (talk) 14:56, 29 January 2010 (UTC)

(ec)The link in his response lists several such screensavers in the first few lines. How exactly is that not helpful? Do you expect someone to test and evaluate each of them for you? —ShadowRanger ^(talk|stalk) 14:58, 29 January 2010 (UTC)

I cannot see any. I have been through every link on the first page. Most of the links are to irrelevant webpages that mostly look like automatic compilations of other web material. After going through two or three clicks through to other websites I did find one freeware program but which is not a screensaver, and which does not work. 78.149.174.141 (talk) 15:11, 29 January 2010 (UTC)

Following up based on your addition to your comment: Several of the links are shareware, which is better than nothing. Sometimes you have to pay for software you like though; someone does have to write it after all. —ShadowRanger ^(talk|stalk) 15:00, 29 January 2010 (UTC)

No need to be so aggressive, gentlemen. I was hoping that someone who had used one or knew of one could suggest one they were familiar with. If every question was answered with a Google link, what would be the point of this Reference Desk? If you do not want to be helpful but just macho, then let's consider this question cancelled. 78.149.174.141 (talk) 15:08, 29 January 2010 (UTC)

Then you should have asked "Can someone recommend ..." or "Has anyone used ..." rather than "Where can I find ...". Of course we can't help you if you don't explain what you really want. Gandalf61 (talk) 15:21, 29 January 2010 (UTC)

78, you are the only one that has leveled any criticism in this thread. Comet Tuttle (talk) 20:16, 29 January 2010 (UTC)

To be honest I couldn't find a useful one in the links myself - there was http://3d2f.com/programs/2-995-earthview-download.shtml which uses a globe not an atlas I think they want something like this - http://www.iris.edu/seismon/html/june15th.html - maybe someone could at least suggest better search terms? (is there a technical name for this shadow - that would help) How about http://www.brothersoft.com/earthwatcher-64155.html (free) or http://www.freemap.com/geoscreensav.htm $59 - but do they work?or http://www.osxplanet.com/ 87.102.67.84 (talk) 12:49, 30 January 2010 (UTC)

I use http://www.mapmaker.com/shadowfacts/v65/index.htm 's sunzip which has a freeware version. -- SGBailey (talk) 23:11, 30 January 2010 (UTC)

http://hewgill.com/xearth/
http://images.google.com/images?q=xearth ¦ Reisio (talk) 23:35, 30 January 2010 (UTC)

Automating downloading a page after a menu choice

There is a webpage with a drop-down menu. The menu offers twenty or thirty choices. After each selection of the menu, a page of information is shown, which I want to save to disk. What would be the easiest no-cost way to automate the downloading of these pages please? The problem is getting past the drop-down menu and going through all its choices. Actually there are three menus right next to each other, but I think going through just one menu gets all the information. Thanks. 78.149.174.141 (talk) 15:20, 29 January 2010 (UTC)

If you look at the page source, you might be able to figure out what logic it uses to determine the page to visit, then use wget or the like to iteratively retrieve each page. This would require some basic HTML and scripting knowledge though. Menus can be implemented many different ways, so it's not trivial to pull every page linked from one menu. —ShadowRanger ^(talk|stalk) 17:45, 29 January 2010 (UTC)

Also, while I've never used it, you might try DownThemAll. It might be a bit overzealous (you may get more than you want), but it should be easier than the manual solution I suggested. I'm a scripting geek, so I think everything is solved better with Perl one-liners, but I recognize that not everyone is in the same boat with me. —ShadowRanger ^(talk|stalk) 17:48, 29 January 2010 (UTC)

how do I use a networked printer

Okay, this is really dumb. I use dsl with a router, it has yellow lan lines and stuff, but also wireless. If I just plug in one of the yellow lan lines into the networked printer, will I suddenly be able to print from my netbook which is connected to the same router on wifi? Or, do I have to configure it or something? I'm using windows 7 on the netbook, and the printer is an hp. color laserjet... thanks for as much information as you can give me. 84.153.238.207 (talk) 16:28, 29 January 2010 (UTC)

All the computers (and networked printers, and any other Internet-ready gadgets) "behind" the router should be able to see each other, whether you're connecting to the router via cables or via the wireless connection, without having to configure anything special on the router. Comet Tuttle (talk) 17:26, 29 January 2010 (UTC)

thanks! 84.153.213.154 (talk) 09:52, 30 January 2010 (UTC)

IE7 peculiarity

There was a discussion regarding Template:Collapsible list which died out a couple months ago, but never came to a solution. Is there anyone that can figure out why the show/hide link displays differently in IE7 than every other browser? Assuming it hasn't expired yet, this page shows the screenshots of the different browsers. Thanks, MrKIA11 (talk) 16:46, 29 January 2010 (UTC)

Have you tried asking this question at the Village Pump "Technical" page? That page is frequented by Wikipedia hackers, and is much more likely to get you a response than this Reference Desk, which does deal with computer related questions but isn't Wikipedia-specific. Comet Tuttle (talk) 17:27, 29 January 2010 (UTC)

Yeah, I also posted there, just trying to reach a wider audience. MrKIA11 (talk) 17:39, 29 January 2010 (UTC)

I would hazard a guess that Internet Explorer is an awful browser. —Preceding unsigned comment added by 82.43.89.14 (talk) 22:35, 29 January 2010 (UTC)

template talk:collapsible list#Overhang_section_break^* ¦ Reisio (talk) 09:58, 30 January 2010 (UTC)

Graphics card question

My mother is buying a new computer. She has figured out what she wants, but the company she is buying from (Dell) has a number of graphics card options, and she doesn't really know which one to pick. I don't either, but I suspect they are all overkill for her needs. Her most graphically-intensive activities are to edit large photos in Photoshop, occasionally watch DVDs, browses the web and watches YouTube. She does not play games or do anything with 3D (and she is the only one who will ever use this computer). Is there any reason to go beyond the basic option here? Is she going to notice any kind of real improvement?

• nVidia GeForce 310 512MB GDDR3 [Included in Price]
• nVidia GeForce GTS 240 1024MB [add $130]
• ATI Radeon HD 5770 1GB GDDR5 [add $180]
• nVidia GeForce GTX 260 1792MB [add $230]
• ATI Radeon HD 5870 1GB GDDR5 [add $330]

I've had a hard time researching this because all of the discussions about the merits of said video cards are about their abilities as gaming cards or 3D rendering cards, which are irrelevant for this purpose. She won't be overclocking, obviously. Does she really need more than the basic card? All I know is that it seems much more powerful than my current card, and I'm able to edit photos, movies, what have you without much difficulty, but I haven't bought PC parts in ages. Any thoughts? (And spare me the "Dell hell" lecture and any related ones... I know, but it's what she wants to do.) --Mr.98 (talk) 17:57, 29 January 2010 (UTC)

The baseline card should be *more* than sufficient. A card half that powerful would do for what she is doing; unless she takes up 3d gaming, CAD work, or video editing, it will be more than enough. —ShadowRanger ^(talk|stalk) 18:01, 29 January 2010 (UTC)

OK, that's what I thought. She was scared because the Dell site helpfully explains that if you have the low-end card, all you can do is Instant Messaging and E-mail, which I am sure is not true, but of course she wanted me to double-check. --Mr.98 (talk) 18:10, 29 January 2010 (UTC)

Of course the Dell site says that. Dell is trying to up sell. The only thing she does that requires even a modicum of power is Photoshop (and running the OS), but any of the cards listed will kick Photoshop's ass, metaphorically speaking. She should make sure she has at least a couple gigs of RAM, and going up to 3 or 4 won't hurt (newer OSes are RAM hogs, and programs like Photoshop and Lightroom often benefit in responsiveness when provided additional RAM to cache images), but I can make a guarantee that no photo editing software worth the name released in the next five years (and more than likely, the next ten) will even remotely tax the resources of the "low end" graphics card you describe. —ShadowRanger ^(talk|stalk) 18:15, 29 January 2010 (UTC)

Does the GeForce 310 actually use a 300-series GPU? It seems like it does not, and uses a G80 processor. More details at GeForce 300 Series. This is an unfortunate and confusing bit of marketing-ese. (I almost choked on some coffee over here seeing a GeForce 300 OEM that cost less than a GTS240!) Nimur (talk) 18:50, 29 January 2010 (UTC)

If that's the case, it would make it a bit more power hungry for the performance, but not underpowered. I'm running an 8800GTX (768 MB of RAM) at home and can run Fallout 3 (and several other graphics intensive games) without issue. 98's mother will do just fine, G80 core or no. —ShadowRanger ^(talk|stalk) 19:30, 29 January 2010 (UTC)

If your assessment of her needs is correct then even the cheapest of those systems is probably a hundred times more powerful than she needs. I would stick with an nVidia board because their drivers are better. I'd avoid anything by Intel because they are junk. Aside from that, aim for the low price point. SteveBaker (talk) 05:15, 30 January 2010 (UTC)

General Purpose GPU

I heard that graphics cards are super powerful processors. I have a bog standard graphics card that came with the computer, and except for basic display of the desktop and firefox etc I don't use it for graphics (games, movies etc). Can I harness it's power for computing tasks? —Preceding unsigned comment added by 82.43.89.14 (talk) 19:41, 29 January 2010 (UTC)

See our article on GPGPU. Short answer: If your graphics card is old (more than two or three years) it's likely not useful. And even if it is, the programs have to be coded to take advantage of it. You can't just shift processing from CPU to GPU for arbitrary programs. —ShadowRanger ^(talk|stalk) 19:48, 29 January 2010 (UTC)

For example, when I'm not gaming, I run Folding@Home on my GPU. It produces results for the project that are (according to the points given by the project) roughly 10-15x more useful to the project than that produced by a single core on a CPU. The results are different (GPUs are good at floating point calculations, CPUs are good at integer calculations), but sometimes it's useful to get the faster but somewhat less precise results a GPU can give. —ShadowRanger ^(talk|stalk) 19:54, 29 January 2010 (UTC)

Thanks for the links. So I can't just wave a magic wand and double my computers processing power, seemed to good to be true :( —Preceding unsigned comment added by 82.43.89.14 (talk) 22:34, 29 January 2010 (UTC)

No, you have to go to great lengths to find useful applications for the GPGPU outside of the realm of technical computing (CAD, numerical physics, and so on). The GPGPU is not very useful for things like web surfing - although regular GPU acceleration can be useful for things like accelerated web-video decompression, 3D maps like those on Bing Maps, etc. Nimur (talk) 23:01, 29 January 2010 (UTC)

The GPU is a very strange beast. It contains a heck of a lot of extremely simple computers that all have to run the same program at the exact same time and (more or less) all run the programs together in lockstep. These little computers are crazy-fast. This makes them very useful for doing bulk processing work where some simple operation has to be done a heck of a lot of times with slightly different data each time. That's why they are so good at doing graphics where there are maybe a million pixels that need to be drawn, all with essentially the same algorithm but with slightly different data at each point. The GPU can draw graphics hundreds of times faster than the CPU could possibly hope to do. That also makes them good for things like movie compressing or weather forcasting. However, these little machines don't have much memory each, they have no access to the hard drive or the network or even the mouse and keyboard, and they find it hard to communicate with each other. They also have their own fairly weird programming languages. So you can't run something like a browser on them (although you could use them to draw pictures on behalf of the browser). It all depends on what you want to do.

If you are a programmer and you're (say) writing a chess playing program - then you could probably do some restructuring of the software that tests out every possible move that you and your opponent can make for the next few moves of the game and get a massive speedup by using the GPU. But as an average non-programmer, you can only get out what the people who wrote your software designed their product to do. Right now, not many of them use the GPU for anything other than graphics.

SteveBaker (talk) 05:11, 30 January 2010 (UTC)

Thank you everyone for the informative answers! :) —Preceding unsigned comment added by 82.43.89.14 (talk) 12:48, 30 January 2010 (UTC)