Wikipedia:Reference desk/Archives/Computing/2007 June 17

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[edit] June 17

[edit] Electrical Schematic design software

I'm looking for a (preferibly free) program that can design and/or simulate a home electricity network. I prefer something very basic that's not bundled with all other CAD packages. All the ones I found on google do circuit boards, which I don't want. If there are multiple standards for scematic diagrams, I want the North American/U.S. standard. — Kjammer  ⌂ 00:53, 17 June 2007 (UTC)

Ummmm what do you mean by design/simulate a home electricity network? If you want a schematic/PCB creation programme, Eagle (program) is quite good, I've used it to build some PCB with that. --antilivedT | C | G 04:33, 17 June 2007 (UTC)
To be more specific, I am looking for a program that offers an easy way to draw Circuit diagrams whitout using paper, or a generic graphic drawing program. What I want is something that is not totally specific to PCBs, where I can map the electrical layout of a room (lightswitch, AC source, lights, junction boxes, etc.). Is this possible with EAGLE? I'm finding the product's documentation ambiguous/favoring PCBs. Thanks for your reply. — Kjammer  ⌂ 05:19, 17 June 2007 (UTC)

Never mind, I found exactly what I was looking for. After more research on this topic, I learned the proper keywords to search by, and came up with LTspice/SwitcherCAD III from Linear Technology, that can be acquired here. If anyone else is looking for the same thing, this is it. Thank you. — Kjammer  ⌂ 08:09, 17 June 2007 (UTC)

Just in case you want an alternative, yes EAGLE does do circuit diagrams, see the wikipage. However I've never actually seen a symbol for a junction box so I don't know about that. --antilivedT | C | G 08:38, 17 June 2007 (UTC)

[edit] Charset problem

I use "Spanish international" as my keyboard layout. Suddenly, I'm unable to type accents. Everything seems to work fine in the keyboard except the accent key, which won't work if I type "<accent key> <any letter>" but will work in "<accent key> <accent key>" or "<accent key> <bar space>". I can switch to Spanish traditional, but it's not the same keyboard mapping I have in my hardware and therefore it's a mess. Can this be a hardware problem? --Taraborn 10:11, 17 June 2007 (UTC)

First off, tell us what kind of operating system you are using. Otherwise we will not have the slightest idea how to answer this. --24.147.86.187 00:21, 18 June 2007 (UTC)
Sorry. I'm using Windows XP SP2, but the symptoms are way too unexplainable. Maybe this is due to some strange spyware. I'll have to format the HD. --Taraborn 15:03, 18 June 2007 (UTC)
It sounds like dead key typing got turned on. --Carnildo 00:17, 19 June 2007 (UTC)

[edit] ATX power exchange

(note: there is no more need to answer this question)

My computer is dead - when I push the power button nothing whatsoever happens. I want to test it with the power of another computer, but that is a different type of ATX. Then broken computer has two power connectors, one 20-pin and one 4-pin ('ATX12V 2.0' in the list in the article). The old computer has only a 20-pin connector (the first in the list). Can I safely plug in the 20-pin connector and ignore the other? Is there any danger to either computer (the new mb or the old power supply)? The mb manual says about the 4-pin connector: "If this ATX_12V connector is not connected, the system cannot boot." Sounds safe, but I don't want to cause more problems than I already have. DirkvdM 10:18, 17 June 2007 (UTC)

Never mind. Being a rather impatient character, I already tried it and nothing fried, but nothing happened either. I tried it the other way around and that did work, so the power supply isn't broken. Back to inspecting the mb. DirkvdM 18:46, 17 June 2007 (UTC)

You're sure the on-switch is plugged into the motherboard correctly? Who manufactured your motherboard? --Seans Potato Business 19:27, 17 June 2007 (UTC)
It's a Gigabyte GA K8NS Pro. When I connected the power to the other computer I also had to connect the power swith to it (the power signal goes through the motherboard) and that worked. So the switch isn't faulty. I have now completely disassembled, cleaned and reassembled the computer, but that didn't help. DirkvdM 06:29, 18 June 2007 (UTC)
You might try resetting the BIOS (e.g. by removing the CMOS battery and replacing it after 10 seconds). --Seans Potato Business 09:44, 19 June 2007 (UTC)
Good tip (should have thought of that myself), but alas, doesn't help. Btw, is it possible for the battery to run dry? The computer is only about two years old (maybe I should check what the EU warranty is on motherboards), so that's unlikely, but still, I wonder. DirkvdM 09:38, 20 June 2007 (UTC)
In my experience (and that garnered from asking other people myself (I used to be very scared of the CMOS battery running out!)) they last in the order of five years or so. You get absolutely nothing from the board whatsoever? Not so much as a flash of an LED or half turn of a CPU fan? I'd a) check there is no electrical short circuit, b) check that the processor and heatsink are appropriately seated and c) check if anyone has any ideas on a dedicated computer forum (including all information gathered so far so you don't go over old ground). And d) check that the CPU fan is plugged in to the motherboard. Someone on a forum might advise you as to where you could check the board for voltage with a multimeter, assuming that such an endevour wouldn't be dangerous. If all that doesn't work, maybe you could tell me what "wat 'n misser" means in English. Is that "'n" as in "een"? I'm rootin' for ya, even if no-one else cares! Also, do you know what may have caused the computer to go from booting up with its dodgy beep to not switching on at all (i.e. did you do anything to it between the last time you switched it on and the first time it wouldn't switch on)? --Seans Potato Business 00:47, 21 June 2007 (UTC)
I can not find a dedicated forum for this mobo, at least not on the gigabyte site (the internet connection is extremely slow on my old computer, so searching for much more takes extremely long). So I asked at forums.techguy.org, although that is also just a general computer forum, like this one. See if that leads to something. As for your language ref desk question, "'n" indeed means "een" and "wat 'n misser" means "what a failure/flop/poor shot", depending on the circumstances. DirkvdM 07:55, 21 June 2007 (UTC)

[edit] Wikipedia Random Article

Is it just me or is the Wikipedia random article button generates an article related to some articles that you've been looking at recently. articles related to the one I just looked at the same day have appeared in the random article link more than once. 141.153.150.122 16:44, 17 June 2007 (UTC)

I guess I can safely say its just you. Wikipedia keeps no records of pages you visit, AFAIK.--Seraphiel 16:55, 17 June 2007 (UTC)
Maybe your interests are too random. :) DirkvdM 16:56, 17 June 2007 (UTC)
Coincidence? Once I hit random article and ended up on the exact same page I came from O_O --frotht 20:33, 17 June 2007 (UTC)
I wonder what its way of choosing random articles is. I would not be too surprised if it did not actually choose a random article out of the million + available, but instead took it from some sort of recently-cached articles list or something. But who knows. The odds of getting the same article twice, assuming true randomness, is almost impossible ("one in a million"), which is what gives a good indication that it is not truly random in any way, shape, or form. --24.147.86.187 23:08, 17 June 2007 (UTC)
I think I saw User:Tim Starling say it took 1000 articles every few minutes and then chose a random one from it, then it generates a new 1000 articles again. x42bn6 Talk Mess 00:23, 18 June 2007 (UTC)
When it's first created, every Wikipedia page has a random number (between 0 and 1) generated and stored with it.
When you ask for a random article, a random number X is generated, and a query is done on the database along the lines of select * from page where page_random > X limit 1. (page is the table with one row for each article in Wikipedia.)
—Steve Summit (talk) 01:17, 18 June 2007 (UTC) [edited 04:56, 18 June 2007 (UTC)]
Wouldn't this specific query be biased depdning on the order in which the database processes its index, unless you include order by page_random to make sure you get the page with the lowest page_random above X? Even then, the distribution depends on the sizes of the gaps between the stored page_random values - they certainly won't all be of equal size. 84.239.133.38 06:19, 18 June 2007 (UTC)
I'm not sure about the ordering and the indexing. You're right about the gaps (as I explain below), but I doubt that factor is significant in practice. —Steve Summit (talk) 12:47, 18 June 2007 (UTC)
Our random pages aren't totally random. I believe that it only shows articles up to a certain size (they want them to be short so that people clicking them will expand them.) --(Review Me) R ParlateContribs@ (Let's Go Yankees!) 01:30, 18 June 2007 (UTC)
I don't believe that's true. As I understand it, the only nonrandomness is that if the random numbers associated with each article aren't evenly distributed through the interval (0, 1), some articles might come up more often. For example, if Wikipedia had only three articles, and their random numbers were 0.1, 0.7, and 0.8, the one with value 0.7 would come up more often, because during a Special:Random search, any value between 0.1 and 0.7 would hit that article. But with as many articles as Wikipedia has now, this effect should be completely negligible.
If the random article function seems to cough up small articles more often, that's simply because Wikipedia has so very many small articles. —Steve Summit (talk) 01:40, 18 June 2007 (UTC)
About two years ago, I read the complaint that the random articles were so often about small towns in the USA and the explanation given was that USians are so eager to write about their village, however small it is (and of course that it's such a big country and that internet penetration is fairly high). Maybe for this reason the function was changed from a random article to a random subject (and then a random article in that framework). Although that doesn't answer the question. DirkvdM 06:18, 18 June 2007 (UTC)
That happened because of User:Rambot, which created stub articles for every single town in the USA. At the time, it was a significant number of articles. --cesarb 09:46, 18 June 2007 (UTC)
I believe it was about one article in five. Today, the Rambot articles only constitute one article in 40. --Carnildo 00:20, 19 June 2007 (UTC)
Steve Summit's explanation is completely correct. To clarify, there is of course an ORDER BY page_random, which is fast because the column is indexed. The code can be viewed here, in selectRandomPageFromDB(). To all intents and purposes short of cryptographic analysis, for a project the size of the English Wikipedia, the page is randomly selected from among all pages. —Simetrical (talk • contribs) 01:34, 19 June 2007 (UTC)

[edit] Screen Rez in Ubuntu

I just installed Ubuntu. Using System:Preferences:Screen Resolution, the highest rez I can set is 1024 x 768, and the highest refresh rate is 60 Hz. However, I have an identical computer (same CPU, graphics card, & monitor) running Windows, that is set at 1600 x 1200 (and that's not the highest it will go) with an 85 Hz refresh rate. Any idea how to get the higher rez & rate on my Ubuntu box? --Tugbug 21:59, 17 June 2007 (UTC)

sudo dpkg-reconfigure xserver-xorg
-- Phoeba WrightOBJECTION! 22:01, 17 June 2007 (UTC)