Wikipedia:Reference desk/Archives/Computing/2006 December 1

From Wikipedia, the free encyclopedia

You have new messages (last change).
Computing desk
< November 30 << Nov | December | Jan >> December 2 >
Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


Contents


[edit] December 1

[edit] reseting admin password in xp

i need to reset the admin password on a computer, i have full accesss to it (cd, floppy, usb) but cant log in, does anybody know of any way to reset the admin password? preferably a downloadable iso or something thats freeware, thanks a lot --69.140.210.163 01:24, 1 December 2006 (UTC)

This may not be legal due to DMCA restrictions on circumventing protection technology, but info can be found here. Use at your own risk! Droud 01:35, 1 December 2006 (UTC)
That looks pretty dubious to me. They basically require you to send them information from your computer and then they will give you the password. Sounds a little sketchy. --24.147.86.187 02:03, 1 December 2006 (UTC)
On second thought, DMCA has nothing to do with it as long as it is your computer. These methods are NOT failproof and will typically result in you losing any and all private files on your computer. Use at your own risk! Droud 01:40, 1 December 2006 (UTC)
I've used this utility in the past with good effect. However if the user files are encrypted you will be out of luck even if you reset the password. But if you do all of the disk-image stuff there it should be able to reset the admin password to whatever you want. --24.147.86.187 01:59, 1 December 2006 (UTC)

download the ophcrack livecd, pop in in and turn on your computer. Wait 25 minutes or so and it'll crack the password. Windows passwords pfft :) --frothT C 02:48, 1 December 2006 (UTC)

I've used the one User:24.147.86.187 linked myself successfully. --Wirbelwindヴィルヴェルヴィント (talk) 16:46, 1 December 2006 (UTC)

wikibooks:How to Crack Windows XP Passwords WP 07:45, 7 December 2006 (UTC)

[edit] How to connect a doorbell to a laptop

I would like to write a "chess clock" for a game with more than 2 players. Because not everyone can reach the computer easily, I want to connect the computer with a number of doorbells, and place one in front of each player. Is this possible with USB? Maybe there's already an adapter for this? How do I adress it from the computer? (I've done something similar with a serial port, but that was many, many years ago.) — Sebastian (talk) 02:13, 1 December 2006 (UTC)

It might be difficult to get it down to the right voltage so you don't fry the port.. --frothT C 02:50, 1 December 2006 (UTC)

Could you hack apart a USB keyboard and just use the space key or something? Fit it into a small switch box. That's the way I'd try to do it, I'm sure you can get some creappy keyboards for a couple of bucks if you don't already have some kicking around.. Vespine 03:27, 1 December 2006 (UTC)

Thanks for both your tips. The idea with the keyboard feels like overkill and much more work - I would need 6 of them. But it is an interesting backup solution. Ideally, all I need is a simple (passive) switch - nothing that provides its own voltage. It doesn't feel so exotic to me, but apparently nobody does this sort of thing with a laptop. — Sebastian (talk) 05:32, 1 December 2006 (UTC)

It would 100% be simpler to use the parallel port on your computer to do this. If you used USB you would likely have to create drivers for it? Not too sure.
Head to your local electronics store, grab a male parallel port and then get some parallel ribbon cable that has no ports on it, then you will need to put the port and cable together which is brutally easy.
I recommend parallel because it is easy to see and count the wires that you are using and makes troubleshooting easier.
To make things connect i'd use a breadboard which will allow you to just stick the wires in.
The doorbells will close the circuit from the parallel port, talk to the guy at the store and see if he knows if you need any resistors and or external power. This is where the breadboard would come in handy. If you don't need external power or resistors then you don't need a breadboard.
Then you will have to write a program to a signal through say pin 1? (not sure if this is reserved or not) and wait for a signal on pin 2. when you push the door bell the signal from pin 1 would be routed back to pin 2 signaling an event.
A simple way to program this is in MSBasic, but i know you can use Visual basic, it will just be a tad harder but you should be able to do more in the end.
Sorry my help is so vague, I did a similar project 4 years ago and I can't remember details. --Sish 05:58, 1 December 2006 (UTC)
Thank you! This isn't vague - it was very helpful. It led me on the right track: I just searched for "USB to Parallel", and there seem to be several products that I could use. Thanks a lot! — Sebastian (talk) 06:09, 1 December 2006 (UTC)
On second thought: How do these adapters actually map the many parallel contacts to the 4 USB pins? I guess I have to do a bit more resarch. — Sebastian (talk) 06:13, 1 December 2006 (UTC)
OK, I think I'll buy a DAQ device. I always wanted one, anyway, and one for about $100 should do for me. — Sebastian (talk) 06:27, 1 December 2006 (UTC)
Depends what kind of computer you're using :-) The easiest possible way i can think of would be if you had an Amiga / ST / Sinclair Spectrum as you could use the inbuilt (digital) joystick port - virtually all programming languages for these architectures have commands to read specific input pins. If this ain't the case, you could also use the non-data lines in Serial Port, such as CTS, DTR - [1] may be useful for this. On the subject of how a USB/Parallel converter maps the pins from one to another, it doesn't. It provides an interface from one interface standard to another (in the same way as your internal parallel port wil have an interface to the PC on one side (probably PCI) and to your parallel deveice on the other. Davidprior 06:45, 1 December 2006 (UTC)
Thank you! Unfortunately, it's a Sony!. It doesn't have any parallel or serial port. But don't worry, I think the DAQ device will solve the problem. Not the cheapest solution, but I can use it for other things, as well, and it'll remind me of my days in a physics lab, so it'll be worth it. — Sebastian (talk) 07:21, 1 December 2006 (UTC)
Vespine's keyboard idea seems like by far the easiest solution, and you really only need one keyboard. You just buy a cheap keyboard (£5 max), dismantle it and chuck away the key mechanisms. Then solder six pairs of bellwire to (any old) six contact pairs on the circuit board underneath, and have the bellpushes on the ends of those wires. This really seems the smartest idea, because:
  • the cost is negligible, and if you screw up you can always solder on different contact pairs (or get a new keyboard for next to nothing)
  • there's essentially no programming overhead - keyboard IO is the easiest of all in pretty much every OS/environment/language
  • the hardware part is very easy (the largest solder targets ever) and fast (maybe 30 mins work)
If you have to worry about simultaneous keystrikes (as you would if you were making a quiz-show buzzer-system) then you have to be careful about wiring keys that are disjoint in the keyboard matrix. -- Finlay McWalter | Talk 00:24, 2 December 2006 (UTC)
But of course! You're right! It didn't occur to me that I don't need the keys mechanisms themselves. I'll try that. — Sebastian (talk) 00:36, 2 December 2006 (UTC)

[edit] Playstation2

I've got a Sony Playstation 2 (non-slimline) and the disk drive on it no longer opens. This was caused by the unit being stored upside-down once. Is there any way this can be fixed? Mix Lord 04:37, 1 December 2006 (UTC)

All you have to do is unscrew your PS2 and find if anything is jammed, snapped or fried. Here is a guide. meltBanana 16:12, 1 December 2006 (UTC)
that happened to me once, but i fixed it. all i did was soak it in warmish water for 3 to 4 hours and it should be as good as newSir Sagman 04:56, 3 December 2006 (UTC)
If those solutions don't work, you can always call Sony and purchase a refurbished "fat" model for a discount if you send in your broken out-of-warranty model. (As I have done) Jmax- 03:11, 7 December 2006 (UTC)
i wouldn't suggest soaking your PS2 in water, and would much less suggest taking it apart, unless it really is out of warranty, in which case, i'd do as Jmax hear tells you.in case of no money, do as Mr. banna tells ya to. Xiaden 22:34, 7 December 2006 (UTC)

[edit] Pci speed

How can a PCI card providing usb 2.0 ports offer full 480 mpbs?or does it??

According to Peripheral Component Interconnect PCI supports up to 133 MegaBYTES per second.
133 megabytes = 1 064 megabits
1064 mbps/480 mpbs = 2.21
So technically one could have two whole devices running at 480mbps on a PCI USB 2.0 Card --Sish 07:10, 1 December 2006 (UTC)

[edit] Open source Linux OS

Any idea which is the 1)fastest 2)most multimedia compatable(file formats) 3)smallest size 4)applications(open office,etc) among all the linux os??

Linux OS? never heard of it. I thought Linux was a kernel... unless you're looking for GNU/Linux [sarcastic] --wj32 talk | contribs 00:46, 2 December 2006 (UTC)

What do you mean by smallest? Feather Linux is only 120 MB or so, but Ubuntu is more full-featured and is what I would recommend for you. It is freely available here -- it's only around 700 MB and includes OpenOffice. You may need to install some codecs or applications to deal with Windows Media files (WMA, WMV) and CSS-scrambled DVDs. Pesapluvo 15:57, 2 December 2006 (UTC)

[edit] Determining the character set of a file (created by cURLing wikipedia)

Alright, so there are two ways to solve the problem I have.

1) Tell me the character set of the file "foo" given that foo was created by the command

cURL -dump http://en.wikipedia.org/w/index.php?title=dali&action=raw > foo

(except with the ? and & escaped so it works - the version presented above is unescaped for ease of your link following).

2) Tell me in general how to determine the character set of a file. Bonus points if it doesn't involve installing a utility (the system already has "recode", but it doesn't seem to do character set recognition, just recoding).

If you need or want more information on the context, read on.

That particular sample page is useful because it uses an 'í'. I have no problem seeing the í using for instance cat. The difficulty is that I want to process the file in Java, in particular using a Scanner. I've written a testing utility in Java that basically replicates the functionality of cat, just reading a file in and putting it directly to standard out. However, the Scanner constructor takes an argument of the character set used, and I don't know what to put. I've tried all the most common options (UTF-8, UTF-16, US-ASCII, ISO-whatever): the good ones tell me about "Salvador Dal?" while others don't even parse into words correctly.

I wouldn't mind a few missing characters, but when instead of dali I'm looking at http://ar.wikipedia.org/wiki/%D9%85%D8%B3%D9%8A%D8%AD%D9%8A%D8%A9, it becomes very problematic. Incidentally, I assume that dali and the above link to the Arabic Wikipedia use the same encoding - if not, please explain how and where Wikipedia uses various different encodings. LWizard @ 11:08, 1 December 2006 (UTC)

When grabbing an HTML file (as you will with that ar link), the HTML often has a meta tag labelled "Content-Type" which mentions a character set. Otherwise, you probably need to grab the header of that name out of the HTTP conversation; I don't know if cURL can report that or not. In general, of course, there is no way to tell what character set an arbitrary file uses, because you don't know what the file is supposed to say. (You can often tell that a file is encoded with such things as UTF-8, but that's not a coded character set (though those two links point to the same place, read the "Modern encoding model" section there); I guess the Scannner constructor is using the term in the old MIME sense. Are you sure that the UTF-8 there is not Java's modified UTF-8? Fortunately, most uses of variable-length encodings like that use Unicode as the character set. As far as my limited knowledge of internationalization goes, it appears that that's what your cURL command retrieves.) --Tardis 16:08, 1 December 2006 (UTC)

[edit] install windows 98

I have windows 98 in drive c: and xp(service pack 1) in drive d: (windows 98 to use mediaforte PV-951 TV card. XP does not support the tv card. Hence I need windows98). Now I could not run 98. When I boot 98, it says “Error starting program The shell32.DLL file cannot start. Check the file to determine the problem.” Another dialogue box says “Explorer This program has performed an illegal operation and will be shut down. Explorer caused an exception 6d007eH in module EXPLORER>EXE at 0167:0040a067” How can I solve this problem?

I tried to format drive c: to reinstall win 98. but I could not. It says “windows was unable to complete the format.” Why I could not format drive c? is it due some common files shared by 98 and XP? Can I format drive c after manually delete all the files in drive c:? I could not find update drivers for mediaforte PV-951 TV card in the web. Can you help? Can I reinstall 98 while Xp is already installed in drive d? What are precautions I have to take before formatting (FAT32)? Sorry for the troubles. Thank you very much for your help. 220.247.226.158 11:09, 1 December 2006 (UTC)

[edit] software

Hi,

I need a software where i can store large amounts of data on.

If i was to type a trace number or an id number in, then all the information for that particular trace number will come up.

The information is for certs for our products. And the trace numbers are our references in completing the certifications.

Please can anyone help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

<email removed>

Maybe you're looking for a database? --Wirbelwindヴィルヴェルヴィント (talk) 16:44, 1 December 2006 (UTC)

[edit] testing my own wlan

I want to know if my wlan is secure. Do you know any hacking software so I can test it?

The guidelines in Wi-Fi_Protected_Access#Security_in_pre-shared_key_mode are quite good. If you follow these, you should generally have no issues with security. If, however, you are determined to test your security, then take a look at AirSnort or Aircrack-ng Jmax- 03:17, 7 December 2006 (UTC)

[edit] Program in USB

If I install a program in a USB stick, can I use this program on any other computer (with the same OS)? Or will the installation of some files still put some information on my hard-disc?

It depends on the program. If it doesn't change registry values and install files in system folders, you can. For example, Mirc (the irc client) can run from a USB drive. --Wirbelwindヴィルヴェルヴィント (talk) 16:42, 1 December 2006 (UTC)
I was thinking about something more professional, like ms-office, my own web-browser, a CAD program, etc.
MS Office requires registry and many libraries. So, the executable file is rather useless on its own. Most modern Windows programs work like that. You need to have all the libraries and registry settings installed to get it to even think about running. --Kainaw (talk) 18:01, 1 December 2006 (UTC)
But, what if I configure the usb stick as the main storing devide, and install windows on it (hypothetically). Would I be able to use this usb stick on any computer?
Only in safe-mode. When you install windows, you install drivers for the computer it is on. Also, Windows (and Vista) validate themselves based on the CPU and other things in the computer. So, when you switch hardware, you'll have a hell of time getting the different video card, network card, etc... to work properly. --Kainaw (talk) 20:19, 1 December 2006 (UTC)


[edit] Another problem with javascript

Yhea... i would like to pass a javascript variable from a main body to an iframe. how would i do that? it doesn't seem to work at all... here are the declarations i used:
in the body - var name="Home";
In the Iframe- document.write("-" + name + "-");
Is it Steak?<Xiaden's Homepage> 15:20, 1 December 2006 (UTC)

Are both pages (the main one and the one in the IFrame) on the same server? If not, you will not be able to do it because of security protection. --Kainaw (talk) 18:00, 1 December 2006 (UTC)
Actually, they aren't even online yet, but they are in the same folder, and will be uploaded accordinglly. i like having things work before i try and upload anything =p. but on a serious note, i really need this information quick... it's part of a deadline(three days from now). Thnks,
Is it Steak?<Xiaden's Homepage> 18:57, 1 December 2006 (UTC)
Then, the iframe should be in the window.frames array. If it is the only iframe, I'd expect it to be window.frames[0]. You can use windows.frames[0].document.write... but keep in mind that this all changes based on exactly how you coded the web pages. It may be parent.frames or windows.frames[whatever_you_named_the_frame]... Firefox (Mozilla) is nice in that you have a DOM inspector that you can use to see exactly where every element on the page is at and what you need to reference it. --Kainaw (talk) 19:05, 1 December 2006 (UTC) <--- this is an example of a good anwer.
Ha... you helped me, but not in the way you exspected... turns out, whatever i name the IFrame, turns into the name for the variable name... i used a variable that isn't supposed to be used... i can define it in the tag now though, so it's all cool. Tell me if you want me to explain more...
Is it Steak?<Xiaden's Homepage> 19:11, 1 December 2006 (UTC)

Thanks for the help, it's running fine, but i'm curious as to why it allows the tag to change a javascript variable. I'ts a trivial matter, but all the same, could someone answer it? 168.169.107.2 14:44, 4 December 2006 (UTC)aka[[user:XiadenXiade]]n 18:35, 5 December 2006 (UTC)

Bumping this question, so someone will see it(hopefully)[[user:XiadenXiade]]n 18:35, 5 December 2006 (UTC)

[edit] rdesktop resize

I've been looking through the man file and I can't figure out if this is possible. With rdesktop (from linux to windows), I would like to be able to resize the window and have Windows change the resolution on the fly. Is that possible? I know I can close rdesktop and open it with a new geometry - which is not what I want. --Kainaw (talk) 18:02, 1 December 2006 (UTC)

Changing the desktop resolution on the remote windows system will change the rdesktop window size. My searching did not turn up any implementation of the reverse, but the protocols seem to support it. There are already feature requests for this. Droud 23:42, 1 December 2006 (UTC)

[edit] making money

Does anyone know any easy and efficient ways of making £500 online quickly. any help would be appreciated. cheers ams

Make a website and sell (insert any item that is popular in spam these days here). You don't have to actually ship anything. You don't even need to accept credit cards. Send out spam to get people to visit your site. When the idiots flock in to give you their credit card info, copy it all to a file and sell the credit card information to some criminal for whatever he'll pay. Make a new site. Send out more spam. Do it again. By the time you get caught, you'll have made enough money to afford a high-priced lawyer and get, at most, probation and a small fine. --Kainaw (talk) 19:08, 1 December 2006 (UTC)
dear god, i hope your joking Is it Steak?<Xiaden's Homepage> 19:12, 1 December 2006 (UTC)
Is the sense of wikipedia to provide criminal advice, to, err..., may I say potential criminals?Mr.K. 19:15, 1 December 2006 (UTC)
Yes, especially when you blatantly lie to them and tell them they won't be punished much when they are caught. One more idiot behind bars is good. --Kainaw (talk) 19:27, 1 December 2006 (UTC)
And, why make a web site? Couldn't you just cheat people through ebay like many others have done before?Mr.K. 19:32, 1 December 2006 (UTC)
Too difficult to get volume. With spam, you can get thousands of valid credit card numbers in a matter of hours. I know that it is hard to believe, but many people actually click on those links and type in their credit card information. And they say that humans have evolved past the law of survival of the fittest... --Kainaw (talk) 19:36, 1 December 2006 (UTC)

[edit] how much bits does a chip have?

I know the whole story of words of 32 and 64 bits, but how much bits does a microchip has in total?

There is no set amount. It depends entirely on the chip. Some have more. Some have less. --Kainaw (talk) 20:17, 1 December 2006 (UTC)
Er, wrong answer. Words are memory, not processing. You might be thinking of transistors. CPUs have hundreds of millions of transistors. --frothT C 21:30, 1 December 2006 (UTC)
Microchips come in many flavors, and the "bits" a certain chip has refers to either:
  • The numerical precision of the processor and its registers. This is how commercial CPUs are measured in 8, 16, 32 and 64 bits.
  • The bus width the chip uses to access memory. This is how consumer gaming products were measured in 64 and 128 bits.
It is rare for a modern chip to have a numerical precision that differs from its bus width. Droud 23:49, 1 December 2006 (UTC)
Maybe you mean how many total bits a processor has in its registers? That varies by chip as well; x86 chips are known for having few, and MIPS chips for having many. Of course, there are also the issues of CPU cache size... --Tardis 23:52, 1 December 2006 (UTC)
eax, ebx, ecx, edx, edi, esi, eip, esp, ebp, floating-point registers... ... ... ... --wj32 talk | contribs 00:43, 2 December 2006 (UTC)
To The Person who asked the question: you would get a sensible answer if you told us the context of what you are asking about, because bits in information/computing are not "things" that you can see (like bits of an engine or so), but rather a measure of the size of information groups that travel through the processor. So a chip does not "have bits". Click on Bit for more info. -- Seejyb 05:26, 2 December 2006 (UTC)

Memory chips come in sizes up to about 8 GB [2], which, at 8 bits per byte, would be around 64 billion bits. StuRat 09:24, 2 December 2006 (UTC)

This is an intriguing, unansweable question. Theavatar3 18:06, 5 December 2006 (UTC)

[edit] Forums/Places to ask computer questions

I'm looking for other places to ask computer questions (and see answers, and perhaps contribute some of my own) or computer discussion forums. Can anyone recommend any good ones? I'm interested in sites for the following topics: programming, theoretical computer science, interesting software/website/technology, employment/business ideas. Robin

There are a number of technology related forums such as Ars Technica and Topix Science/Technology, and Topix has a Computer Science forum as well. Your best bet for programming forums would be choosing a language first. As far as employment, head over to Monster. Droud 23:57, 1 December 2006 (UTC)

[edit] Internet

How many trans-Atlantic internet links are there, and what type? Auximines 23:00, 1 December 2006 (UTC)

I don't have a number, but look to List of international submarine communications cables and this category for help. - (Nuggetboy) (talk) (contribs) 00:14, 2 December 2006 (UTC)
OK, try Category:Submarine communications cables in the Atlantic Ocean too. It's growing as I'm trying to sort them out myself. - (Nuggetboy) (talk) (contribs) 00:35, 2 December 2006 (UTC)
Thanks very much! So, does all traffic go by submarine cable rather than by satellite? Auximines 17:32, 2 December 2006 (UTC)
I can't say for sure, although I did see in one of the articles or references that the submarine cables are much preferred to satellite and the demand for satellite is vastly reduced when cable bandwidth is available. I would say there will always be demand for satellite communications, but probably only to remote areas where cables are unavailable or impossible. - (Nuggetboy) (talk) (contribs) 22:25, 2 December 2006 (UTC)
Here in South Africa, our sole telecomms operator Telkom monopolized the trans-atlantic link to At&T, so rival ISP's who were big enough, notably The Internet Solution, made sole use of satellite bandwidth. When their "lines" are down they have the added advantage of blaming weather and interference from sunspots etc. :) We are in an awkward geographic location so all ISP's charge exorbitant rates, but we all know it's nothing other than corporate greed and don't-care politicians who have vested interests. Sandman30s 11:58, 4 December 2006 (UTC)

[edit] That's Bots' Work!

I was just wondering whether it's really necessary to check for and correct double-redirects if there are bots that do that anyway - how long is a double-redirect likely to be around before a bot fixes it? --Username132 (talk) 23:46, 1 December 2006 (UTC)

Where does it say it's necessary? You might want to change that. All I'm aware of is the statement " A double redirect does not work" in Help:Redirect; if you're sure that the bots do their job sufficiently you may want to add that there. — Sebastian (talk) 03:38, 2 December 2006 (UTC)
When I moved a page, I was told to check for and fix double redirects that the move may have created. --Username132 (talk) 10:59, 2 December 2006 (UTC)

[edit] Want to download wikipedia

Hi is it possible to download a "database" of wikipedia, for use in a handheld device?(palm pilot) so that i can look anything that was included at that time when i am offline.. Thank you. Daniel.

You can download a dump of the Wikipedia database, but you'll have to code your own XML to text file converter. --wj32 talk | contribs 00:41, 2 December 2006 (UTC)
There is one already made http://download.wikimedia.org/tomeraider/ if you have tomeraider. meltBanana 15:36, 2 December 2006 (UTC)
If you're talking about the entire database, then that would likely be impossible - it is many terabytes in size. RevenDS 15:45, 3 December 2006 (UTC)
Retrieved from "http://en.wikipedia.org../../../r/e/f/Wikipedia%7EReference_desk_Archives_Computing_2006_December_1_bbef.html"