Wikipedia:Reference desk/Archives/Computing/2007 May 3

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[edit] May 3

[edit] Fastest USB Flash Drive

What is the FASTEST USB flash drive? -68.193.147.179 00:12, 3 May 2007 (UTC)

This is the 3rd question you've asked about flash drives in the past few days. Perhaps you should visit USB Flash Drive and its sources to learn more about the biggest, fastest, strongest, smallest, etc. flash drives. Or better yet, try google: fastest USB flash drive. —Mitaphane ?|! 01:31, 3 May 2007 (UTC)


What will help you is by looking at the read/write speeds which are often marked on the manufactures web site

User:Nerdd 13:06, 3 May 2007 (UTC)


Memorex's M-Flyer is pretty fast

M-Fyer

    Read speed 25 MB per second and write speeds of up to 20 MB per second

200.35.168.129 16:48, 7 May 2007 (UTC) Ag for MemTech

[edit] Java

How can I create a Java application that runs when an icon is double-clicked; not from the command window? Also, why does my home computer not recognize the "javac" and "java" commands? Thanks, *Max* 01:20, 3 May 2007 (UTC)

As far as creating an application, you need to create a jar file. That article explains how to do it more or less.
As far as javac and java not working, you need to make sure that your classpath environmental variables are set correctly, as well as the running path environment variable. Generally speaking, in my experience, the frequent errors will be because you have not included the . directory in your classpath, as well as that the directories of javac and java are not in the running directory path (in Windows, that's the %PATH% environmental variable). –Pakman044 02:23, 3 May 2007 (UTC)
Sorry for stating the obvious, but make sure you have a Java compiler (e.g. Sun Java Development Kit or others) to compile Java; and a Java virtual machine (e.g. Sun Java Runtime Environment or others) to run Java programs. --Spoon! 04:04, 3 May 2007 (UTC)
Create a batch file. in that use javaw instead of java. you can avoid dos shell this way. also you can doble click on the icon to open the java application —The preceding unsigned comment was added by 61.246.232.126 (talk) 11:06, 3 May 2007 (UTC).
Also - there are development tools you can purchase that will take the java program and compile it into a Windows executable so it no longer requires Java to be installed on the computer. They work rather well, but the end result is always more bloated than an identical-functioning compiled C/C++ program. --Kainaw (talk) 15:14, 3 May 2007 (UTC)

[edit] is it possible to run code on the stack?

is it possible to run code on the stack? —The preceding unsigned comment was added by 165.228.95.126 (talk) 04:32, 3 May 2007 (UTC).

Yes and no. Without NX protection, then of course, that's how buffer overflows are exploited. With NX protection, this can't happen. —The preceding unsigned comment was added by 129.78.64.102 (talk) 04:49, 3 May 2007 (UTC).
(ec) Sometimes, yes. See NX bit for a discussion. --TotoBaggins 04:59, 3 May 2007 (UTC)
Depends on the processor architecture and how the memory protection is set. Most real computers (hardware+OS) never allowed execution from the stack as that's one of the main methods that malware uses to hijack the processor. Intel architecture PCs did allow this for a long time though, and it's still an option (for compatibility with poorly-designed programs that depend on that capability).
Atlant 12:49, 3 May 2007 (UTC)
Trampolines are implemented using an executable stack. --TotoBaggins 15:40, 3 May 2007 (UTC)

[edit] Multilayer Circuit Diagrams

Hello. What's the process used to create multilayer circuit diagrams that make up the microchips in computers? Thanks. --Mayfare 04:37, 3 May 2007 (UTC)

If you're asking how the wires are allocated to the various metalization layers and routed, it's done by software that processes for a very long time to achieve a near-optimal layout. Prior to that, floorplanning software placed the various functional units of the chip so that the wiring problems would be minimized. It's essentially the same problem faced by printed circuit board layout software, but in miniature.
Atlant 12:53, 3 May 2007 (UTC)

[edit] Unicorns

Does anyone know any facts, percentages, know-how or other miscellanous knowledge on how to aquire the unicron in elder scrolls: oblivion. (i am assuming it is the same on all platforms but i have a ps3, just in case it affects anything)

Thank You --89.241.1.180 09:01, 3 May 2007 (UTC)

Check out www.gamefaqs.com - one of the top free sites for that sort of thing. Do a search for the game, then look at FAQs or Codes (you'll find what you're after in one of the FAQs/Walkthoughs) Rfwoolf 12:12, 3 May 2007 (UTC)

[edit] The Internet

If the internet was converted into 1sq mile for every 500mb of data on it, how big would it be?

Thanks

--89.241.1.180 09:02, 3 May 2007 (UTC)

http://www2.sims.berkeley.edu/research/projects/how-much-info-2003/internet.htm according to this, 1,117,566,009 Miles squared. For reference, earth is about 316,940,070 square miles of surface area, including water surface area., or 1/3rd the size. I think a square mile could hold more than 500MB though. 500MB sounds about the same as a movie, although I haven't downloaded any in a looong time, but I have to imagine a film reel is nowhere near a square mile in width*length dimensions -- Phoeba WrightOBJECTION! 10:02, 3 May 2007 (UTC)

500MB is quite small for a square mile, I think. If we encoded the (2003) internet by black and white squares on paper, and made each square one millimetre across (say), then each square mile would encode about 300GB, so the internet would take about 1.8 million square miles, or about the are of the european union plus norway. Algebraist 12:34, 3 May 2007 (UTC)
Okay, how big would the internet be if you wrote it out in binary in size 10 arial? I'll work this out when I get home if nobody else has (I guess we can assume 50/50 distribution of 1/0s. - since arial isnt fixed width. --213.48.15.234 14:57, 3 May 2007 (UTC)
The proportion of 1s and 0s is irrelevant - assuming you're viewing this in Arial, these two lines should be the same width:
00000000
11111111
To answer your question, I calculate it to be around 865,155,330,000,000 (865 trillion) sheets of A4 paper. Using the default OpenOffice.org settings, I can fit 5418 bits on a page in 10pt Arial. — Matt Eason (Talk • Contribs) 15:39, 3 May 2007 (UTC)
The internet is not a data storage device, it is a data transfer network, so it doesn't really make sense to talk about the size of the internet in terms of storage. It would be more meaningful to talk about data transfered over time. I also don't think that converting this value arbitrarily into spatial dimensions like area renders any useful comparisons. -- Diletante 15:31, 3 May 2007 (UTC)
A good point. I remember reading at one point that the bandwidth of the entire internet was less than a hatchback full of 8 tracks travelling down the highway, however that was very much over a decade ago, so you can consider it fiction now. -- Phoeba WrightOBJECTION! 17:55, 3 May 2007 (UTC)
I can fit 2,849 characters on a page in size 10 Arial, single-spaced, alternating 0 and 1. --TotoBaggins 15:35, 3 May 2007 (UTC)
I think that depends on your margins, I have a full a4 page of 1s and 0s with no margins, all the way to the edges and I have 6360 bits. Vespine 00:48, 4 May 2007 (UTC)
Awesome, I completely forgot about this by the time i got home :D 213.48.15.234 06:50, 4 May 2007 (UTC)

[edit] Opensource Java Barcode Image Reader

Is there an opensource barcode image reader in Java? I want to give an api a jpg or gif from another java app and get the barcode number from it. I have seen the Tasman.bars thing but it is too expensive, i need something free. --68.154.107.171 15:04, 3 May 2007 (UTC)


Why not just decode the barcode in word with a free converter ..and then just copy and past the number ! It would be helpful to know the application for which you plan to use this for.--Nerdd 20:55, 3 May 2007 (UTC)

The answer appears to be "no". An alternative would be to use a non-Java open-source OCR package that handles barcodes, and write a Java interface to it with JNI or whatever. --TotoBaggins 15:04, 4 May 2007 (UTC)

[edit] Username changing over the Internet

A group of friends and I don't understand why most companies don't allow you to change your username on their sites. It makes sense, but we don't understand why.

--Ian 17:36, 3 May 2007 (UTC)

Two reasons:
  1. Changing username will require the site to update your username everywhere it is recorded.
  2. Changing a username will cause any place it isn't updated to show the wrong username.
So, it is a database issue (in the first case) and a responsibility issue (in the second case). The database issue is just a programming issue. The responsibility one is now. For example, what I wrote about how much Wikipedia sucks and then changed my username so I wouldn't have to accept responsibility for the statements made by me previous username? --Kainaw (talk) 17:41, 3 May 2007 (UTC)
Well if your username changed everywhere, we would see the new username as the author of the troll comment, right? I think the answer is simply that even though it's not awfully difficult to include this feature, it's even easier not to include it. —Bromskloss 20:42, 3 May 2007 (UTC)
It's certainly not due to technical restrictions - any good database will have a separate unique field such as a user id number that's transparent on the frontend. But it's confusing for users if peoples names change often, especially in community-based apps like forums or wikipedias. --frotht 02:04, 4 May 2007 (UTC)
It is true that a database will likely use a key other than the username, but, if I were to say that Ianweller asked this question and both Bromskloss and Froth answered it... how would a database key know to look through this comment and update those names? That is what I was referring to by having the old username present and difficult to change. --Kainaw (talk) 02:12, 4 May 2007 (UTC)
As most readers of TheDailyWTF will know, a lot of databases are not good databases... --cesarb 17:03, 6 May 2007 (UTC)

[edit] Backwards in GarageBand

Is it possible to play things in reverse in GarageBand? —The preceding unsigned comment was added by 71.34.38.123 (talk) 20:18, 3 May 2007 (UTC).


Have you tried Apple Garageband support? also this Apple Forum might be what your talking about.--Nerdd 21:04, 3 May 2007 (UTC)
No, i'm looking for how to make sections (primarily vocals) backwards so when i play it that section is reversed. —The preceding unsigned comment was added by 71.34.38.123 (talk) 21:40, 3 May 2007 (UTC).
You could import the vocal (assuming its in WAV or the like) into Audacity, reverse it there, and reimport into GarageBand. -- Finlay McWalter | Talk 00:31, 4 May 2007 (UTC)