Wikipedia:Reference desk/Archives/Computing/2008 April 20

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[edit] April 20

[edit] Don't Think that Digital Data will Last Forever

It's pretty frustrating and disappointing after I read this article Coming Soon: A Digital Dark Age?. (see also Digital Dark Age) I thought digital way is the best and perfect way to preserve data. However, it turns out I was wrong. Hardware and software are evolving so quickly such that they are not compatible to each other in terms of time. It seems open-source software is a solution on the software side. But there seems to be no virtual machine can emulate all kinds of out-of-date hardware. All digitals are gone after 17 years according to the article. - Justin545 (talk) 00:28, 20 April 2008 (UTC)

Please see XML and consider that the last iterations of digital media have been the Compact Disc then the DVD and now the Blu-Ray. Even predecessor media - Floppy disc - had a magnetic circular disc media. While it's true a similar leap in fundamental media is not only possible, but suggested by current technological trends (Solid-state drive and Quantum computing among others ). Ultimately, you should turn to the example set by Ozymandius. (Post script - if one of the regulars would be so kind as to truncate my links, I would appreciate the edit) (Post post script - thank you, Astronaut) Ironmandius (talk) 00:30, 23 April 2008 (UTC)
Wikified links as requested. Astronaut (talk) 03:26, 20 April 2008 (UTC)
Do you, um, have a question? In any case, 17 years sounds unlikely to me, personally, and I don't think things are going to be quite as dire. The historical examples they bring up are not so much about different hardware as they are about different consumer models—yes, the hardware changed a LOT in the last 20 years, but more importantly the people who were USING the hardware changed a lot. NASA can't get its old data but that's not really because the machine is out of date, it's because it was on a machine that even at the time a relatively small subset of people knew how to use and operate, so there's a lot less existing infrastructure in place to recover that knowledge, and nobody has been ushering it along to new machines, new formats, etc. as standards changed. As computers have penetrated all aspects of individual life (for those in the West, in particular), though, the incentive for keeping it easy to read legacy formats goes up exponentially as well. Standards change and evolve, but if the incentive is there it is easy to convert formats or maintain legacy issue. It's very telling, as well, that virtual machines can emulate pretty much any out-of-date hardware that had real commercial viability at one point. No, we can't emulate the Harvard Mark I, but we can do Commodore 64 without a hitch. The sheer number of computers produced today insures that it probably won't be too hard to emulate (if not actually run) old hardware in the future. --Captain Ref Desk (talk) 02:58, 20 April 2008 (UTC)

Better, freely accessible, and more thorough documentation for file formats will probably go a long way in avoiding situations like this. By the way, don't we already have file formats like PDF/A for archival? Moreover, as Neal Stephenson discovered in In the Beginning...was the Command Line,

I could have chosen the "save as text" option in Word and saved all of my documents as simple telegrams, and this problem would not have arisen. Instead I had allowed myself to be seduced by all of those flashy formatting options that hadn't even existed until GUIs had come along to make them practicable. [1]

Requiring patent applicants to fully document everything (in such a way that the day the patent expired, someone could build the "invention" with just the documentation) that they have "invented" before a patent can be issued could also be a good stop-gap measure. Kushal 14:35, 20 April 2008 (UTC)

Except that, on the other hand, having strong patent control over formats can prohibit their being used in the first place. I still think that ubiquity will matter more than legibility when it comes to formats; no matter how complicated it is, if people need to use it/update it/convert it, there will be a way to do it. If patent control over formats keeps them from being used widely, then there'll be no reason to rejoice when the patent expires 14 years down the line. --Captain Ref Desk (talk) 18:34, 20 April 2008 (UTC)
Just a wry comment in passing: History seems to be proving that the best method of preserving data is to inscribe it on clay tablets, bake them and bury them in a dry place. The next best method is to carve it into the wall of a cave. How much of our data will last the ten thousand years that Mesopotamian cultures have achieved for theirs? Retarius | Talk 05:16, 21 April 2008 (UTC)
I'm not so sure that is a good comparison. In 10,000 years, I believe some of carvings on our buildings and statues will still exist just like similar Mesopotamian carvings. Woodcuts, paper and some types of art work (paintings and sculpture) will also probably survive 10,000 years if stored properly. Digital data however is vunerable to magnetic or UV damage or, if forgotten about, the ever changing digital format changes leaving the media without a device to read it with. Astronaut (talk) 09:30, 21 April 2008 (UTC)
Project Gutenberg uses non-fancy vanilla text. Will our using vanilla text help preserve it over the long term? Kushal 11:48, 21 April 2008 (UTC)
If you print it on paper suitable for long term archival and use a suitable ink, and store that paper under ideal conditions, it doesn't matter which font is used. If it is kept in digital format and requires a fancy font, any font definition files might be unusable. But also consider what might happen in a thouand years when everything is perhaps double-byte characters and single-byte characters can no longer be read by the software of the day - your ancient document could be rendered as gibberish. Astronaut (talk) 12:48, 21 April 2008 (UTC)
Yes, a plain text file certainly is likely to last longer. I'd particularly avoid using any proprietary format, as it may not only no longer be supported by the company that holds the patent, but they may prevent third parties from offering software to read it. StuRat (talk) 16:16, 21 April 2008 (UTC)
Agree. I think proprietary formats/standards can't be trusted. The users of which could be suffer from paying money for upgrading their software to access the lastest format. Since the older formats are no longer supported. The companies 'may' actually change the formats ON PURPOSE to earn more money from their users. - Justin545 (talk) 01:34, 22 April 2008 (UTC)
ASCII text has managed 40 years so far, and since UTF-8 is a strict superset of ASCII, I see no reason to believe it won't be readable in the future. --Carnildo (talk) 21:34, 21 April 2008 (UTC)

[edit] C# Syntax

I've been trying to learn some C# and came across this puzzling bit of syntax:

 System.IO.DirectoryInfo dir=new System.IO.DirectoryInfo(@"C:\");
 foreach (System.IO.FileInfo file in dir.GetFiles("*.*"))
 {
 ...

What is the purpose of the "@" before the string, and why is it not needed in the next line? Astronaut (talk) 02:39, 20 April 2008 (UTC)

Google gave me an answer: What does an @ before the start of a string literal mean? — Kieff | Talk 05:48, 20 April 2008 (UTC)
Thanks. I seached MSDN for a good half hour for an answer and didn't find that. Astronaut (talk) 17:55, 20 April 2008 (UTC)

[edit] Visual Studio 2008 Express

Can I use a version control system (preferably a free one such as CVS) with Visual Studio 2008 Express? If so, how is it integrated with the Visual Studio IDE? Astronaut (talk) 02:46, 20 April 2008 (UTC)

[edit] Mozilla Thunderbird -- Top-Quoting Possible?

Hello,

I would like to know if there is a way to force Thunderbird to top-quote when replying to emails. I understand that it's not the best email form, but my work place requires it.

Thank you for any help,

--Grey1618 (talk) 10:19, 20 April 2008 (UTC)

go to Account Settings for your account -> Composition & Addressing -> Composition -> Automatically quote the original message when replying -> then select "start my reply above the quote" or "start my reply below the quote" (I'm not sure which one is top-quote) --Spoon! (talk) 10:30, 20 April 2008 (UTC)


Thanks! --Grey1618 (talk) 10:32, 20 April 2008 (UTC)

[edit] AutoPlay stopped working

Resolved. Problem was caused by TrueCrypt drivers - fixed by reverting to a System Restore checkpoint created before uninstalling TrueCrypt.

Suddenly, AutoPlay stopped working on my computer. (Windows XP Pro.) When I plug in my USB flashdrive, autorun.inf is not recognized - no custom icon, no custom label, not even the "Choose action" popup. (It doesn't react to music CDs too.)

Registry settings:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]
NoDriveTypeAutoRun = 0x91

Ideas? grawity talk / PGP 11:12, 20 April 2008 (UTC)

I googled your problem and came upon this nice little runthrough with like ten different ways you can enable autoplay. Check it out. By the way, did you recently install a virtual machine emulator? I remember that when I installed VMWare player, it turned off the autoplay for the cd (I think that was because if you put in a cd in the computer, the virtual os and the real one would both want to start reading it). Another thing: you don't actually need the autoplay for anything besides convenience, so if you are completely unable to turn it back on, you can always open My Computer, and right click the cd-drive and instruct it to run the software that should have been automatically played. --Oskar 12:07, 20 April 2008 (UTC)
I did install VirtualPC 2007 (Microsoft), but that was loong ago (~2 months), and the Auto* thing stopped working a few days ago.
By the way, I don't use AutoPlay for CDs - I use it for my USB drive, and I can't "right click the drive" as you suggest - the "AutoPlay" option doesn't even appear.
Finally, if I ask how to fix a thing, that means I do need it, for this or that reason.
--grawity 18:22, 20 April 2008 (UTC)

[edit] satellite communication

expalain how the satellite communicates with our pc/server

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misevaluation, but it is our policy here to not do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn how to solve such problems. Please attempt to solve the problem yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. Thank you. Kushal 14:17, 20 April 2008 (UTC)
PS: I would suggest you to check Satellite Internet access but it seems to be lacking. Hopefully, someone will get the article fixed by the time you read it. Kushal 14:17, 20 April 2008 (UTC)

[edit] Sandisk Sansa c250 microSC capacity

Do you know what the maximum capacity of microSD that a SanDisk Sansa c250 (the first V1 version, I believe) will take? The Amazon does not really help. A buy.com article suggests that the capacity is 2 GB.

However, I am still curious. What determines the maximum capacity of the card the microSD slot will take? Wikilinks are welcome. Kushal 15:34, 20 April 2008 (UTC)

SD cards had to be changed when the capacity exceeded 1GB. Older electronics that were made before the change cannot identify a size of 1 GB normally. You can find an excellent description here especially down the page here hope this helps--Pewwer42  Talk  16:11, 20 April 2008 (UTC)

Note that there are two issues here (as mentioned in the pages above). If a device is not SDHC, then it cannot accept a card larger then 2 GB. While there are some 4 GB cards which are not SDHC, they don't comply with any spec and so are likely to have dodgy compatibility. 2 GB cards do comply with newer revisions of the SD spec so most modern devices should be able to accept 2 GB cards even if they don't support SDHC. Nil Einne (talk) 17:19, 20 April 2008 (UTC)
How can I find out if my device is SDHC? Thanks. Kushal 12:22, 23 April 2008 (UTC)

Thank you for the responses. Do I understand it correctly when I say that Secure Digital format was broken to go from 1 GB to 1+ GB. Then, it had had some changes made from SD to SDHC to go from 2 GB to 2+ GB. If the device recognizes SDHC, can it potentially use 4+ GB microSD cards? Kushal 11:40, 21 April 2008 (UTC)

Uh, "broken" is really a little strong, but you're right; it doesn't work. Secure_Digital_card isn't as clear as it once was when the article was smaller, but the bottom line is that the SD standard was created back when cards were much smaller, and the standard ends at 1GB. This was due to number-size limits (as in "if you count on your fingers, you can't count past 10. You have to start using your nose, or an elbow, or SOMETHING else, to count past 10).
Several companies have extended the standard to make larger 2GB and 4GB cards, but there is no guarantee that a standard SD reader can handle those larger cards. The SDHC standard has backwards compatibility as a requirement, so an SDHC reader can read any SD (up to & including 1GB) card, and any SDHC (4GB & larger) card, but it's rather hit or miss if anything can read a particular 2GB or 4GB SD card. In my daily work I tell people if you have a "Fred's Card Company" 2GB SD card, the only reader you can depend upon to read it is a reader also made by "Fred's Card Company", that understands the particular things they did to make their 2GB card. Other brands may read it; they may not. -SandyJax (talk) 14:58, 21 April 2008 (UTC)

[edit] VPN for getting around ISP throttling

I'm trying to help a friend who's having problems with ISP throttling of P2P in particular eMule (BT isn't so bad for some reason). Changing ISP is not an option since the ISP is basically a monopoly and complaining also goes no where. I've tried various obfuscation options but it doesn't seem to help much. From what I've heard, using a VPN might. So I'm looking for reasonable cheap VPN services which provide access to the internet via the VPN.

Bandwidth doesn't have to be much since it's only a 1 mbit connection. Data should hopefully be at least 50gb/month. Also it's important that you can pay monthly in case 1) The VPN disappears or otherwise craps out 2) The ISP starts blocking or throttling access to the VPN. 3) Kad obfusication in eMule helps, it only just came out in a public beta and with so few nodes using it, it's probably not much use, perhaps things will improve as more nodes use it.

This is obviously going to increase latency, but my friend plans to set it up in a way so that only P2P (probably only eMule) uses it so it doesn't matter so much. Also given the price, my friend isn't expecting it to be perfect provided it's sufficiently better then what he's using at the moment to make it worth it. Obviously a free trial is ideal, to make sure it's actually going to help. And PayPal or some other form of payment which doesn't involve my friend handing out credit card details is a must. Finally, anonymity isn't the most important thing here since this isn't the primary purpose but my friend would prefer to avoid anything with an extremely dodgy background.

So far the only one I've really come across with IMHO a reasonable price (EUR5/month) is Relakks (https://www.relakks.com). They've received some pretty crap reviews in the past especially about the inability to contact any form of support but I guess that's what you get for the price. There's also [2] but they're for sale and haven't been accepting new signup for a few months. I've also come across a few semi/locally run (local for my friend I mean) options [3], [4], [5], [6] but they're more expensive and whether they're better then Relakks I'm not sure. Also since they're targetting this ISP in particular, I'm a bit concerned my friend's ISP may likewise target these VPNs, e.g. by throttling connections to the VPN server.

Anyway are there any other options I'm missing that anyone is aware of?

Nil Einne (talk) 18:35, 20 April 2008 (UTC)

Also found [7]. Similar price to Relakks but sound a bit dodgy to me. Absolutely no information about where they're located on the main site. In the blog, [8] they claim to be from the UK but their English seems pretty crap for a UK company. At the very least, it looks like they outsourced their website Nil Einne (talk) 21:06, 20 April 2008 (UTC)
Also, if you have an account with SSH login somewhere outside the ISP, you can tunnel (a.k.a. port-forward) all your applications over it, and your traffic will go through the tunnel. --Spoon! (talk) 23:06, 20 April 2008 (UTC)

[edit] APL Keyboard Layout

Suppose I wanted to quickly change key assignments from qwerty to the APL layout in Windows. How would I go about this? Is there an input language file for this? Redoubts (talk) 19:58, 20 April 2008 (UTC)

From Google I found this [9] Nil Einne (talk) 20:14, 20 April 2008 (UTC)

[edit] 301 redirects

I've been fiddling around with my personal website a tad and moved my blog, which used to be in the domain root, to /blog/. Unfortunately, I haven't really thought out redirections too well. At the moment, I've just replaced index.php in my root with this:

<?php header("HTTP/1.1 301 Moved Permanently"); header("Location: http://saxsux.me.uk/blog/"); exit(); ?>

But, it means that none of the old URIs for my blog posts (which were index.php/blog/whatever) work any more; the redirection just takes people to the front page of my blog. Is there any PHP (or .htaccess) magic I can weave in order to make index.php/blog/* redirect to /blog/*? Thanks :) --saxsux (talk) 20:41, 20 April 2008 (UTC)

Do you have mod_rewrite for your server? --antilivedT | C | G 05:16, 21 April 2008 (UTC)
I do. --saxsux (talk) 12:33, 21 April 2008 (UTC)
I´m not that acquainted with mod_rewrite but I think something like the following in your httpd.conf or an .htaccess file.
RewriteEngine On
RewriteBase /blog
RewriteRule  ^index.php/blog/(.*)$ /$1 [PT]
Or you can use the alias way, but AFAIK it only works in httpd.conf.
Alias /index.php/blog/ /physical/path/to/your/blog
Try it out and see which way works, or what stupid mistakes have I made in the syntax =). --antilivedT | C | G 22:34, 21 April 2008 (UTC)
Check out RedirectMatch. It lets you redirect based on a regex - a bit like RewriteRule but with redirection rather than rewriting. — Matt Eason (Talk • Contribs) 08:23, 22 April 2008 (UTC)
Oh, scratch that - a standard Redirect in .htaccess will do exactly what you want. — Matt Eason (Talk • Contribs) 08:30, 22 April 2008 (UTC)
Matt - that works perfectly. Thanks! Thanks to antilived too. :) --saxsux (talk) 19:11, 22 April 2008 (UTC)