Wikipedia:Reference desk/Archives/Computing/2006 November 7

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November 7

Video Processors

As an old fogy, I do not understand your newfangled descriptions. Can someone tell me what a video card is in simple words and what it does? —The preceding unsigned comment was added by 71.3.107.52 (talk • contribs) .

For someone who doesn't know, you sure know to put it under video processors. See video card. It processes video, creating images from data. --Wirbelwindヴィルヴェルヴィント (talk) 01:47, 7 November 2006 (UTC)

The video card article is a mess. Let's try something friendlier for fogies.

Decades ago, we put information into computers by punching holes in cardboard, and we got information out by stamping ink onto paper. For elections, maybe that's still a good idea. For daily computing, that's too awkward, too slow, and too limited. Instead we put the information in using an electronic keyboard and a mouse, and we display information on a video screen.

It is a drain on the memory and computing power of the computer itself to present graphical information, so we prefer to separate those functions into specialized hardware. That is what a video card does. We can tell it things like "display this line of text" or "draw this circle" and leave it to do all the rest of the work. Over time, these cards have greatly increased in power, evolving from simple "glass teletypes" to sophisticated 3D graphics engines capable of real-time immersive 3D games.

A typical card includes its own highly specialized computing system, with a graphics processing chip, dedicated memory, an interface to the main computer, and an interface to the video monitor. Some cards are so potent they have their own cooling systems and ways of drawing extra power. --KSmrq^T 03:59, 7 November 2006 (UTC)

Rogers throttling BitTorrent

I'm told Rogers Hi-Speed throttles BitTorrent downloads and uploads and can seriously slow them down. Does anyone know a workaround for this? Will it help if I use Tor? NeonMerlin 03:51, 7 November 2006 (UTC)

Don't use 6881 as your port, if that doesn't help, turn on encryption if your client supports. Tor won't help at all, besides uber-latency. Splintercellguy 04:38, 7 November 2006 (UTC)

You're in for an uphill fight, but yea, start with port shifting, if that doesn't work, then add encrypted packet headers. Continue encrypting until you get un-throttled. Do notice that this comes at the cost of available peers. Also be warned that if your ISP doesn't like BT enough, they'll just turn off all inbound access, which is an unsolvable issue.--Frenchman113 on wheels! 23:12, 7 November 2006 (UTC)

Extract strings from a set of text files ANSWERED

Hey folks

I'm currently faced with a problem where I have a large collection of files that I want to extract strings from. Basically what I need to do is run the same process on each file - they all follow the same format, so a solution that works for one will work for all of them. I suspect that what I want could be done with something like grep or a simple PHP script, but I'm not really experienced with either.

There are two relevant lines in each file that I want to extract and concatenate, then I want to dump all of the resulting lines into a single text file

A simple example would be:

File1.txt:

[Firstname] Bob

[Lastname] Dobbs

File2.txt:

[Firstname] Homer

[Lastname] Simpson

and what I basically want to do is end up with a text file that contains:

Bob Dobbs

Homer Simpson

Thanks --Noodhoog 06:22, 7 November 2006 (UTC)

I'm assuming you're using Linux. Can you define the constraints a bit better ? For example, do you always want to pick the 12th character on up from each line that starts with "[Firstname]" ? I would think you would use "grep", and possible the "cut" and "sed" commands, as well.StuRat 07:10, 7 November 2006 (UTC)

Actually I'm working on XP here, but I'm pretty sure most of the tools like grep are avaliable. In terms of finding the text to copy, I can't really rely on the characters being in the same position within the file each time due to differing length of string, but there are marker 'tags' at both the start and end of the strings I want, so it would be more like [firstname]homer[endfirstname], and I'd just want to copy everything between [firstname] and [endfirstname] --Noodhoog 07:21, 7 November 2006 (UTC)

What's the format of the files? .txt, .xls, etc? Anchoress 07:33, 7 November 2006 (UTC)

Many thanks for your input folks, the problem is now solved. A friend managed to help me throw together a script to do the job :) --Noodhoog 08:03, 7 November 2006 (UTC)

web site

how can i set up a web site that anybody can blog on 71.212.11.62 16:25, 7 November 2006 (UTC)

Maybe setup a wiki? --Wirbelwindヴィルヴェルヴィント (talk) 17:06, 7 November 2006 (UTC)

Lyceum (software) is a good multi-blog platform; there are others. EdC 20:43, 7 November 2006 (UTC)

You could also just establish a community on Livejournal or Blogger. X [Mac Davis] (DESK|How's my driving?) 22:17, 7 November 2006 (UTC)

Installing Downloads

I consider myself 1/6 knowlegable about my MacOSX, but try as I might, I cannot understand what (or how) to copy a folder into the http document directory of my web browser. The download I am trying to make work recomends to copy an entire folder in the http root path of my web server. I have looked under all kinds of help articles, but either wasn't able to understand them, or wasn't able to do as they directed. HELP!?!

Wait a minute, here. What do you want to do, really? Does it have to do with your browser (e.g. Firefox or Safari) or server (e.g. Apache)? (Oh, and please sign your comments with "~~~~".) —Bromskloss 17:54, 7 November 2006 (UTC)

First I think you're confused on the use of the word "Download." Download means to copy data from a remote machine to your machine. This is what I guess is your problem: You found some interesting script on the internet, for example a qmail frontend for perl. It says in the readme to copy it to your web server.. so you try to drag it into your browser or whatever. This is a fundamental lack of understanding of Category:Internet architecture. Your browser merely renders the data that the server machine sends you.. it has no ability to process and run these server-side scripts (which in this case require interaction with qmail, which would be running on a server machine and not your mac). If you really need to make this "download" work, you're going to need to install apache and put it in your htdocs folder. Also any necessary daemons need to be running (like qmail in this case) and of course an interpreter for the language that it's written in. Then start up the server and open your browser. Connect to yourself just like you'd connect to a web site (remember your computer is acting as a web server machine now) by typing the IP address (try 127.0.0.1 or localhost if it's defined in your hosts file) in the address bar. Then the server code will run that "download" that you have --froth^{T C} 18:48, 7 November 2006 (UTC)

C++

What is a good book to quickly learn C++ for someone who

1. knows C very well, and
2. will be using C++ principally for scientific/numerical applications?

Thanks –Joke 17:36, 7 November 2006 (UTC)

Well, the C++ book is fairly comprehensive. I think if you read that, you'll be able to cope with pretty much any application area. EdC 21:08, 7 November 2006 (UTC)

Yes, I have that. It is a little daunting for someone who grew up with the K&R, which you can pretty much memorize. But perhaps I'll just have to sit down and slog through it. –Joke 21:13, 7 November 2006 (UTC)

Learning C++ quickly may not be possible. The syntactic differences are the least of the challenges. The object-oriented thinking is a major re-orientation. Also, the Standard Template Library takes time to absorb. However, if you would be content to use a C++ compiler but essentially write C programs (not recommended!), that should be a quick transition. --KSmrq^T 03:59, 8 November 2006 (UTC)

Yes, I understand that C++, despite being a superset of C, also requires a radical readjustment. I'm not totally unaware of what object oriented programming is, and I already write C programs that work in an object oriented sort of way (i.e. by defining a set of structs and functions to initialize and act on the structs in various ways.) But it looks like it might nonetheless be a long path ahead. The substantial work function (along with the alarming fact that half the scientific and numerical world still seems to use FORTRAN 77 and High Performance Fortran) has kept me from learning C++ for about a decade, but the time has probably come to bite the bullet. It is a little sad that the number of pages needed for a reasonably comprehensive description of the language has gone up by a factor of three or four, but I suppose that is inevitable. –Joke 05:10, 8 November 2006 (UTC)

• Bruce Eckel's thinking in C++ is quite good, you can see it online. O'Reilly Media books are always good. In my opinion the C++ book mentioned above, is a bit to high level for beginners. --Salix alba (talk) 07:55, 8 November 2006 (UTC)

Some Websites Not Loading

If a website wont load, how do I find out if it's my computer or their server? Right now trust.com wont load, and yesterday I had trouble with Wikipedia and with Opera. Is it me, a server near me, or the websites? --Username132 (talk) 18:29, 7 November 2006 (UTC)

Oh, IMDB.com as well. --Username132 (talk) 18:30, 7 November 2006 (UTC)

But while going in through a google link works for IMDB, it doesn't for Trust.. --Username132 (talk) 18:31, 7 November 2006 (UTC)

If you perform a traceroute on the sites in question you can often see exactly where the hangup is. --140.247.250.201 23:28, 7 November 2006 (UTC)

That's a great tip - thanks!

Old Macintosh software/games

I'm writing a piece on decidedly illicit (read: pornographic) mid-80s video games/software. I've found a number of Atari games (some of them shocking), but am curious if anyone recalls any such 'underground' software for the Macintosh, maybe something that was clandestinely circulated. Wiki's software/games list for Macs is extensive but seems to cover the full history of the computer, and I'm targeting only mid-80s. Short of clicking on every game, can anyone offer up anything (provided, of course, such games existed)? Thanks in advance.Wolfgangus 19:58, 7 November 2006 (UTC)

• The box cover for Softporn Adventure (1981) mentions that it can be played on an Apple II Plus, if that helps.

In fact it does, bringing me to mobygames. Thanks very much.Wolfgangus 03:37, 8 November 2006 (UTC)

Blaster virus on Wikipedia-- how long?

How long did the phished/spammed page exist? I can't see anything in the page history. This is in an attempt to clarify the story for TechTree. -- Zanimum 20:19, 7 November 2006 (UTC)

Hi - I can't say how long it lasted, but the phishers were linking to a page oldid, to avoid reversion (linking to a static version of the page). Upon the discovery of this (on the German wikipedia, I believe), the oversight function was used to remove the dangerous versions of the page. Thanks, Martinp23 20:26, 7 November 2006 (UTC)

Site Meter

Hello,

I have added the site meter to my blog. But I do not see any numbers being shown. (i added through html for my beta blogger). Instead I see a logo, which if I click goes to sitemeter.com website - and there I see the numbers; But I need to see the number in the blogsite itself :)

Can someone help me?

Thanks Slmking 20:55, 7 November 2006 (UTC)Slmking 20:54, 7 November 2006 (UTC) slmking

mastercard

Where can I get visa or mastercard gift cards? Are there any stores I can get them at thx

What you want is a prepaid credit card. The difficulty will be getting the name/billing address correct when you purchase the card. It is much easier to buy a store gift card because you don't need the recipient's name. Of course, it is even easier to just give them cash. But, what's the point. Most gift-giving times have now become: "I'll give you $20 and you give me $20. Isn't that great!" --Kainaw ^(talk) 02:38, 8 November 2006 (UTC)

Non Writable DVD+RWs

I have some DVD+RW discs on which I want to burn an image (SUSE LiveDVD) but Alcohol 120% and Roxio 6 both claim that the DVD+RW is non writable. I've tried this with two discs and get the same thing, and I've tried uninstalling the drive in device manager. Perhaps incidentally, the drive is called just 'CD Drive' in My Computer, instead of DVD Writer like I think it ought. However, Alcohol 120% recognises it as a DVD Writer and so did Roxio until I updated the Roxio software, after which it didn't acknowledge the drive at all and says 'please insert a blank disc'. Is there a way I can find out if it's the discs, software or drive, preferably by series elinmination of the software and drive first? My DVD recorder is compatible with DVD+RW type discs. --Username132 (talk) 20:58, 7 November 2006 (UTC)

Are you sure its compatible with *writing* to these discs? If anything, I would think the most recent version of Alc 120 or Nero would support this, if it's possible. --Jmeden2000 21:21, 7 November 2006 (UTC)

Yeah, definately meant to write to DVD+RW. My drive is reviewed here. The LG website doesn't seem to mention it though (I was hoping to try a driver or firmware update maybe). --Username132 (talk) 21:35, 7 November 2006 (UTC)

A firmware update is pointless because the drive already has the latest available firmware version. --Username132 (talk) 01:03, 8 November 2006 (UTC)

Are you sure they're DVD+RW discs? It's the first time that comes to mind over everything else. --Wirbelwindヴィルヴェルヴィント (talk) 09:07, 8 November 2006 (UTC)

Sorry if this is too obvious, but has the disk you are using been burned already? You may need to blank it first. Weregerbil 10:57, 8 November 2006 (UTC)

Yeah, it's blank. I just took them out of cellophane and besides, 'drag to disc' reports it as a blank disc. --Username132 (talk) 11:43, 8 November 2006 (UTC)

Somewhat urgent question about streaming live video

I need to set up a webcam to do the following things:

• it will be streaming live to a projector in another state (but just one projector, and only one time, i.e. I don't need it to be streaming on a webpage and does not need to work well more than once)
• the picture will need to be able to switch live from the webcam image (the person speaking) to a separate powerpoint presentation (though the audio will be the same, i.e. the person speaking)

What's the best/possible way to do this (esp. the latter aspect)? I haven't used this tech before though I imagine that it must be possible to switch between two input signals at run-time, though I don't know exactly where to start in reading up on it. I don't have a camera or software yet at this point but will be purchasing them as soon as I know what it is I really need. Thanks.

Assuming you are using windows machines have a look at netmeeting. Vespine 22:55, 7 November 2006 (UTC)

Window machines, indeed. I'll check out Netmeeting — does it allow you to broadcast just the video without the interface? --140.247.250.201 23:26, 7 November 2006 (UTC)

internet speed is 256kbps,what time it will take to download 200mb ?

59.161.70.40 23:22, 7 November 2006 (UTC)kkgupta

You already asked yesterday. --Wirbelwindヴィルヴェルヴィント (talk) 00:26, 8 November 2006 (UTC)

Around 2 hours, 45 minutes.

Technology behind email hacking

By general knowledge or personal experience, does anyone know if such sites as: http://www.hire2hack.com/ are anywhere near to legit? If so, (without threatening legality, of course) how is this sort of thing possible? I wouldn't exactly call myself computer savvy and a friend mentioned something about the hacker trespassing into the registry or cache of the victim computer and taking the information which makes the process sound really quite complex. Is this a combination of password retrieval and something else? For curiosity's sake only, of course. :) Thanks in advance. Sybil Gray 23:47, 7 November 2006 (UTC)

Judging from this page, they probably use pretty low-tech methods; dictionary attacks, or less, like calling the person up and pretending to be their service provider. Getting access to another computer over the internet is not too hard to do if the person in question is not very tech savvy -- there are many viruses and programs which, if you can convince someone to execute them, will give someone access. However if you have a good firewall, know better than to run programs that will compromise your machine (and don't use software which lends itself to these sorts of programs, i.e. Internet Explorer, Microsoft Outlook, etc.), and are distrustful of other people, then it would be considerably harder. Most things I have read about this sort of "hacking" imply that a large part of it is social — getting someone to tell you their password without suspecting you're going to do anything nefarious with it, for example — rather than special technological tricks, though I could imagine employing both at the same time (i.e. getting someone to run a program which allows you access) for improved effect. But I've never tried such a thing, and am only speculating.

I see. I've never really thought about the social aspect of it, though I hardly think that warrants $150 (the illegal activity, maybe, though). I myself would be a little untrustworthy of a service provider calling me - which would be difficult to play in some cases, where the internet service provider is say, a DSL company, and the intended email of the victim is some independent email provider such as Yahoo or Gmail. Even more dubious would be a "call from Google or Yahoo." Moreover, would they send an email posing as a sort of spam with the program contained virus and expect the victim to download/open/run it? Surely they wouldn't send an email from the customer? Also, what I vaguely know about dictionary attacks seems like it would work, but as far as I knew they only worked on a local level, in one's own computer registry. However, I can understand that remote networks would be accessible, if we're talking about first obtaining the victim's IP address, or loading a virus onto their computer. (Probably not just having an IP address - if that were the case, all of the anonymous users on Wikipedia would be in trouble.) Sybil Gray 07:12, 8 November 2006 (UTC)