Wikipedia:Reference desk/Archives/Computing/2009 January 4

= January 4 =

some games are not playable
I have a p4 with core 2 duo processor but I have only 40 Gb hard disk formated  with FAT system (because my 250 GB hard disk is out of order). I have downloads the games "Mad dogs on the roads" and " Lost road races " and installed but I can not play them on my computer.games starts as usual and ask for the name, "  new game or ---" then first level sign appear but after that an error message appear .and for one of them it appears that "memory access denaid " what should be the problem ? —Preceding unsigned comment added by Khubab (talk • contribs) 00:27, 4 January 2009 (UTC)
 * I have never heard of these games, and I doubt anyone else on the RD has, but they sound like they're related. The same error is probably affecting both, whatever that is. Try to find the games' tech support forums or a contact email address or whatever there is and ask the question there; you'll most likely get a better response if you specifically target people who know about the games. 24.76.161.28 (talk) 01:06, 4 January 2009 (UTC)

internat explorer sign is not " e " like
In start menu, the picture within the "internet explorer" is changed from sign of "e " to an other sign. what should be the problem and how can i get original sign. —Preceding unsigned comment added by Khubab (talk • contribs) 00:37, 4 January 2009 (UTC)


 * Try right-clicking on the icon in the start menu; going to 'Properties' on the menu that comes up; then clicking on 'Change icon'. If this doesn't work, you may need to tell us which versions of Windows and Intternet Explorer you're using.  TSP (talk) 00:40, 4 January 2009 (UTC)


 * The sign is called an icon. What does the new icon look like? — Matt Eason (Talk &#149; Contribs) 01:22, 4 January 2009 (UTC)

By right clicking the icon "properties "does not appear but "internet properties". I m using windows Xp service pack 2, and internet explore may be latest (I donot know).Icon is a rcangular shaped ,small curled at one end ,and inside it a square with three small figure in it ,(this is they same icon for which windows does not know which program can open this ).My internet explorer is working properly. —Preceding unsigned comment added by Khubab (talk • contribs) 01:43, 4 January 2009 (UTC)

wikicode source
How would you write this infobox from scratch in wikicode? I can't merely click "view source" because the source transcludes a lot of other stuff, so it's not clear what the basis for this in wikicode is. Thanks --VectorField (talk) 02:00, 4 January 2009 (UTC)
 * I'm not going to answer your question, since I don't like looking at infobox's code, but I will say that it depends crucially on some stuff in MediaWiki:Common.css and MediaWiki:Monobook.css. Algebraist 02:05, 4 January 2009 (UTC)
 * I ask because I would like to replicate the code for my own wiki without having to replicate the monstrosity that is infobox. --VectorField (talk) 02:08, 4 January 2009 (UTC)


 * Fundamentally you can have a div that's float=right, or a table the same. Inside the div (or the table) you just have a bunch of rows, spaced and formatted in html as you want. To fill in the individual rows, you use MediaWiki's normal substitution mechanism. -- 87.112.6.240 (talk) 02:21, 4 January 2009 (UTC)

domain pointing
(Wow I should know this...) I use Apache for hosting, and Godaddy for registrar-ing. How do I make my domain name point to my Apache server on my IP address? Should it be "forwarded" or using a "nameserver?" flaminglawyerc 02:39, 4 January 2009 (UTC)


 * You need a DNS (dynamic name server) - sometimes the registrar will offer you that service (at a price) - generally, if you host your site at a web hosting service - they'll provide the nameserver. There are a many nameservers you have to pay for - and a couple of free ones.  You could (in theory) make your own nameserver - but I looked into doing that and frankly, it's a bitch.  When I ran my own site from home I used GraniteCanyon - who offer a free public service.  However, it was patchy and would 'disappear' for a couple of days at a time several times a year.  Now I host my site with Dreamhosts.com and they handle all of that nastiness for me as a part of the $10 a month I pay them for hosting my site. SteveBaker (talk) 04:08, 4 January 2009 (UTC)
 * Ok, I set one up at freedns. Now what? flaminglawyerc 04:39, 4 January 2009 (UTC)
 * Nevermind, that site was not what I thought it was. Still looking for free nameservers. flaminglawyerc 06:12, 4 January 2009 (UTC)
 * FreeDNS does have free DNS hosting. See the "domains" section. --grawity 15:22, 4 January 2009 (UTC)


 * Yes, but I don't like it as much as the new one I found, EveryDNS (which I am using). So now what? I have the table on the right on my "domains" page, which seems right, but it's now showing my index.html page (the default "It works!" page). Instead it has a network timeout. When I go to http://localhost/ it works, but not when I go to my website.  flaminglawyerc 23:51, 4 January 2009 (UTC)
 * DNS records have to propagate through the Internet from one server to another - and that can take several days. Be patient! SteveBaker (talk) 19:18, 5 January 2009 (UTC)
 * darn. flaminglawyerc 23:13, 5 January 2009 (UTC)


 * The other problem is that if you're using a NAT router, it might not support NAT loopback -- you'll know this is the case if, after a few days, you're the only one who can't use your domain to access your computer. The workaround is to set up a DNS server and resolver on your home system. --Carnildo (talk) 22:54, 5 January 2009 (UTC)

.NET Passport and cursors
I've got two questions: --Crackthewhip775 (talk) 02:59, 4 January 2009 (UTC)
 * 1) How do I disable the .NET passport on my User Account? Because I already have a Windows Live ID separate from it.
 * 2) Can anyone recommend a safe website where I can download cursors?
 * For #2, cursormania is the only safe one that I know of. Unless you're interested in building your own cursors, in which case you could use one of the things on here which are on Download.com so I'm guessing they've been security-tested. flaminglawyerc 03:21, 4 January 2009 (UTC)
 * Web Of Trust (a Firefox plugin) says cursormania is a badguy. —Tamfang (talk) 09:09, 4 January 2009 (UTC)


 * 1) Windows Live ID is the same as .NET Passport.
 * 2) If you want something nice, the cursors category on deviantART is nice. --grawity 15:21, 4 January 2009 (UTC)

Safe Search

 * As far as which sites are "Safe", there are several tools available that monitor which sites are safe. I've been pleased with siteadvisor (McAfee).  I know their AV software has taken some hits lately, but their Site Advisor tool seems worth the download to me.   When you do a search (say in Google)... it marks each result with green, yellow, red, or gray buttons.  It is also a small toolbar that changes colors depending upon the site you're on.  I'm sure there are other tools available as well, but I didn't look past this one cause it works for me.  Ched (talk) 18:01, 4 January 2009 (UTC)
 * Thanks for the suggestions, especially the one deviantART and the McAfee site advisor, though I have something similar to it, Web of Trust, as Tamfang was talking about. --Crackthewhip775 (talk) 20:39, 4 January 2009 (UTC)

Digital filter software.
I should perhaps be asking this on the math or science desk - but I'm going to try here first because I suspect that if I get an answer, it'll be one that I can understand!

I'm writing a simple music synthesiser package to run on a teeny-tiny Arduino microcontroller (yes, I am a complete software-masochist!) - I'm trying to emulate a MiniMoog analog synth - and I need to implement an audio filter with a realtime-adjustable frequency cutoff. I need something that's small, fast and uses very little RAM (although I don't mind having some reasonably large lookup tables so long as they are constant).

Does anyone know of a suitable digital filter algorithm for doing that? I've been messing around with simple moving-averages and other filtering techniques I use in the graphics world - but somehow I'm not getting what I need for audio filtering and the realtime nature of the thing on a pathetic little 8MHz CPU with under 1k bytes of RAM is definitely a challenge!

TIA SteveBaker (talk) 04:32, 4 January 2009 (UTC)
 * I've emailed you a copy of some pages from this book that might be relevant. I bought the book some years ago when I was doing some audio programming. I've never tried implementing any filters, but judging by the book, the article Infinite impulse response, with its links, may be of interest. You could also download the source code of Audacity, and see how the filters there are implemented. --NorwegianBluetalk 13:44, 4 January 2009 (UTC)
 * Thanks! That was fairly helpful. I was hoping to find some actual code.  The book suggests something like this:

filter ( input, tunefactor, damping ) {  lowpass  += tunefactor * bandpass ; highpass = input - lowwpass  - damping * bandpass ; bandpass += tunefactor * highpass ; notch    = lowpass + highpass ;  // Optional! }


 * ...but doesn't really explain how I set 'tunefactor' and 'damping' to adjust the rolloff frequency. However, it's short and it adds almost zero delay into the signal path!  Another problem is that this is a 16 bit machine with no hardware floating point support - so everything has to be done in fixed-point math - which is do-able if you know the ranges of all of the internal variables.  If I knew what a sensible range of values for the two inputs were - I'd be able to do the math in 16-bit-friendly ways.  I like the idea of checking the Audacity sources - I'll see what I can find there. SteveBaker (talk) 19:16, 5 January 2009 (UTC)


 * Steve, have you looked into the Max environment? It's (almost certainly) not suitable for what you want to do this time 'round, but I'm sure you'll get into it if you like using Arduino boards.  [ cycle~ ] (talk), 15:39, 4 January 2009 (UTC)
 * That's WAY out of the Arduino's league! I only have ~1kbytes of RAM and 14kbytes of Flash for program storage - and it's a 16 bit CPU without floating point - so everything has to be kept super-simple. SteveBaker (talk) 19:16, 5 January 2009 (UTC)
 * Yes definately; but it's something you may be interested in incorporating into something larger! [ cycle~ ] (talk), 22:45, 5 January 2009 (UTC)
 * There doesn't, as far as I can tell, seem to be an open-source smallscale (microcontroller-friendly) filter package around, so you may well be stuck implementing your own filter FFTs yourself. The trickiest part will probably be getting the FFT to be real-time efficient on such a limited platform (but given the onboard DSP on that device, clearly this kind of stuff is a design target for the AVR). Take a look at the Atmel application note "AVR223: Digital Filters with AVR"  (from this page) which has some of the basics (including how to do multiply-accumulate on their architecture). For a more concrete example, this guy has a simple FFT (I think it's a FIR) on that architecture. 87.112.6.240 (talk) 16:28, 4 January 2009 (UTC)
 * FFT seems a bit of an overkill - and it seems like it's going to introduce a lot of delay (which I can't have) - the Atmel application note is a bit math-intense (why the heck can't they just supply some source code?), but I'll take a shot at working through it. SteveBaker (talk) 19:16, 5 January 2009 (UTC)

Recommend a Rails book
Can you recommend book on Ruby on Rails? I'm a Python developer who came in without doing a CS course. I'm used to Django and want an introduction to Rails (for fun, not work). I've read (and enjoyed) Ruby by Example (ISBN 9781593271480), which covers Ruby basics but not Rails. --h2g2bob (talk) 15:19, 4 January 2009 (UTC)

I can recommend that you stay the hell away from Rails. just google why ("rails sucks" etc). —Preceding unsigned comment added by 79.122.10.173 (talk) 21:28, 4 January 2009 (UTC)

Surely Python is the more fun option. 79.79.69.199 (talk) 04:43, 5 January 2009 (UTC)

Ubuntu to Ubuntu remotes desktop connect
I am trying to help someone setup wireless on their Ubuntu machine. I need to remote desktop to his machine to check everything out. He hooked directly in to his modem and I am behind a router. He did the system > preferences > etc. and checked to allow other people to access his desktop. He gave me his IP. I tried using the GUI VNC application (applications > internet) but it would always come up saying the connection had been closed when I hadn't even connected. (It took quite a while for this to come up so I think it may have been timing out.) I have no idea why this is not working. Any suggestions? TIA, Ζρς ι'β' ¡hábleme! 22:37, 4 January 2009 (UTC)
 * Could it be a firewall issue? Is his modem blocking the VNC port (I don't know what port VNC uses)? Does he have a firewall installed? - Akamad (talk) 01:42, 5 January 2009 (UTC)
 * Maybe (VNC uses port 5900). How could he set his modem up to allow these connections?  Ζρς ι'β' ¡hábleme! 02:06, 5 January 2009 (UTC)
 * That would depend on the modem/router he has. Have a look at this site: http://www.portforward.com, in particular, have a look at this page: . Also check to see if your friend has blocked any ports via software means (such as through a firewall application such as Firestarter). - Akamad (talk) 07:02, 5 January 2009 (UTC)

OpenOffice.org will not quit
Frustrated with MS Office PowerPoint 2008 for Mac, I downloaded OpenOffice.org 3.0 to my Mac with OS X. Now I cannot quit: I get a message: "The application OpenOffice.org failed to quit and is not responding."

What should I do?

L. —Preceding unsigned comment added by 96.255.66.148 (talk) 22:43, 4 January 2009 (UTC)
 * Have you tried force-quitting? Algebraist 22:49, 4 January 2009 (UTC)


 * Ctrl+Click on its icon on the taskbar, select "force quit." Or go to the Apple menu, select "force quit". If all else fails, hold down the power key to manually reboot. --98.217.8.46 (talk) 22:55, 4 January 2009 (UTC)