Wikipedia:Reference desk/Archives/Computing/2010 April 9

= April 9 =

Hard Drive Cleaner
I wanted to sell my computer, but I don't want the buyer or anyone else to have my personal information, bank records, social security and so forth, could someone recommend a good cleaner for the hard drive? —Preceding unsigned comment added by 71.147.7.50 (talk) 00:12, 9 April 2010 (UTC)
 * DBAN--Chmod 777 (talk) 00:54, 9 April 2010 (UTC)
 * Buy a new hard drive and install it in the computer before you sell it. Since the new drive will probably be an upgrade in capacity over the old one, you can charge a little more for the computer.  Save the old drive as containing a backup copy of your files.  You can never have too many backups, and the computer buyer gets a new drive that has never been in contact with your data.  66.127.52.47 (talk) 21:47, 9 April 2010 (UTC)

laptop power brick going eeeeeeeeeee
I've got an oldish (4 years) Uniwill laptop that has a massive powerbrick. I've noticed that it now makes an ever so slight and extremely high-pitched 'eeeeeeeeeeeeeeeeeeee' sound while plugged-in. Most other people can't even hear it. I'm certain it's coming from the brick. Is this indicative of a slow death? Should I be concerned about it bursting into flames? Is it ok to continue using if no other problems arise? 218.25.32.210 (talk) 01:27, 9 April 2010 (UTC)


 * Does it get hot ? If not, it's probably safe, but why put up with the annoyance ?  I'm sure you can get a replacement relatively cheaply. StuRat (talk) 01:48, 9 April 2010 (UTC)


 * Even if it does get hot, that doesn't say much. A lot of power bricks get quite warm during operation, to the point where they can be uncomfortable to handle. &mdash;ShadowRanger (talk 01:51, 9 April 2010 (UTC)


 * The sound you're hearing is in a range that most people lose the ability to hear around the age of 25 (varies a bit, and can be lost much earlier with long term exposure to excessive noise). The number of causes of that noise are too numerous to make any hard and fast recommendations though. I notice it more than most others (because it causes me pain; I'm a bit oversensitive), and I've found that the noise corresponds to a failing fluorescent light bulb, and overclocked and overtaxed graphics card, and any CRT television (particularly when it has no input to override it), getting worse as the CRT ages. I've never heard a power supply do it though. I doubt you're at risk of it bursting into flames; worst case I suspect it would just fail on you. If it doesn't bother you, I wouldn't worry about it too much. &mdash;ShadowRanger (talk 01:51, 9 April 2010 (UTC)


 * I always thought that noise was the power going through whatever the device is. I have a phone charger which has a transformer which does this. Chevymontecarlo . 06:50, 9 April 2010 (UTC)


 * I believe the transformer is the problem here, too. Smaller transformers, like the type in a "power brick", tend to hum at higher frequencies.  Here's a discussion of some of the causes: . StuRat (talk) 13:11, 9 April 2010 (UTC)


 * Check the manufacturer's web site to see if there is a recall. ---— Gadget850 (Ed)  talk 17:33, 9 April 2010 (UTC)
 * The usual cause of that sort of noise is an inductor working its way loose inside the brick. They are normally covered with a blob of glue to stop them from vibrating.  Power supplies do catch on fire sometimes.  I'd replace it if it were mine. 66.127.52.47 (talk) 21:49, 9 April 2010 (UTC)

Question About Artificial Intelligence Programs
I'm not sure if these are classified as AI programs per se, but I remembered a programming contest where programs tried to stay in memory and delete an opponent program from memory/RAM. Does anyone know any websites/information about this? —Preceding unsigned comment added by Andyyee (talk • contribs) 02:36, 9 April 2010 (UTC)


 * Core War? PrimeHunter (talk) 02:45, 9 April 2010 (UTC)

I want to have my own bussines but i don't have much money, which is easier and cheaper?
I want to build something commercial, right now i don't have much money because i'm a foreign exchange student(Mexico) and i don't have much technical skills and i dont want to pay someone to build a website for me because it cost too much.so i want to build something easy and simple because of my lack of technical skills so which is easier and cheaper to build: a comercial website,a social network or a comercial blog. I'am not working right now so i have free time.thank you —Preceding unsigned comment added by 12.175.88.233 (talk) 02:50, 9 April 2010 (UTC)


 * A blog, because you can use free software like Wordpress, or services like Blogger. But it's unlikely you'll make money from this.  To make money with a blog, you usually have to invent some way to get millions of people visiting regularly, and sell advertisements to advertisers.  I think instead you should think about what career you want to have in ten years and maybe take an entry level job at a firm in that business, in order to gain experience so in a couple of years you can get promoted or take a higher-level job at another company in the field ... until you're confident in your mastery of the field and can start your own business in that field.  Comet Tuttle (talk) 03:11, 9 April 2010 (UTC)

A commercial website would be the most expensive choice- even if you decided to build it yourself you'd have to pay to learn HTML and stuff, and you'd have to pay for webpage creation software too, as well as site hosting fees. I'm not sure how a social network would work. Chevymontecarlo. 06:52, 9 April 2010 (UTC)
 * Learning HTML is free if you do not value your time. Emacs (or any number of other text editors) are free (and Free!), as are many web site frameworks. Hosting costs money, but unless you have massive traffic or need complex back-ends (that you wont get on blogs or networks, anyways), the cost is very low. I don't even know how much I pay, but it's single-digit Euros per months. --Stephan Schulz (talk) 09:20, 9 April 2010 (UTC)


 * I'd post on Craig's List. Make some business cards, too. I made some in Microsoft Publisher and printed them on my inkjet on business card paper. Give them out to everyone you meet. Put them on bulletin boards all over the place. You could also make posters, although most of them will get torn down immediately, thereby making them useless. Web sites are almost useless for startups, too, in my opinion. Unless your business has a unique name, your site won't rank very high in Google results. A web site can make your business seem larger and more established than it is. But you have to make it look good (i.e. pay someone very good at making them) to trick people. So if you're just starting out, I wouldn't worry about a site, yet. Most of your business will be return customers and word of mouth, anyway. I haven't attracted any customers with my site. I've never had someone call me and say, "Hi. I saw your site. I'm interested in ..." It just doesn't happen that way for small businesses. Maybe large businesses, but not small ones.


 * By the way: what kind of product or service are you selling?--Chmod 777 (talk) 07:43, 9 April 2010 (UTC)

Before anything you need a clear idea of what it is you are going to provide people (Service or product). There a billion web-pages but very few 'earn' money, most will exist because of the love of their creator. The ways to make money on a website? Content for sale that people want to buy (subscriptions - e.g. the FT website), high volume of people viewing so you can sell advertising space or sell a product on the site that pepople want to buy (e.g. amazon). It's a very difficult thing though and for every Google-billionaire there are hundreds of thousands (probably millions) of people making nothing out of it. To be fair though, setup costs aren't huge and risk-wise you can limit how much you spend so it's pretty 'low risk' business wise 194.221.133.226 (talk) 15:02, 9 April 2010 (UTC)

Wanting to run a Servlet locally with little prior experience
I'd been poking around with various technologies and gravitated towards a Servlet for a project. There are a number of reasons why a Servlet is better than other alternatives, but the major drawback is I have no idea how to run one. I just want to run it locally for a proof-of-concept... maybe a few clients over the LAN in a demo would be the most extravagant it would get. The problem is I have no idea how to get from Java source to a Servlet running on localhost. I played with GlassFish v3 and the Glassfish Tools Bundle for Eclipse, but it seems like there's very little integration between the two.

On to the question, could anyone provide some advice for finding an appropriate and up-to-date tutorial for hosting a simple Servlet? I'm not terribly attached to GlassFish, though I suspect it would be simpler than what I remember of pulling out my hair over Tomcat in university. The biggest obstacle is I just have no idea how to get a Servlet compiled and jammed into a web server... Eclipse doesn't even want to admit that there exists a javax.servlet package. Thanks in advance. BigNate37(T) 12:35, 9 April 2010 (UTC)


 * I've developed J2EE web applications in both Eclipse (in the form of IBM's WebSphere kit, non-free), and NetBeans, (free). In my experience, the free NetBeans tools integrate better with GlassFish.  One of the biggest mistakes is mixing up the Java SE and Java EE compilers - make sure you have a full J2EE SDK installed.  Sun's Java EE SDK is the best bet.  Next, get your Eclipse or Netbeans environment set up to use the EE SDK as its default JRE and compiler.  If you use NetBeans, these tutorials will help.  Out of the box, you can run a NetBeans "New Servlet" wizard, and have a demo servlet running in a debug-version of GlassFish in about 3 or 4 minutes.  Exporting the entire archive in the form of a JAR, WAR, or EAR file is a little more configuration-dependent, but there are export wizards.  Usually, this involves exporting your program as an archive and dropping it on the server, and possibly running an install or configure script (for example, to specify locations of other web services like databases your application/servlet wants to connect to).  Nimur (talk) 16:14, 9 April 2010 (UTC)


 * Awesome, I'll see where I can get. I've just been poking and prodding Tomcat all morning. Thanks! BigNate37(T) 16:17, 9 April 2010 (UTC)


 * Success! I now have a sample Servlet running locally. I can commit to using Java for my project and when the time comes, following the example that I have working will be a simple mechanical activity. Thanks Nimur. BigNate37(T) 04:50, 11 April 2010 (UTC)

Online computer
Say for example I was traveling and used a remote desktop program to connect to my home computer every now and then. I could then set up programs and stuff on the home computer and they'd keep running even when I disconnected from the remote desktop program. However, I am unable to leave a computer running at home when I go traveling. So, are there any online services that offer you a basic Windows system that you can connect to anywhere in the world and would keep running your programs even when you disconnected? 82.44.54.207 (talk) 14:44, 9 April 2010 (UTC)


 * You need to be specific about what type of programs you want to run on those remote servers. For example, there certainly are simulation-type games where food grows, etc., even while you are logged out. StuRat (talk) 14:48, 9 April 2010 (UTC)


 * Wake-on-LAN is what you're after. It's possible for a shut-down PC to be turned on remotely (they do it at my office for essentially upgrades and prevents them having to ensure everyone leaves their pc on). 194.221.133.226 (talk) 14:55, 9 April 2010 (UTC)


 * Sorry just re-read your question, don't think that's what you're after. 194.221.133.226 (talk) 14:57, 9 April 2010 (UTC)


 * Yes, try googling for windows vps (Virtual Private Server). -- Coneslayer (talk) 15:05, 9 April 2010 (UTC)
 * Thanks. A bit expensive but useful to know they exists, and the right terminology. Thank you 82.44.54.207 (talk) 16:17, 9 April 2010 (UTC)
 * Reading what you've written, perhaps you are looking for portable programs that you load into a pen drive and take with you? 78.147.131.74 (talk) 19:34, 9 April 2010 (UTC)
 * I use portable programs all the time :) but for some things they need to be left running on an active computer —Preceding unsigned comment added by 82.44.54.207 (talk) 22:19, 9 April 2010 (UTC)

iPhone OS 4.0 with multitasking
Does anyone know if iPhone OS 4.0 will allow you to run multiple instances of the same app? If I go to the home screen and click on an app that's already running, does a new instance get created or do I get directed back to the existing instance? I've been following Apple's announcement since yesterday but haven't seen this discussed. A Quest For Knowledge (talk) 15:39, 9 April 2010 (UTC)


 * OS X will not let you run multiple instances of the same application, generally speaking. (Starting an .app file of a program with a existing instance will just give that existing instance focus.) I would be surprised if the iPhone OS was different in that regard (especially if they aren't mentioning a difference). --Mr.98 (talk) 16:55, 9 April 2010 (UTC)

Wiki edit tags
This Q applies to Wikipedia, but also to the wiki world, in general. The edit tags for a section always seem to be at the top, while I've usually just finished reading the section, and am thus at the bottom, when I want to edit. So, I scroll up to the top, try to find the edit tag for my section (which I sometimes miss), then it puts me at the top of the section, when I want to add to the bottom. So, now I must scroll down again. My idea is to have edit tags at both the top and bottom of a section, like so:

[Edit ↓]

Content...

[Edit ↑]

The top edit tag would work as it does now, but the bottom section edit tag would place you at the bottom, where most people would want to add text. So, does any other wiki do something like this ? StuRat (talk) 17:01, 9 April 2010 (UTC)


 * Edit buttons at the bottom could be confusing when you have multiple levels of headers (sections, sub-sections, sub-sub-sections). -- Coneslayer (talk) 17:08, 9 April 2010 (UTC)


 * Good point. StuRat (talk) 18:05, 9 April 2010 (UTC)


 * It would be easier (in my opinion) to add a hover function. When hovering an otherwise non-clickable section of text, it will get a slight highlight (perhaps a slightly yellow background).  Then, if you click, it will trigger the edit function on that section.  Then, no matter what part of the section you are in, you click a non-link and you go into edit mode. --  k a i n a w &trade; 17:21, 9 April 2010 (UTC)


 * WYSIWYG editable wikis exist, but MediaWiki (which powers Wikipedia) is not one such software. This is probably for both historic and practical reasons - a high-volume site like Wikipedia benefits from a user-interface paradigm that "slows down" editing (at the expense of ease-of-use).  Nimur (talk) 17:55, 9 April 2010 (UTC)


 * I'm not so sure. The additional time it takes to find the spot where you wanted to edit makes an edit conflict more likely, and then everyone's edit escalates from section edits to page edits, causing more probs. StuRat (talk) 18:01, 9 April 2010 (UTC)


 * I use a home-made database where double-clicking on text allows you to edit it. It's useful a lot of the time, but I am used to it accidentally going into edit mode very regularly (if I want to click and highlight and copy something, 9 times out of 10 I will accidentally or purposefully double-click it and end up in edit mode). For my purposes it doesn't matter much—it's just a homemade database and I'm the only one using it, so I am just used to how it works—but I think it would be utterly disastrous for something with as many users as Wikipedia. Most people who use Wikipedia don't want to edit it—they want to read it. (Most of even my own using of it—and I feel free to edit liberally—is spend reading and not writing.) --Mr.98 (talk) 20:17, 9 April 2010 (UTC)

I couldn't edit
Turns out the problem was the computer, not Wikipedia. Vchimpanzee ·  talk  ·  contributions  · 22:05, 9 April 2010 (UTC)

What's still running?
On Windows systems, what's still running when no one is logged in? For example, if I configure some script to , do I actually have to stay logged in overnight for it to happen?

DaHorsesMouth (talk) 23:25, 9 April 2010 (UTC)


 * If memory serves, when you create a job in Task Scheduler, there is an optional "run as" field. If you fill that (with your own login) then it should run when no-one is logged in (or when someone else is logged in). Beware of running some job that actually requires a GUI application, as this will (I think?) fail. Debugging this kind of thing (as with its unix counterpart cron) can be a bit of a pain. -- Finlay McWalter • Talk 23:32, 9 April 2010 (UTC)

Bioshock stability issue
I know I should've been asking other forums for this, but does anyone know a solution to my problem? You see, whenever I play the game (on XP compatibility, running as admin and on Mono audio), it goes out well for five minutes, but hangs after a while. I'm using Windows 7 Ultimate 32bit, Realtek HD audio, and an Nvidia 8400GS. Blake Gripling (talk) 23:38, 9 April 2010 (UTC)
 * You shouldn't need XP compatibility mode or admin privileges (I've run it under Vista x64 without compat settings). And running in Win7's full XP compatibility mode means running in a VM which would cause all sorts of issues. &mdash;ShadowRanger (talk 00:04, 10 April 2010 (UTC)
 * Indeed Bioshock is clearly somewhat designed for Vista (and therefore Windows 7) since it's a DX10 game, DX10 of course is not officially supported on XP. A 8400GS is a fairly weak card so I don't know if you'd actually want to run in DX10 but the point remains you most definitely should not be running in XP compatibility (in fact I would avoid that in games unless your sure it's needed) Nil Einne (talk) 00:38, 10 April 2010 (UTC)
 * Tried running sans compatibility and it just gives me an error message saying that "BS has encountered a problem" or something. I've heard of so many Der Untergang-style complaints about this. Any ideas? Blake Gripling (talk) 02:36, 10 April 2010 (UTC)


 * OK, some forum dude suggested that I should run the game on DirectX 9 mode. Doesn't seem to freeze anymore, I guess. Blake Gripling (talk) 00:29, 11 April 2010 (UTC)