Wikipedia:Reference desk/Archives/Computing/2011 March 28

= March 28 =

Using WebGL in Firefox 4
Every time I try watching WebGL examples in demos.mozilla.org I get this message: "Unfortunately, while your browser supports WebGL, your video drivers may be too old. To view any of the demos tagged with WebGL, try updating your drivers at NVIDIA, AMD, and Intel."

I have updated everything I was offered to update after doing this test, but I still get that massage. I also tried to change the settings in 'about:config' (as suggested here), but that 'enabled_for_all_sites' doesn't exists anymore, and was replaced with 'disabled' (which is set to false).

Can it be fixed somehow? Thanks a lot, 212.143.55.119 (talk) 08:47, 28 March 2011 (UTC)


 * Are you sure your graphics card (and its driver, and the operating system) are supported and not blocked by Firefox 4? 118.96.158.177 (talk) 00:37, 29 March 2011 (UTC)


 * Alternatively, you can try "force-enabling" it and see what happens, at the risk of crashing Firefox. See the last section of the linked page. 118.96.158.177 (talk) 00:50, 29 March 2011 (UTC)

Why computer manufacturers disable CPU virtualization capacity by default?
The first time I'm aware of this is on Microsoft website, when I was downloading Windows Virtual PC. After some VMware Workstation installation, I can see all computers, both desktop and laptop, on which I installed it, have virtualization disabled by default. On my laptop (Phenom II N930), the BIOS says something like this: "Hardware virtualization technology is designed for specialized software to allow many virtual machines to run separately from each other. If your computer does not have specialized software, HP recommends this feature being disabled." So is that any bad when this feature is being disabled? By the way, is emulation speed faster when it is enable? I'm a bit lazy to test it myself because even with virtualization enabled, the virtual machine seems too slow for gaming compared to the host. -- Livy the pixie (talk) 10:38, 28 March 2011 (UTC)
 * I can't comment on why they leave it off (maybe they figure that the less users can do with computers, the less they can get into trouble?), but virtualization generally has a pretty small time overhead, since userland code is permitted to run unimpeded (though it occurs to me that there will be a bit of extra time taken for painting things to the screen. If it's poorly implemented, that could be a bit costly.).  Gaming may work poorly because the virtualization software doesn't have good graphics card support.  Paul (Stansifer) 11:20, 28 March 2011 (UTC)


 * Apparently it's because they're afraid (probably unreasonably) of hypervisor-based rootkits. -- BenRG (talk) 21:46, 28 March 2011 (UTC)

Thanks for the info. -- 113.190.212.155 (talk) 04:44, 31 March 2011 (UTC)

32GB DIMM
The only 32GB DIMM I've been able to find is Samsung's M393B4G70AH0-CH9 - which other manufacturers make 32GB DIMMs, and which manufacturers have motherboards which support 32GB DIMMs? Thanks as always. Rocketshiporion ♫ 11:56, 28 March 2011 (UTC)


 * I don't think anyone else is making them, or that you can even buy the 32gb's yet. I remember reading when they were announced, they use some very fancy packaging techniques as well as ultra-dense chips.  I saw your motherboard question further up and I'm drooling over the machine you seem to be trying to build.  How much are you planning to spend on it and what are you planning to do with it, if you don't mind my asking?  75.57.242.120 (talk) 19:49, 29 March 2011 (UTC)


 * I'm trying to keep the cost under SGD50K if possible, but no more than SGD60K at the maximum. It's for running GNU Octave in parallel; although Octave doesn't currently support MATLAB's  function, I'm banking on it that the FOSS community will implement an equivalent for Octave soon. It's simply unaffordium to get MATLAB 7 and/or MATLAB Distributed Computing Server - the price of the license fees is more than the cost of the hardware itself!  Rocketshiporion ♫ 10:24, 30 March 2011 (UTC)

what's the max proces name lenght on winxp
t.i.a. --Ulisse0 (talk) 12:40, 28 March 2011 (UTC)


 * In .NET, the process name is a Property value that is treated as a System.String - so it can have arbitrary length. See Process Name reference from MSDN.  If you are using the core WINAPI functions, you provide the process name as a long pointer in the CreateProcess function.  For most purposes, your Process Name will match a subset of your command-line, which is explicitly limited to a 32k character array: "The maximum length of this string is 32,768 characters, including the Unicode terminating null character."  Is there any reason you would want exceptionally long process names?  Nimur (talk) 04:33, 30 March 2011 (UTC)
 * thank you! The reason i that I wrote a little tool to monitor the tasklist --Ulisse0 (talk) 08:09, 30 March 2011 (UTC)

Non recognition of D:Drive
I have recently installed Windows 7 Ultimate on a Dell Dimension 1100 and I am unable to get it to read anything in the D:drive (CDs, DVDs etc) Can someone please give me an idea about how I can activate this drive. I have completed all the menus on the Control Panel which ask how I want my pictures, DVDs and CDs to initiate - and still nothing. Thanks in advance. Caesar&#39;s Daddy (talk) 15:05, 28 March 2011 (UTC)


 * Did the drive appear in Windows Explorer? In the Device Manager? When you first turned on your computer (usually under "IDE Devices" list)? What happened if you insert a disc into the drive? Did the drive spin or make a sound? 118.96.158.177 (talk) 00:37, 29 March 2011 (UTC)


 * Not in Windows Explorer or in Device Manager, but there is an A: drive(floppy disc drive) identified which I don't actually have as hardware. A disc does nothing when inserted, no noise, no spinning, a couple of blinks of the indicator light by the drawer and then nothing. Caesar&#39;s Daddy (talk) 08:48, 29 March 2011 (UTC)


 * Either Windows is not detecting the drive because the appropriate driver is not available (very unlikely for an optical drive in a modern operating system), or there is a problem with the drive, the data cable connecting the drive to the motherboard, the motherboard's IDE/SATA port, or the motherboard's IDE/SATA controller (more likely). 118.96.165.228 (talk) 14:28, 29 March 2011 (UTC)


 * Have you went to Disk Management? Type in the search bar in the start menu, hit enter, then select properties for your DVD drive. If you can't see it, I'm guessing it's not plugged in properly. General Rommel (talk) 09:03, 29 March 2011 (UTC)


 * Because it was working before (or at least I assume that from what you said) it sounds like a software issue and it's probably an issue with the filter drivers, see here for more information and a fix - Be sure to reboot afterwards though! That link offers an automated fix or a manual registry fix, I've only ever ran the registry fix method, but the automatic one should do the same thing. Yes I know that link is for Windows Vista, but XP had the same problem/solution and I don't see why W7 would be any different either, it's not replacing any files just removing some values from the registry so I'd recommend trying it.  ZX81    talk  15:57, 29 March 2011 (UTC)
 * Thanks for those excellent responses. I finally solved it by downloading the driver from the MS website, so extra thanks to ZX81. Caesar&#39;s Daddy (talk) 17:59, 29 March 2011 (UTC)

Saving a document in Microsoft Office Word 2007 as a "read only" file
Is there a way to save a document so that it becomes a "read only" file, one that cannot be edited by others? I have a Word document that I want to email to someone. However, I want to make sure that they cannot actually enter the Word document and change it or edit it. I only want them to be able to read the document. Is there a way to do this with Microsoft Office Word 2007? Normally, I would save the Word file as a PDF file. But, in this case, that's not an option. Thanks! (Joseph A. Spadaro (talk) 18:39, 28 March 2011 (UTC))


 * You can password protect it from modification. Go to File > Save As > Tools > General Options > Password. Change the modify password (not the file open password). --Mr.98 (talk) 19:49, 28 March 2011 (UTC)


 * However, that doesn't stop them pasting the contents into a new document and editing that. AndrewWTaylor (talk) 19:51, 28 March 2011 (UTC)


 * Hmmmmmm. I am pretty sure that I have read some Word files that I have tried to open and edit.  And I would get a message that says "this is a read-only file" or something similar.  And thus I would be prohibited from editing or changing the contents of the Word document.  Am I mistaken about that?  Or is there some way for me to make this happen?  Thanks.   (Joseph A. Spadaro (talk) 20:23, 28 March 2011 (UTC))


 * Yes like what Mr.98 said... Nil Einne (talk) 20:26, 28 March 2011 (UTC)


 * It doesn't really stop them editing the file either. There are various tools which can remove or get round any restrictions. Same for PDFs. Suffice to say, if the person you're sending can open/view the file, restrictions such as those should be thought of as at best stopping those without much knowledge and sending a clear message of what you want (perhaps with some legal backing in some countries). Nil Einne (talk) 20:26, 28 March 2011 (UTC)

OK, thanks to all. So, as a follow-up ... let's say that I used Mr. 98's method from above. Now, whenever I myself want to go in and edit the document, I need to have my password to do so? Is that correct? If so, that seems like a big pain in the neck? Or is it just the other person (the recipient of my email) that needs a password to try to edit the file? Thank you! (Joseph A. Spadaro (talk) 21:03, 28 March 2011 (UTC))


 * Well, you could always save a copy of the document, then password-protect one of the copies. You e-mail the protected copy, and keep the unprotected one to work on yourself. --Trovatore (talk) 21:12, 28 March 2011 (UTC)


 * Everybody that uses it would need to enter the password to be able open it as a read-write version. Your best bet is to Version control the document, keep a record of the original version and then use that as the Baseline to compare against. That is to say save a version as 1.0 and then issue it (making that version the baseline), noting that any changes should be made to a saved-copy as a 'draft' version (e.g. version 1.1) that requires sign-off to replace the existing 'baseline' verison. This amount of document control (whilst doing nothing to prevent unauthorised changes/secondary copies etc.) is generally pretty valuable, provided the document is worth the hassle of doing that (given that it does represent a bit). ny156uk (talk) 21:10, 28 March 2011 (UTC)


 * As noted above, doing all of this does not stop someone from cracking the password (using one of the many free online programs), copying the text and pasting it into a new writable Word document, turning off version control, etc... Once you place text in a file, it is possible to edit that text no matter what you do. You have to decide what you want to do. You can try to make it a pain to copy the text if you simply want to stop lazy people from editing it. You can try to track changes if your goal is to see who edited it. -- k a i n a w &trade; 12:20, 29 March 2011 (UTC)
 * See also Analog hole. AndrewWTaylor (talk) 12:52, 29 March 2011 (UTC)


 * The source control option is great if you have the interest and willpower to implement this solution, giving the other viewers of the document their own passwords and usernames and access to your source control server. If not, then the usual way to make sure that someone doesn't make changes to the document &mdash; let's say I were to write a contract and e-mail it to you, and you add some sort of signature and e-mail it back &mdash; is for me to have saved a copy of the document on my own hard disk, and then when I get your copy, I use Word's "Compare" option to compare my copy to yours.  If it sees no changes, then there weren't any changes.  Comet Tuttle (talk) 18:07, 29 March 2011 (UTC)

Do you need to protect against the user editing the file? Would it be sufficient to be able to later verify that you are looking at the same document that you sent. If verification is sufficient then create use a cryptographic hash function to generate a checksum for the original document. You can then later show that your original document matches the original checksum. And altered versions will not match. Taemyr (talk) 18:14, 29 March 2011 (UTC)


 * You can also get a cryptographically encoded timestamp of your document so people are sure not only that you wrote it but that it was issued at a particular time and you didn't sneak in a later one! Dmcq (talk) 10:27, 30 March 2011 (UTC)

iOS SDK Standalone
Is there somewhere I can find the iOS SDK as a standalone?141.211.250.151 (talk) 22:26, 28 March 2011 (UTC)


 * The only official internet site for iOS developer information and tools is: http://developer.apple.com/programs/ios/ - you can navigate around there and see if you find what you are looking for. Nimur (talk) 14:10, 30 March 2011 (UTC)

sfdisk input format
I have a hard drive with three existing primary partitions. I would like to make the fourth partition an extended partition, with five logical partitions inside.

If it was an empty disk, I would run sfdisk <<EOF ,,E ,3900,L ,3900,L ,3900,L ,3900,L ,,L EOF however, this erases the three existing partitions and creates one extended partition that covers the entire disk. How can I tell sfdisk to leave the existing partitions alone and partition the unallocated space only? -- 188.105.131.8 (talk) 23:58, 28 March 2011 (UTC)
 * Is there any reason why you are using sfdisk? fdisk (line-input) and cfdisk (curses) are friendlier. sfdisk looks like it is designed for use in shell-scripts. If you don't want to keep the data on the fourth partition, delete it, and then create an extended partition in its place. If you want to keep the data in the fourth partition, then gparted might be able to convert a primary partition into a logical partition. CS Miller (talk) 18:25, 29 March 2011 (UTC)
 * Yes, there is a reason why I am using sfdisk - I want to use it in a shell script. There is no fourth partition - three primary partitions are defined, the space behind them is unallocated. That's where the sfdisk should create an extended partition (,,E), and fill this extended partition with five logical partitions (4 times ,3900,L and ,,L). -- 188.105.131.8 (talk) 21:19, 30 March 2011 (UTC)