Wikipedia:Reference desk/Archives/Computing/2013 March 21

= March 21 =

How much can Javascript and other types of scripts do?
For example, can it reveal my true IP address, physical address, mu username, the last site I have visited, and where I download my files to?--Inspector (talk) 02:52, 21 March 2013 (UTC)


 * You're invalidly conflating Javascript, which is a programming language that happens to (usually) be interpreted, with the security model of its script host - often your web browser. Technically, Javascript is a Turing complete language.  Roughly speaking, that means that it can do anything that any other programming language can do.  In practice, it is usually sandboxed.  For a quick overview of the security model (sandboxing) of, say, Firefox, read the Firefox promotional literature on security or the much more thorough and technical Mozilla/Firefox/FirefoxOS Security model for developers, and the Document Object Model.  Nimur (talk) 03:25, 21 March 2013 (UTC)
 * Great answer for a question that should really be at the computing RD. Vespine (talk) 03:56, 21 March 2013 (UTC)
 * And so we can set constraints to some actions just like what we do to other programs? Actually, what pieces of information are available for reading and sending for a javascript or other scripts while running on my computer?--Inspector (talk) 06:58, 21 March 2013 (UTC)
 * For the "enthusiast" - MozillaZine Security Policies wiki
 * For the "developer" - Configurable Security Policies
 * Of course, these only apply to Mozilla products like Firefox and Thunderbird; but it will help get you into the correct frame-of-mind to pursue this investigation on other web-browsers and other sandboxed programming environments. Nimur (talk) 15:28, 21 March 2013 (UTC)

Mac Powerbook vs Laptop w/ Windows 7
I had a 2005 G4 Mac Powerbook with which I was quite happy until I found it would not support Netflix silverlight or run Flash very well or download with RealPlayer. I got a Gateway Windows 7 laptop which is the only reliable PC I have ever owned. But it needs replacing, and I have never been happy with the picture, which unlike the Mac is dark and cannot be seen at an angle, or with the sound, for which I had to buy external speakers in order to hear half of what's on Youtube.

I intend to buy either a new Mac or PC laptop. It will have to be a 17" screen with HD and a bright clear picture visible at an angle. It will probably be my only source for "TV" watching, and will mostly otherwise be used for browsing and with Microsoft Word.  I don't want to waste, but am not afraid of spending money.  Under NO circumsatnces will I get Windows 8, with which I am unfortunately familiar.


 * 1) What should I be looking for to give the highest picture and sound quality (and volume in the latter)?
 * 2) Is there any reason to prefer a Mac over a PC running Windows 7 or vice versa for program compatibility, especially Real Player, Adobe, Netflix, VLC, and Real Player?
 * 3) Can I get a laptop of any sort that is region free on dvd/blueray?  I watch a lot of Spanish films.

I'd appreciate any advice or links to relevant reviews or resources. Thanks! μηδείς (talk) 12:34, 21 March 2013 (UTC)


 * 1. For TV with the "highest picture and sound quality" you will struggle to beat a proper TV (in a domestic setting). Modern HD flat screen TVs are very good - or at least my 37" Panasonic is very good - especially when linked with a HD source such as a bluray player or the HD offering from your cable/satellite provider.  You can also watch it at a comfortable distance in your living room, rather than huddled over the tiny 17" screen of a laptop; I don't understand why so many people think watching TV on a laptop is a good idea.  However, from what I can tell, the screen on the higher end Macs is superior to that on many PC laptops, though my Dell laptop screen is pretty good too.
 * 2. A PC running Win7 is compatible with all the software you mention, but you will get better results with more top-end hardware rather than a bargin basement $399 PC. As for Macs, Apple have a well known dislike for Adobe Flash, but maybe that is only on iPhone/iPad.  I don't know about Mac's compatibility with t he other software you mention.
 * 3. You used to be able to get your PC's DVD drive switched into region-free. However the spoilsports who watch over that kind of thing (RIAA?) clamped down.  Now, you get to change the region a few times before the hardware gets locked to the last used region - 1 for USA or 2 for Europe.  Bluray does have region coding - A for USA or B for Europe - but much commercial content is released region-free.  As for a region-free bluray player, my 'under the TV' box can be made region free, but I haven't heard of it being possible on a built in player for a PC or Mac.
 * Astronaut (talk) 17:25, 21 March 2013 (UTC)
 * Thanks, but I extremely unlikely to lug a flat screen onto the train. Since I am about 95% likely to order from Amazon, I really do need advice on how to identify a better picture and sound quality based on specs, since I won't have the computer before me to compare.
 * This is the sort of purchase where I like to check out the options as a big-box store such as Best Buy. They won't have as great of a selection, but you should be able to see what the displays on most common models of laptops are, even if you order one online from the same line with different specs. Also, if you find one you like, I know that Best Buy now price matches Amazon. As long as you completely ignore everything any salesperson says it isn't that terrible of a place. :-) 38.111.64.107 (talk) 18:58, 21 March 2013 (UTC)


 * Unfortunately requiring a decent display is going to seriously constrain your options, since laptop displays these days really suck for the most part. For wide viewing angles you need an IPS or at least a VA panel, so look for that in the specs. Most laptops have TN panels, which is almost certainly the type of the Gateway screen you didn't like. I just searched Amazon for 17" laptops with "ips" and "va" as keywords and found absolutely nothing, so good luck.
 * I don't know the current situation regarding region-free drive firmware, but VLC will play DVD and Blu-Ray discs from all regions on any drive as far as I know. -- BenRG (talk) 18:06, 21 March 2013 (UTC)


 * I see Sony VAIO has the IPS display, but the model has other drawbacks I don't like. μηδείς (talk) 18:49, 21 March 2013 (UTC)

Is it time for a Nvidia Volta page?
Is the Nvidia Volta just vaporware trivia, or does it yet rise to the level of deserving its own page?

I've stuck what few details I know over at Nvidia Tesla for now. Hcobb (talk) 15:43, 21 March 2013 (UTC)

Windows 8 upgrade - can it be used for a clean install if you have original product key etc
Hi, my partner's dad has two PCs - a desktop with Windows Vista, and a laptop with Windows 7 (both are the Home Premium edition). He didn't like the change from XP to Vista, but he really likes the look'n'feel of his new Windows Phone, so I've been thinking about recommending he upgrades his PCs to Windows 8.

I can find the upgrade version of Win 8 Pro for under £50 - however his Vista machine currently runs like a dog, so I'd prefer to do a clean install. If he has the original product key for his old OS, can you do a clean install of the upgrade version, or does it need to install over the top?

In case there's more than one type of upgrade, the one I'm thinking about is /.

Thanks, d avid p rior  t/c 19:06, 21 March 2013 (UTC)


 * You won't need your original product key for your old OS. You'll only need the product key for Windows 8.  When you install Windows 8, there will be a screen asking you to choose what to keep.  Select "Just personal files" (or "Nothing" if you have a back up of all your files). Either option will give you a clean install.  Your old Windows directory will be saved and renamed "Windows.old".  Here's an article that touches up the subject.  I'll see if I can find a better one.  A Quest For Knowledge (talk) 20:40, 23 March 2013 (UTC)

Cookies
How do I "enable" Cookies on my iPad please?85.211.138.47 (talk) 19:42, 21 March 2013 (UTC)
 * Hi, I don't have any real-life experience with the iPad, but this seems to explain how to set it (in the section "To set whether Safari accepts cookies").   d avid p rior  t/c 19:46, 21 March 2013 (UTC)

Wow, that was quick; many thanks.85.211.138.47 (talk) 20:27, 21 March 2013 (UTC)

'The sender of this message has asked to be notified when you read this message.
When reading an email through Thunderbird, I get the message above. However, when I read the same message through gmail I do not get it. Does Gmail reject or confirm such requests automatically? OsmanRF34 (talk)


 * This feature is called "read receipts", and it's only available for paid Google Apps accounts, not on free personal gmail. -- Finlay McWalterჷTalk 20:39, 21 March 2013 (UTC)


 * According to, read receipts in gmail not available on personal accounts. What gmail does for accounts where it is enabled is up to the administrator.  For accounts that don't support it, it doesn't say, but I assume the read request is just ignored.  RudolfRed (talk) 20:41, 21 March 2013 (UTC)


 * OK, but it's the sender who has to have a paid Gmail account, not poor me, the recipient with the personal Gmail account, right? I cannot ask for a read receipt, but I can send them when requested. (So I understood it). So, how does Gmail deal when it gets a request for a "read receipt." I know Google is not very eager in respecting privacy, so I won't be too sure that it just ignores it. OsmanRF34 (talk) 20:53, 21 March 2013 (UTC)


 * From the way I read the link in my previous reply, you cannot respond to receipt requests if you don't have one of the paid gmail accounts. Also, it only works through IMAP, not via POP or other clients.  RudolfRed (talk) 22:49, 21 March 2013 (UTC)


 * RudolfRed: My understanding is that read receipt requests and responses are typically handled by e-mail clients, not by e-mail servers. If you use a POP client to download your e-mail, the linked document only says the Gmail system (Google Apps for Business, Education, and Government) doesn't send a response back to the sender. Your POP client is still free to interpret the read receipt request and send a response.
 * The document does say that the Gmail system could automatically send a read receipt when a message is opened via IMAP, if the administrator has enabled that option. This kind of feature isn't typically handled by the e-mail server, but I can see how it might make sense for business accounts, so senders can track if messages are read. Because that's an unusual server feature, the document confirms the Gmail system does not send a receipt when you access messages by POP to avoid any doubt. --Bavi H (talk) 02:37, 22 March 2013 (UTC)
 * I would advise not setting the option to automatically respond. As far as spammers are concerned it means it is a confirmed email address and so more worthwhile to send spam to. The feature was devised long ago by some committee before spammers came on the scene. Dmcq (talk) 22:29, 23 March 2013 (UTC)

Does Intel 4000 GPU support OpenCL 1.1?
I know the 4000 is pretty wimpy. I have software that requires OpenCL 1.1 to use 'GPU acceleration'. Does Intel 4000 GPU support OpenCL 1.1? --157.254.210.11 (talk) 21:44, 21 March 2013 (UTC)
 * Yes, according to OpenCL. Also here's some benchmark results for its OpenCL performance .   d avid p rior  t/c 22:35, 21 March 2013 (UTC)