Wikipedia:Reference desk/Archives/Computing/2009 June 29

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Computing desk
< June 28 << May | June | Jul >> June 30 >
Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.


June 29[edit]

vista webpage[edit]

hello is there a webpage that looks like windows vista or xp is there a flash game for psp like vista —Preceding unsigned comment added by Bubbafrogs (talkcontribs) 01:06, 29 June 2009 (UTC)

I do not understand your question. Adding some punctuation might help. -- Tcncv (talk) 01:26, 29 June 2009 (UTC)
You can take a screenshot, upload it to somewhere like imageshack, and view it in a browser - that would make a "webpage that looks like Vista or XP". But there's no need to upload anything, there are plenty of images of Vista/XP desktops that people have uploaded to various forums. Astronaut (talk) 01:58, 29 June 2009 (UTC)

Vista desktops[edit]

Answering the above question led me to see several Windows Vista/XP desktops which appeared to have a Mac OsX-like docking bar (see this guy's desktop for an example). Where can I get that kind of docking bar utility from? Astronaut (talk) 02:04, 29 June 2009 (UTC)

I believe the one in the image is RocketDock. :-) There are other ones available including ObjectDock--Xp54321 (Hello!Contribs) 20:06, 29 June 2009 (UTC)
Another option that I use is Gizmos. The toolbar is highly customizable and can launch stuff besides programs (such as Webpages, custom scripts you write). It also comes with some other cool features such as Virtual Drives and a color coded text editor for writing in C, C++, and other stuff I don't really use such as databases —Preceding unsigned comment added by 24.171.145.63 (talk) 05:46, 29 June 2009 (UTC)

CPUs[edit]

What is the fastest commercial CPU currently on the market? --128.12.77.85 (talk) 04:58, 29 June 2009 (UTC)

Commercially I'm going to guess *probably* the Intel Core i7 975 3.33Ghz Extreme Edition, but I'll happily be proved wrong! ZX81 talk 06:51, 29 June 2009 (UTC)
for x86.64 [1] - I'm willing to prove you right.
Not quite what you asked, but in May, Fujitsu said one of their SPARC64 prototypes is the fastest CPU, at 128 gigaflops. That same link says Intel's top-of-the-line Nehalem Xeon is at 76 gigaflops. Tempshill (talk) 06:49, 29 June 2009 (UTC)
At the same time IBM's POWER range is rated at the highest MHz/GHz commercially available ~5GHz, whilst NEC's SX9 is the fastest vector processor at ~100Gflops. It looks like every company has the fasters by some measure (except ARM)83.100.250.79 (talk) 12:40, 29 June 2009 (UTC)
A related question that should be asked is "What is the fastest motherboard on the market?" Placing a fast CPU on a slow motherboard will kill most of the benefit of the fast CPU. -- kainaw 13:53, 29 June 2009 (UTC)

Internet Radio Recorder[edit]

There used to be a program in Ubuntu that let you record internet radio. Do you know of any for Windows Vista, or should I just stick to a program that records my computers audio output? 24.171.145.63 (talk) 05:46, 29 June 2009 (UTC)

Orbit Downloader records internet radio I believe and it comes with browser plug-ins that introduce context menus that make downloading a snap. They have a tutorial here. -ankØku- (talk) 19:59, 29 June 2009 (UTC)

Who uses Java servlets?[edit]

I'm having a hard time finding any well-known companies that use Java servlets or JSPs. I'm sure Sun and IBM do, but are they're developers of the technology. Most of the sites I see use PHP, Perl, and ASP/ASP.NET. Can any one give me some examples? Come to think of it, I'm having a hard time thinking of many examples of applets out there! Most of the RIAs nowadays seem to be in Flash or AJAX.--Dfnggcb (talk) 08:26, 29 June 2009 (UTC)

There aren't many around because so many end-users have been warned to turn off Java support in their browser for security reasons that big-name web sites don't want to touch Java if they can possibly avoid it because it's a tech-support nightmare. For small niche sites, you have a choice between Java and JavaScript - but Java can't do much that JavaScript can't do unless you use a "signed" server - that process is painful and incurs a significant annual fee to the web site owner. There are a bunch of cool things I wanted to do on my web site - but in the end, I'm not paying the signing fees - and if I have to restrict myself to the Java subset that can run unsigned - then I might as well just use JavaScript, PHP, Flash(Yuk!), etc. SteveBaker (talk) 14:06, 29 June 2009 (UTC)
What's wrong with Flash? I use Flash on most of my sites. As you just said, Java is hard to use. And I doubt you could make a Java applet that looks like this: [2]. That's not even taking into account problems with debugging across platforms.--Dfnggcb (talk) 22:01, 29 June 2009 (UTC)
SteveBaker, you are thinking of applets (which run on the browser) not servlets (which run on the server). A lot of companies use servlets or JSPs, though not all directly. We use struts/stxx for example, which is implemented as a servlet. I would go as far as saying almost all companies with websites running on Java will use servlets - the alternatives are either very low level (code using sockets) or niche like restlets. That is all companies using Weblogic, Websphere, Tomcat, Glassfish, JBOSS, and many more. -- Q Chris (talk) 14:22, 29 June 2009 (UTC)
To find some try googling for those advertising for "Java Web Developer", a couple I found were Barclays, General Motors, and British Airways. Of course I don't know if these are for niche sites or intranet only. -- Q Chris (talk) 14:36, 29 June 2009 (UTC)
Yeah, SteveBaker's answer is way, way off here. There are important differences between server side and client side java. Server side java is very very widely deployed, but you can't necessarily tell who is using them just from seeing the website. Friday (talk) 14:41, 29 June 2009 (UTC)
Thanks for the replies. I ended up using Career Builder to search for the words J2EE and then servlet to find companies looking for servlet developers. It turns out that there are many well-known companies using them.--Dfnggcb (talk) 18:56, 29 June 2009 (UTC)
There's also Tomcat (software)'s list of companies using their popular JSP server: [3]. Indeterminate (talk) 20:58, 30 June 2009 (UTC)

Madden 07 Xbox 360 Controls[edit]

I got this game at the weekend at a bargain price but it came with no instructions. Whilst I can get the controls from the in-game menu does anybody know of any resource that has a full list of the controls so that I can print them out for quicker reference? A pdf of the booklet, or anything like that would be great. I couldn't find anything when I looked. Is there a site that's dedicated to game-controls or online (free) PDFs of game-booklets? (oh and I know the game is ancient but as a non NFL follower I just thought i'd give the game a go as I used to enjoy the old Madden games back in the day). 194.221.133.226 (talk) 09:26, 29 June 2009 (UTC)

Found it (http://www.gamesegment.com/XBOX360/instructions.cfm/id/9110375) ny156uk (talk) 15:58, 29 June 2009 (UTC)
Good find! I wasn't turning up anything. Tempshill (talk) 16:02, 29 June 2009 (UTC)

My Computer is gone[edit]

On windows vista I accidentally selected "My Computer" or whatever it's called now and deleted it. I can't find it in the recycle bin, and I can't find any options to bring it back. How do I get it back? Thanks —Preceding unsigned comment added by 82.43.91.128 (talk) 11:33, 29 June 2009 (UTC)

I cannot be deleted because it doesn't exist. It is just a convenience link. By "deleting", you just removed the convenience. To replace it, click the Start button. You will see an entry called "Computer". Right-click on it and select "Show on desktop". -- kainaw 11:54, 29 June 2009 (UTC)
I don't have "computer" on the start menu, all I have is shut down, run, help and support, search, settings, documents, programs, windows update, default programs. —Preceding unsigned comment added by 82.43.91.128 (talk) 16:23, 29 June 2009 (UTC)
If you right click on an empty area of the 'taskbar' - that's the bar at the bottom where the running programs and open files appear - you should see a dialog box. Press properties, then 'start menu', here you might need to change between different formats eg classic etc. Then select 'customise', then 'advanced' - this should get you to a box that shows a list of "start menu items" - from this list check the box for "display My Computer" or equivalent. Then press apply/ok. This should make the MyComputer icon appear when you press the 'Start' button. You can then get the link as described above. (Note this is for XP, though Vista should be very similar or identical method).
Once you've got the link you can go back and change 'start menu' to the way it was. Whilst you are there you might as well take some time to customise the start menu to show all the things you want - It's often useful, and you'll get familiar with the method. Hope this works for you.83.100.250.79 (talk) 17:12, 29 June 2009 (UTC)
That worked perfectly! Thank you :) —Preceding unsigned comment added by 82.43.91.128 (talk) 17:31, 29 June 2009 (UTC)
Spoke too soon, it only works if I say on vista start menu, but as soon as I switch back to classic start menu My Computer icon is gone again —Preceding unsigned comment added by 82.43.91.128 (talk) 17:34, 29 June 2009 (UTC)
Mmh, once you've got the icon on the desktop, right click on it, and select "create shortcut" - that should make a shortcut copy, probably named "shortcut to My Computer" on the desktop. Then you can switch back to classic view. The shortcut icon will definately not dissapear (I hope), then all you have to do is rename the shortcut icon to "My Computer" or whatever you want (another right click) - that should fix it.83.100.250.79 (talk) 19:29, 29 June 2009 (UTC)
Thats worked, thanks. The icon is slightly different now, it's got a shortcut arrow on it. But it works so I'm happy :) —Preceding unsigned comment added by 82.43.91.128 (talk) 20:07, 29 June 2009 (UTC)
I don't know how to get rid of that arrow - if you find out - let me know :)
83.100.250.79 (talk) 20:42, 29 June 2009 (UTC)
Just had the chance to look at Vista. Try this: Right-click on the desktop. Choose personalize. Do you have a Change Desktop Icons on the left menu? If so, click it. The possible desktop icons will appear and you can place a check next to those that you want to show up on your desktop. -- kainaw 21:03, 29 June 2009 (UTC)
THANK YOU :D Worked perfectly :) —Preceding unsigned comment added by 82.43.91.128 (talk) 21:59, 29 June 2009 (UTC)

IBM POWER6 Decimal floating point[edit]

According to POWER6 the processor has a decimal floating point unit. Outside the azure confines of IBM does this make any sense - I mean does anything actually use decimal floating point, and why? Thanks.83.100.250.79 (talk) 13:25, 29 June 2009 (UTC)

Well, one of the things IBM made it's money on is backwards compatibility. The POWER6 is an enhanced POWER5 which is an enhanced...POWER. The POWER uses the 801 architecture - which is backwards compatible with the IBM System/370 - which is compatible with the 360...which was designed to emulate the 1400 - which was around in 1964! There is quite a lot of software that was written in the late 1960's and early 1970's on 'lumbering giants' that people still run. Very often, they don't even own the source code anymore - or the binaries have been patched so many times that the sources are no longer reliable. (This is one reason why concern over the Millenium Bug was such a big deal.) Being able to buy machines that still run that old junk is evidently still a good business model. Binary Coded Decimal arithmetic is still popular in financial processing because accounting systems have to be able to guarantee accuracy down to the last penny - even in calculations that might require millions or even billions of dollars/pounds/euro's. In a modern programming language, there are much better ways to deal with that - but so much of that old stuff is written in Cobol - so there you go. SteveBaker (talk) 13:49, 29 June 2009 (UTC)
I suppose they can convert the BCD to decimal floating point and use the floating point units then.
I'm still trying to come to terms with mending the binaries and not the source . ouch . Thanks for your answer - made me feel young (that doesn't happen so often nowadays!)83.100.250.79 (talk) 14:02, 29 June 2009 (UTC)
At SteveBaker: Surely the POWER6 cannot be compatible with the S/370... My understanding is that the POWER6 a new implementation of the Power ISA (formerly PowerPC); the POWER5 was an enhanced POWER4, itself a new implementation of the PowerPC architecture; the POWER1 was an implementation of the POWER architecture, which was based on ideas from the IBM 801, a RISC machine instead of a CISC machine like the S/370. The only microprocessor from IBM that has decimal floating-point and is compatible with the S/370 that I know is the z10, which is used in the IBM System z10 mainframe. Rilak (talk) 11:53, 2 July 2009 (UTC)
Decimal floating point isn't just binary floating point with the base changed, it's more like a collection of numeric operations that are useful in finance. I don't think it's dying. A new standard came out just last year (IEEE 754r), and was incorporated into the C++ standard by a technical report. Intel published a high-speed software implementation of it for x86. Sure, you can use a fixed-point library, but every fixed-point library is different. How many digits should it allow after the decimal point? Are you sure? Can it calculate 1.0825n to within 0.5 ulp? The point of standardizing decimal floating point is the same as the point of standardizing anything else: it justifies putting extra effort into well-tested high-quality implementations, including hardware implementations for people who need the speed.
Binary floating point is unacceptable for financial calculations even if they involve small amounts of money. Try running the following program:
   #include <stdio.h>
   
   volatile float f = 0;  /* force rounding to single precision at each step */
   
   int main() {
       int i;
       for (i = 0; i < 20000; ++i)
           f += 0.01;
       printf("%f\n", f);
       return 0;
   }
My machine prints 199.969376. That's off by 3¢ after only 20,000 additions of amounts under $200. -- BenRG (talk) 15:52, 29 June 2009 (UTC)
Yes. Of course you could make cents (or hundreths of centswhy) equivalent to 1 instead of counting in dollars - which solves that problem. Maybe I should email my CV to IBM :) 83.100.250.79 (talk) 16:11, 29 June 2009 (UTC)
More seriously, this brings me back to my original question which was why "decimal floats" - at my limited level of understanding it seems to me that only the mantissa is useful - eg if I have 10googlegooglebucks and spend 1 dollar then in a float representation it seems likely that the 1 dollar won't even register on the float representation. Wouldn't a fixed point decimal representation make much more sense?83.100.250.79 (talk) 16:28, 29 June 2009 (UTC)
It was precisely that type of "only 3 cents" fraction that was syphoned into another account to make the programmer very rich, in a famous early computer fraud case. If the program cannot be out by anything, nobody can steal the "mistake" and nobody has to account for it (either in the books or in a court). - KoolerStill (talk) 20:42, 29 June 2009 (UTC)
Fixed point is like floating point with a constant exponent. The trouble is what exponent to choose. Some financial calculations are required by law to be done in mills and I think some are done in tenths of mills. You also have to work with multiple currencies and I don't know how the conversions are specified to work. Most likely a single program-global exponent wouldn't be good enough. Your other options are (a) work with bare integers and use variable names and comments to distinguish the formats, (b) distinguish them in the type system (if your language has a type system) or (c) distinguish them dynamically by bundling format specifiers with the numbers. Option (a) is horribly bug-prone. Option (b) is probably not flexible enough in general. Option (c) is decimal floating point by a different name. With any numeric format of bounded size you are going to have cases where the output isn't exactly representable; $1 googol + $1 is one such case for floating point, but in a fixed-width fixed-point format $1 googol wouldn't have been representable to begin with. The computation that produced it might even have wrapped around, which would be even worse. IEEE 754 provides inexact-result and overflow exceptions that will catch these cases. A well-written financial library would presumably check these flags and redo the calculation in arbitrary precision where necessary. I suppose I should mention at some point that I've never written any financial software... -- BenRG (talk) 21:04, 29 June 2009 (UTC)
Thanks, my example about 1google$ was meant roughly as an example.. (obviously) though from my reading of Decimal floating point it looks like the format includes expressions for number that have an accuracy of less than 1 integer: eg ~33 decimal places and an exponent that has more than 12bits (14 I think) that's > 2^4000 or ~>10^1200 --- way more than 33 decimal - It looks like massive overkill - the exponent would never be used ??
These number formats are just for accounting (not engineering) ??
I suppose the solution is as you describe - make it easier on the programmers (and harder on the chip designers) - it would/does minimise possible errors if there is only really a single (hardware) implementation of the numbers, rather than 100s of program specific implementations. I suppose that's the real answer then. Thanks.
Still I didn't think financial calculations would ever be extensive enough to require hardware acceleration - even if I had 2billion employees (literally) it wouldn't take a modern desktop PC long to calculate their end of week interest, wages, and taxes (10 seconds?) Maybe someone could shed some light on this, and answer my additional supplementery questions?83.100.250.79 (talk) 22:19, 29 June 2009 (UTC)

Windows graphing program for excel spreadsheets[edit]

We have data in excel spreadsheets. We want graphs that excel is not capable of producing. What is available to produce good graphics from the excel data? -- kainaw 13:55, 29 June 2009 (UTC)

Did you want a stand alone visualisation program? It's easy to output as CSV and then import into your favorite programming language (assuming it has graphics support for the output) - using that method gives you as much flexibility as you could wish for the graphs, and is probably quicker (and cheaper) than finding a special program.83.100.250.79 (talk) 14:12, 29 June 2009 (UTC)
Sigmaplot comes with a 30 day trial, which you'd expect before forking out around $800. Probably more affordable is Dplot, an Excel add-on for $60. This too comes with a free trial.- KoolerStill (talk) 14:20, 29 June 2009 (UTC)
Thanks, we're debating Sigma and Delta. Perhaps using the evaluations will let the users decide which one they like. The problem with evaluations is that they assume the users know how to use the programs. In reality, you lose most of the evaluation time just trying to make the program function properly. -- kainaw 14:47, 29 June 2009 (UTC)
Crystal Reports is excellent at graphs, but run it stand-alone. It's horrendously slow in a multi-user datawarehouse or similar environment. Sandman30s (talk) 22:30, 29 June 2009 (UTC)
There are graphing tools in Adobe Illustrator that will accept data from Excel. If you click with one of the graphing tools, a spreadsheet will pop up where you can paste data. After the graph is drawn, you can rotate it in 3D space, add shadows, reflections, and so on.--WinRAR anodeeven (talk) 22:48, 29 June 2009 (UTC)

Replacing PS3 HDD... clone first?[edit]

I want to install a larger hard drive into my PS3 (it makes a great media hub. Game? meh.) How can I copy all my game saves and DLC to my new drive? Some game saves (like Rock Band) don't allow copying to a memory stick. --70.167.58.6 (talk) 15:43, 29 June 2009 (UTC)

You have to use the backup utility to an external harddrive. You can't just copy the files. -- kainaw 15:50, 29 June 2009 (UTC)

Solaris 10 and open Solaris[edit]

I was going to try using solaris, but Sun gave me two options - I don't need to see the source code, but I can't distinguish between the two otherwise from the description on Sun's website. Can anyone describe what the difference is? Thanks83.100.250.79 (talk) 20:09, 29 June 2009 (UTC)

Open Solaris is free to download and use. But you can't update it. If you pay for Solaris, then you can download updates. In either case, keep in mind that Sun will be releasing version 11 in mid 2010. So, you might be better off waiting a year if you want to get Solaris.--WinRAR anodeeven (talk) —Preceding undated comment added 21:58, 29 June 2009 (UTC).
OpenSolaris is free and you can get updates for free. Regular Solaris is free, and security updates are free, but any patches that add additional features require a service contract. Regular Solaris also is commercially supported by ISVs, so the software developers of any programs you may be specially running on Solaris will officially support your software - they may laugh at you if you tell them you're running on OpenSolaris, even if the program works as advertised. Solaris is better suited for commercial environments, and OpenSolaris is better for hobbyists. One is not necessarily better than the other. Alex (talk) 12:45, 2 July 2009 (UTC)
Thanks, that's what I sort of had guessed. Apart from the updates - are there any major differences between the two distributions that are obvious and important - such as compatability issues (general use) - also are both ok with the javabeans ide + c/fortran development kit (on experience) - or would one be a better match. (I fall into the amateur category, not major server vendor , obviously) 83.100.250.79 (talk) 19:20, 2 July 2009 (UTC)

Ubuntu - still free after 18 months?[edit]

From the Ubuntu website "Ubuntu is and always will be free of charge." But elsewhere it says: ""....with the benefit of free updates for 18 months." What happens after the 18 months are up? 78.144.242.64 (talk) 20:42, 29 June 2009 (UTC)

The ordinary releases are supported for 18 months, after which time Canonical stop making updates available for it. The LTS ones are updated for 3 years (5 for servers). All that happens after these times is that they don't send you any more updates. Almost everyone will, before those periods are up, update to a later version. Ubuntu also contains a distribution-update program which keeps your install at the latest version (unless you tell it not to). 87.115.103.157 (talk) 20:53, 29 June 2009 (UTC)
(In case somebody doesn't know Ubuntu aims to make a new release every 6 months.) --194.197.235.36 (talk) 21:16, 29 June 2009 (UTC)

The information could be worded less ambiguously. Does it mean "we give you free updates for 18 months, but after that you've got to pay for them!" or does it mean "We do updates for 18 months, and then don't do any more. All the updates are free."? 92.27.159.22 (talk) 23:15, 29 June 2009 (UTC)

The latter. It should be made more clear, but it does say it is and always will be free at the top, so that gives you a bit of a hint. Thanks, gENIUS101 23:59, 29 June 2009 (UTC)
Just to be clear you can keep using any version of Ubuntu free of charge for as long as you want. After a certain time you will no longer receive updates and security releases. It is probably in your interest to upgrade but you are perfectly entitled to stick with the old version. -- Q Chris (talk) 08:17, 30 June 2009 (UTC)

Windows or Linux - which is technically better?[edit]