Wikipedia:Reference desk/Archives/Computing/2007 June 26

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June 26[edit]

Video Games Consoles and Storage[edit]

I've been thinking about the storage provided for consoles recently (in particular for the Xbox 360) and I've encountered a couple of things that don't make sense.

Firstly, why is the capacity of the hard drives so low? My Xbox has a 20GB HDD, if I wanted to buy one it would cost about £65, but for the same price I could get a 160GB HDD for a PC which would spin at the same speed and use SATA. So why are the hard drives so small when they could be much larger for the same price, is there something specific about the Xbox HDD that makes it more expensive or is it merely a case of Microsoft trying to take advantage of the fact they're the only people making the HDDs in order to make more money?

Secondly, why are the capacity of memory cards so low? The official Xbox 360 memory card is 64MB but nowadays 1GB USB pens are extremely common and cheap so it's not as if it's not possible to make much larger (in terms of space), while still physically small, storage devices. Do Microsoft not believe there is a need for larger cards? Is there a hardware issue about the possible size of a memory card (or from another POV, is USB deemed too slow a transfer method for saving games?) or is it again a case of Microsoft trying to give a little for a high price since they lack rivals? --Kiltman67 01:31, 26 June 2007 (UTC)

1- Cut costs, also remember that the Xbox is rather old now, my computer is around the same age, and only has an 80GB HDD. 2- Again, you have to remember that memory has come a long way since the 360 was released, it's been nearly two years. But in general, since the bulk of save games are on the console itself, memory cards still don't need to be very large. -- Phoeba WrightOBJECTION! 01:39, 26 June 2007 (UTC)
Can't you plug external USB hard drives into the 360? -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 01:42, 26 June 2007 (UTC)
As far as I know the 360 is designed not to allow you to use a USB hard drive, probably so they can keep a monopology over HDDs. --Kiltman67 03:18, 26 June 2007 (UTC)
It's purely a propriety/marketing strategy thing, there is no reason why there couldn't be a 120GB drive for seemingly the same price, except for the fact that Microsoft then couldn't screw you for the 20GB version. Vespine 04:31, 26 June 2007 (UTC)
The problem is, you are trying to compare two seemingly similar but quite different markets. The PC and 'generic' electronics market thrives on constantly delivering newer, cheaper, better goods to consumers. Most markets do not move nearly as fast, especially when they are wholly proprietary. There are plenty of examples of this in the electronics industry, including Sony, MS, Apple, etc. The examples in other industries are endless. The bottom line is, you don't get rich by lowering prices, and until there is true competition that impacts sales, they will charge whatever they want for as long as they want. --Jmeden2000 17:37, 26 June 2007 (UTC)

Notes replication question[edit]

We have two Notes servers set up temporarily where mail files are replicated between each other. Mail is sent to only one server (say server1), and mail is read on the other server (say server2). The problem is that some messages in the mail file on server1 never end up on the mail file on server2, even when replicated.

How can one force that every message in the mail file on server1 must be replicated/copied to the mail file on server2? Notes replication seems to be stubborn in that it won't reliably do this!

linux[edit]

what the basic linux commands for managing files and what the prerequisite programs during first installation so that it will allow dual booting choice. Lawrete

It would help if you told us what distro you're using, ubuntu can set up dual boot very easily, whereas another distro might give you trouble. As for commands, http://www.linuxcommand.org/ -- Phoeba WrightOBJECTION! 08:03, 26 June 2007 (UTC)
In Fedora Install Windows (making sure you leave some free space for Fedora) then Install Fedora when it comes up with the partitioning menu select use free space. There you now have dual boot computer (Note: This works on just about every main distro(SUSE, Fedora, Ubuntu the lot)) Hope this helps! --Chris g 11:03, 26 June 2007 (UTC)
For any linux distribution (or any Unix too), you're going to know several commands for file manipulation, explained here: List_of_Unix_programs#Files_and_texts. As for dual-boot support, all linux installers will come with a bootloader, something like GNU GRUB. This utility installs a very special program in the boot sectors of your boot disk, and will give you a choice of boot options. Keep in mind, that a windows install writes over the bootloader, so the above suggestion to install windows first, then linux stands. When you install windows, make sure that you leave unpartitioned space for linux. If you do not leave unpartitioned space, you will have to use a tool like PartitionMagic or GNU Parted to resize your windows partition. -- JSBillings 11:48, 26 June 2007 (UTC)

One more thing...[edit]

I've moved your reply up so it's in the same place as the rest of your question (under the heading "A problem with Windows Movie Maker..."). You don't need to create a new heading every time you reply. — Matt Eason (TalkContribs) 16:56, 26 June 2007 (UTC)

Object Oriented Programming(OOP)[edit]

What are the merits and demerits of OOP? —Preceding unsigned comment added by Preethikrish (talkcontribs)

See Object Oriented Programming to start. To be so overly-simplified as to be only partially correct, the key advantage to OOP is reusability. -- (¿ʇɐɥʍ) ʍɐuıɐʞ 16:05, 26 June 2007 (UTC)

I am not the OP but all I know is object-oriented. What else is there?

There are other programming paradigms besides OOP. The most common ones are procedural programming, functional programming, and logic programming. See the programming paradigm article for more examples. --64.236.170.228 16:04, 3 July 2007 (UTC)

NAT Help please[edit]

Hey guys, i have some problems with my starcraft computer game and I found this reply to the same question on some forum: "I fixed the problem, turned NAT off in the modem and had my router assign ip address to my computers." What does this mean? Can someone give me instructions please. 69.156.52.236 17:51, 26 June 2007 (UTC)

NAT is Network address translation. "router assign ip address" sounds like using DHCP, that is, your computer(s) don't have fixed ip address(es) but are assigned these numbers dynamically by your router.
Depending on your router you can probably login as admin using your browser (probably by something like http://192.168.0.1) where hopefully you'll find a menue where you can switch dhcp on or off. Before changing anything, be sure to have your id and password for your internet provider written down somewhere as there is a chance you might screw up the router so you need to reset factory defaults and reconfigure your internet access. 84.160.223.83 19:15, 26 June 2007 (UTC)
I think what you want to do is port forward the StarCraft ports to your computer's private IP. Splintercellguy 23:17, 26 June 2007 (UTC)

Supercomputers & Protein Folding[edit]

I was wondering how long it would take a teraflop/second computer to simulate 100 microseconds of protein folding.

According to IBM:

The computational effort required to study protein folding is enormous. Using crude workload estimates for 
a petaflop/second capacity machine leads to an estimate of three years to simulate 100 microseconds.

I know that a petaflop is 1,000 times faster than a teraflop, does that mean I simply have to multiply 3 years by a thousand? That doesn't sound right and 3000 years seems like an awfully long time.

- Pyro19 18:38, 26 June 2007 (UTC)

You've got the math right. Just change the scale if you want to make it easier to comprehend. If the job on a one petaflop/s system takes 3 seconds, then on a one teraflop/s system it would take 3000 seconds. -- JSBillings 18:54, 26 June 2007 (UTC)
I found this article which says that scientists were able to simulate 800 nanoseconds of protein folding in two months on a Cray T3E. That supercomputer operated at about a teraflop/second.
To figure out how long the T3E would have taken to calculate 100 microseconds I tried this:
60 (days) / 800ns = .075
0.75 * 100,000ns = 7500
7500 / 365 = 20.5
If the math is right, and I have no idea whether it is, it would take about 20 years on the T3E. Is that right?
- Pyro19 19:29, 26 June 2007 (UTC)
Because of Moore's Law, there are many such computations that will finish sooner if you insert into these steps:
Step 1. Buy fastest machine on market
Step 2. Start your computation
the following optimization:
Step 0. Wait 20 years
Strange but true. --TotoBaggins 19:19, 26 June 2007 (UTC)
Another way you can do it is by buying the fastest machine on the market, start a specific problem, and when you're done buy a new machine to begin that next set of problems. That way you progress faster and faster each time. Probably expensive though. - Pyro19 19:29, 26 June 2007 (UTC)
A good programmer can write code that will checkpoint their data, so they can stop a certain calculation and start it up on a faster computer, just make sure you use a portable data format like HDF5. -- JSBillings 11:58, 27 June 2007 (UTC)
Be careful with these calculations; the speedup often isn't what you would expect. See Amdahl's law for the details. --cesarb 00:42, 27 June 2007 (UTC)


The actual time is less. From Folding@Home:

In fact, it takes about a day to simulate a nanosecond (1/1,000,000,000 of a second). Unfortunately, proteins fold on the tens of microsecond timescale (10,000 nanoseconds). Thus, it would take 10,000 CPU days to simulate folding -- i.e. it would take 30 CPU years! That's a long time to wait for one result!

http://folding.stanford.edu/science.html

--h2g2bob (talk) 04:22, 27 June 2007 (UTC)

MS Word[edit]

I worked on a very long document today (an appellate brief) and wanted to insert page numbers in two sections plus a cover page like this: cover page, section one page number in small letters (i, ii, iii, iv . . . ), and section two with regular number (1, 2, 3 . . . ). I followed the instruction provided in the help, but it didn’t work. Question: In WordPerfect, the program allows me to read codes so I can understand why program is behaving the way it is behaving. When I worked on the web site, using the html language section, I could see the codes in there so I have some idea what is going on. Does MS Word have anything like that available? In the other word, how do I get under the hood to investigate the problem?Chailai 21:07, 26 June 2007 (UTC)

Can't help you with the first problem, though it dose sound pretty rudimentary and I've found the help files to be pretty good in general, have you tried to look up indexing tutorials or something in Google? Maybe just try again, or start a test document from scratch? I've seen large documents become strangely corrupt where something won't work, but you simply copy and paste it into a new blank document and it is all fine. As to "how do you get under the hood of a Microsoft application?" short of actually being a Microsoft employee, and probably quite a senior one, there is no way, Microsoft is closed source. Vespine 22:30, 26 June 2007 (UTC)
A right click on code fields gives options including reveal codes. Is that what you're looking for? Donald Hosek 22:58, 26 June 2007 (UTC)
As for actually fixing your problem, if you want a suggestion for that, make sure that you have a section break between the small letters section and then numeral section pagination. Then, if you are paginating in the header or footer, make sure the "same as previous" button in the header/footer toolbar is turned off in the first header or footer in the numeral section. I was actually doing a similar thing with a formal report last night! –Pakman044 23:35, 26 June 2007 (UTC)
I did the section break, page break, and all that. I firmly believe the file is corrupted.Chailai 16:00, 27 June 2007 (UTC)
That's one advantage of OpenDocument; once you know it's in fact a JAR file, you can easily see (and edit) the document internal structure. --cesarb 00:36, 27 June 2007 (UTC)

Thanks you very much for your suggestions. The document is 50-page long, and I ended up breaking it into three documents. As I understand it, every time we press a keyboard, it writes something to the file, and if I can’t see what I write, it is like working in the dark. I will look into the OpenDocument and be sure to report back. Thanks again for your help.

To response to Donald Hosek, yes, the reveal codes are what I’m looking for. Chailai 15:50, 27 June 2007 (UTC)

This -> might also be a useful thing in Word. It reveals tabs, paragraph marks, section breaks and so on. — Shinhan < talk > 13:05, 30 June 2007 (UTC)

project management tool?[edit]

Which free project management software or website can someone use on WinXP to keep track of their goals? For example, I want to give myself the goal of finishing task X by Friday, and task Y by the next Monday, etc. etc.

And I can then update it every day and say that "today I have completed about 40% of task X", and it will then tell me how "behind" or "ahead" I am overall.--Sonjaaa 21:54, 26 June 2007 (UTC)

For something like that, you might want to set something up in Excel or any other spreadsheet application. Donald Hosek 22:59, 26 June 2007 (UTC)
Can't vouch for it but Open Workbench claims to be the free open source alternative to MS Project. If so it can do what you want and make all sorts of nifty charts and graphs to show you how much of a frood you are. 161.222.160.8 23:42, 26 June 2007 (UTC)

Linux install[edit]

I'm considering installing a version of linux (Ubuntu) from a liveCD onto my computer but I'm not sure about one thing. I currently have XP on it, and I know that uses an NTFS system. If I install linux over it (I don't have anything installed that I wouldn't be willing to replace with something else, so I don't mind reformatting), will it automatically change the HD into FAT32 or something else compatible with linux? Or will I need to repartition before I try to install? I know at least the liveCD runs OK on my system as it is now.

Thank you for your time. 76.192.5.108 23:32, 26 June 2007 (UTC)

If you go with dual-boot option, the NTFS partition will remain, but will be resized to accomodate ext3 and linux-swap partitions. If you choose to wipe the disk, you get an ext3 partition and linux-swap. The Ubuntu installer can take care of this. Splintercellguy 00:14, 27 June 2007 (UTC)
Also, I believe Ubuntu 7.04 has native NTFS read/write capability. - Akamad 00:48, 27 June 2007 (UTC)
I think the CD I have is 6.90 though I could of course DL the new one if I wanted to. Thanks for the responses. Mattb112885 01:27, 27 June 2007 (UTC)

I'm quite sure that Ubuntu 7.04 can't resize NTFS partitions on install (but do give it a try). Instead, you'd have to resize the NTFS partition from within Windows, and then allow the Ubuntu installer to place itself in "the largest free continuous space on the drive". The installer will then create two partitions there: one Linux-swap partition, which will be about 1GB at most and one ext3 partition, which will occupy the rest of the drive (and will be where the files are stored). In reality, in terms of partitioning, if I wanted to dual boot, I would resize in Windows first - this is because I don't think the installer can resize NTFS partitions (it might be able to, but even if it can, the Ubuntu installer partition manager takes a very long time to run, because it seems to have an obsession with rescanning the partition table every time you click anything - I should say that a fix is being created for this bug, which we may see in 7.10).

Once you've installed Ubuntu, the packages "ntfs3g" and "ntfs-utils" (the former is installed by default, I think) will allow you to mount and mess around with NTFS partitions. Read-write functionality is also included, but is deemed experimental - that said, I have used the functionality and had no problems, and have discovered that if a possibility exists that data loss or corruption may occur when the Ubuntu driver tries to write to the NTFS, it will simply refuse to do so. Martinp23 11:24, 27 June 2007 (UTC)

You won't be able to read the linux filesystems when running windows, at least with the default set of drivers that comes with windows. If you intend to share data between the two OSs, you might want to create a FAT32 partition that both OSs can mount, or rely on the ntfs read-write support (which may or may not corrupt your data). -- JSBillings 11:54, 27 June 2007 (UTC)
You can also use something like Explore2fs. --cesarb 23:57, 27 June 2007 (UTC)
...or ntfs-3g on Linux. --antilivedT | C | G 05:03, 28 June 2007 (UTC)