Wikipedia:Reference desk/Archives/Computing/2009 September 25

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.

September 25

Dual Quad Core i7 possible?

Is it possible to build a computer with two quad core Intel i7 chips (8 cores total)? Or is a Xeon better suited for multiple chips on a motherboard? --68.103.141.28 (talk) 00:23, 25 September 2009 (UTC)

I don't know of any technical reason why you can't. However, you'd need a motherboard that supports two i7 processors and as far as I know there aren't any commercially available (yet?). I'm happy to be proved wrong though! ZX81 ^talk 00:52, 25 September 2009 (UTC)

True Crime nyc ps2 - editing

I own it on ps2 , is there a way to mod it by using some kind of software or an application? I really want to choose another player model to play as.

IS THERE ANY F***ing way to EDIT PS2 GAMES!? 85.220.102.101 (talk) 17:53, 26 September 2009 (UTC)

Macbook broken screen, please help

The screen on Justin's macbook is messed up. Here's a picture: http://www.flickr.com/photos/hadakushal/3939622349/

Any ideas what happened here? Will just replacing the LCD screen fix the problem? Maybe? Need more information to answer?

I was wondering if buying a non-Apple part would be worth it. This one http://cgi.ebay.com/screen-13-3-lens-for-Apple-Mac-macbook-13-3-inch_W0QQitemZ280399759286QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item414920c7b6&_trksid=p3286.c0.m14 is $24. The cheapest ones that claim to be original part run $75 dollars. I also found this guide http://www.ifixit.com/pdf/guide_536_en.pdf and while not easy, it looks straightforward.

Looking forward to your reply ... Kushal (talk) 11:47, 25 September 2009 (UTC)

Jeez, that looks not so good. What happened to it? You usually don't just wake up one day and have it look like that. I'm not really sure what the issue is—I would take it first to an Apple store, show it to them, have them diagnose it. Then you can figure out whether you want to try and do the labor at home. It's a real chore to replace the screen, as you can imagine, but if you can do it yourself, it's obviously cheaper than having them do it. --Mr.98 (talk) 14:26, 25 September 2009 (UTC)

I think you are right, Mr.98. I never asked the complete details in this case. I am not entirely sure how it started. However, once it did, it just kept growing until it became what it is today. :( We don't have Apple Care anymore. Is it worth it to drive to an Apple Store? The closest one here is just shy of a quarter to three hour drive. :( Kushal (talk) 09:56, 26 September 2009 (UTC)

That looks like a hardware problem with the screen itself. If replacing the screen isn't doable, you could also hook the laptop up to an external monitor, although obviously at the cost of reducing portability. StuRat (talk) 12:59, 26 September 2009 (UTC)

That is a possibility, StuRat. I guess I would be needing a mini DV port adapter for whichever monitor I choose. ... maybe something that doubles as a television even! I will probably query Justin about it. He likes taking the computer to class and such though (he is in college). I would probably want to go with the least expensive solution, though. and nothing seems to beat a 25 dollar screen. ... any ideas? Kushal (talk) 18:06, 26 September 2009 (UTC)

I'm not speaking from experience on this, but it seems highly unlikely to me that the $25 screen is going to be an adequate replacement. Sounds too good to be true. I would seriously look for some reviews. It's only the cheapest option if a) you don't count your own time as valuable, and b) it doesn't immediately break again or cause other difficulties. If I were going to replace the screen, I would probably opt for original parts, esp. with Apple (where everything is about original, proprietary parts).

Taking it to the Apple store won't cost anything—they ought to be able to tell you if it's a screen problem or something else. (Even just hooking it to an external monitor would tell you something, as well.) A cheap LCD monitor will cost about $120. The Mini-DVI->DVI or VGA plug costs $19, usually. --Mr.98 (talk) 20:27, 26 September 2009 (UTC)

Thanks guys. I found a decent Asus 21" monitor on Amazon for ~ USD 150 and Mini-DV to 24 pin for about fifteen dollars more. It is starting to look like a very good alternative. Kushal (talk) 04:48, 27 September 2009 (UTC)

recovery shutdown

i have aprblem that is when i start my laptop the windows vista is loaded smoothly but sometimes i heard asound like fast ticking the ablue screen pops up showing shut down recovery and stuff like dumping physicsl memry.what do you think the problem is?

First, back up everything on your hard disk, probably most easily done by copying it all to an external USB hard disk during one of those times you are able to successfully boot Vista. The problem is probably a corrupted OS, though before you try to address the problem, you might as well download memtest86, create a boot CD, and boot up your computer with it, letting it run a complete memory test for a cycle. This will highlight problems with your computer's RAM, which could be the cause of the blue screen problem you're seeing. Then I would start from scratch: Reformat your hard disk, deleting everything on it, and reinstall everything from scratch. I would normally first suspect corruption of the OS for some reason. (When you reinstall Vista, be sure to make an "admin" account that has administrator rights, and a "user" account with no administrator rights; and use the "user" account whenever you use the computer. This helps prevent viruses, trojan horses, and other malware from infecting your OS in the future.) Comet Tuttle (talk) 18:06, 25 September 2009 (UTC)

I would guess that the "fast ticking" is a hard disk trying to seek and failing. It seems likely that it would be better to grab what's possible of the hard disk and if the OP can do this, to replace it. Otherwise they might be looking at a new machine. --Phil Holmes (talk) 11:06, 26 September 2009 (UTC)

Recovering Last Session After a Crash on Firefox and a Dumb Mistake

I'm running firefox 3.5.3 and had a crash. Unfortunately, when it restarted I accidentally clicked the 'start new session' button rather than the 'restore my previous tabs' button. Now I'm staring at google instead of the 10s of research pages I had open in mid project. Is there any way I can get that last session back?

Your history may still contain those pages even if the session crashed, (depending on how the crash happened). You might consider bookmarking those pages as well; you can use the new "bookmark all" feature to save an entire browsing session with a single "bookmark". Nimur (talk) 21:05, 25 September 2009 (UTC)

I don't have a solution to restore your lost tabs, but I would highly recommend the Session Manager addon to prevent something like this happening again

replace only new and updated files

I have all of my files in a folder, with a nice and organized directory structure. I want to keep a copy of this folder on a couple of computers, and use an external hard drive to sync it up. What I'd like to do is at the end of the day, just drag the top level folder onto the external drive and have the system only copy the new files and only overwrite the files which have been updated. The computers in question are using vista, and xp.

When I try this in XP, the message I get is "If the files in the existing folder have the same name as the files in the folder you are moving or copying, they will be replaced. Do you still want to move or copy the folder?". So I don't have the option of only replacing files that are new or updated, and don't want to waste my time overwriting files I don't need to. In Vista the exact message is different, but the result is the same: no conditional copying command.

Is there any way to do this? Do I need to use another (preferably free) program besides windows explorer? Thanks for the help mislih 15:36, 25 September 2009 (UTC)

Well, Windows Vista is actually a lot better than XP in this regard. Explorer asks you if you want to merge the folders. But still there is no "copy only newer versions" option. However, writing such a program is almost trivial, so surely there are quite a few available on the Internet. --Andreas Rejbrand (talk) 16:24, 25 September 2009 (UTC)

I use xcopy to do this. If you use the following syntax: "xcopy /s /d /y /c sourcefiles destination" you should get what you want. If you save this as a .bat (Batch file) then all you need do is double click the batch file to synch up. As an explanation, /s does all subdirectories, /d does what you want - copies new/newer files, /y suppresses confirmations and /c supresses errors. HTH. --Phil Holmes (talk) 16:44, 25 September 2009 (UTC)

Nobody has yet mentioned Windows Live Sync, which is the official tool from Microsoft and is included on newer versions of Windows. If you wish to use the Microsoft servers as the provider, you are limited in total storage space; but if you choose to run your own server using the Windows Server, you can operate an arbitrarily large data synchronization. You can also read about the Microsoft Sync Framework for more industrial-strength synchronization. Nimur (talk) 18:16, 25 September 2009 (UTC)

If using xcopy, /h (copy hidden and system files) may also be useful. Run xcopy/? to see all the switches, and what they do. Also you might want to try robocopy, which includes all sorts of extra capabilities. It comes with Vista, but I believe it will also work on XP. Again, /? should show you all the switches (and there are a lot of them!). Mitch Ames (talk) 01:27, 26 September 2009 (UTC)

Or Teracopy. ---— Gadget850 (Ed) ^talk 18:27, 25 September 2009 (UTC)

Inkspace

How can I use Inkspace? --ArgGeo (talk) 5:30 pm, Today (UTC+2) User talk:ArgGeo

Moved from WP:VP. Svick (talk) 16:18, 25 September 2009 (UTC)

First, you need to download it, instructions and links here. Here are the official tutorials. Do you have a specific problem? Nimur (talk) 16:40, 25 September 2009 (UTC)

For your future searching and such, you should note it's called Inkscape, not Inkspace. --Sean 20:54, 25 September 2009 (UTC)

How did they disable the back button?

Go to the Asheville Citizen-Times web site[1]. Look at any article that has more than one page. Read each article one page at a time. When you get to the last page, click on "Back". You only have to do it once.Vchimpanzee · talk · contributions · 19:53, 25 September 2009 (UTC)

The hyperlinks are not to a URI, but instead serve to actuate a javascript tool to load new content. Such use is common on rich content websites (often using AJAX, DHTML, etc.), although it is discouraged by standards organizations like W3C because it results in stateful URIs. See the section in our HTTP article and also computational idempotence for more technical details about why such design is discouraged (these articles are fairly technical and theoretical - but they are conceptual ideas that are part of the HTTP and web architectural standard). This section, Protocol Parameters for the official HTTP specification, explains in technical detail why the news site Vchimpanzee linked is technically "broken" according to strict interpretation of standards - it uses the same URL to refer to multiple documents based on the user's Javascript state. Nimur (talk)

On a related note, to make printing out the articles cheaper, I copy and paste the text and put it in an email to myself with all the white space removed. The entire article appears even if I never go to the other pages.

On another site [2], there are links to other articles on the page with each article but when I copy and paste those articles the first few words of the actual article appear--not just the names of the articles! It's very annoying if I'm trying to save money, not to mention it makes the result harder to read.Vchimpanzee · talk · contributions · 20:39, 25 September 2009 (UTC)

Again, like many complex websites, they use JavaScript to override default behavior, including copy/paste. Nimur (talk) 20:57, 25 September 2009 (UTC)

Note that in this case, "complex" is synonymous with "poorly designed, from a user's point of view." One should never use Javascript to override things like basic copy and paste behavior. --Mr.98 (talk) 21:48, 25 September 2009 (UTC)

Agreed. What is to stop a user from disabling javascript just on that website? Kushal (talk) 10:01, 26 September 2009 (UTC)

That will make many such sites unusable, since they're usually not good at making their masterpieces "unobtrusive". Greasemonkey is a better solution in my experience. --Sean 11:02, 26 September 2009 (UTC)

UDP and throttling

Suppose I am playing a hypothetical first-person shooter that broadcasts my character's position by blasting out UDP packets over a Gigabit Ethernet LAN at maximum speed, saturating the network. This is awesome! All my friends' machines know precisely where I am, many times per second! Now suppose I connect my Gigabit Ethernet router to my DSL modem which has an uplink speed, typical as I understand it in the USA, of only 768Kbps. That's under 1/10th of 1% of the bandwidth I'm using for LAN play. How does the throttling occur? Does the router itself discard 99.9% of the UDP packets? Or does it perhaps discard a mere 90% of the packets and fire the other 10% of the packets to the DSL modem via its link at 100Mbps Fast Ethernet speed, and then the DSL modem in turn discards another ~93% of the resulting packets as it uploads them to my ISP's connection? And in all cases, how do the router and modem determine which UDP packets to discard? Comet Tuttle (talk) 22:17, 25 September 2009 (UTC)

What is the destination_ip_address set in these UDP packets? -- 87.115.106.169 (talk) 22:23, 25 September 2009 (UTC)

This is all hypothetical, so I guess it would be the IP address of some other guy playing against me, a few cities' distance away. Comet Tuttle (talk) 22:52, 25 September 2009 (UTC)

Games don't flood networks with an infinity of packets (at least not since Doom); indeed games are generally very economical, sending as few packets (and as small) as they can get away with (without causing jumpiness or obvious interpolation/extrapolation artifacts). Packet loss will occur only when the network is saturated for some other reason. -- 87.115.106.169 (talk) 23:04, 25 September 2009 (UTC)

In other words, the software of the game does the throttling, by sending an intelligent number of packets. Even if your connection is fast, the software will not blast out packets at megabytes-per-second data rates. It has been designed not to use (and not to need) this data rate.Nimur (talk) 23:25, 25 September 2009 (UTC)

Sorry, I should have been more clear. I am asking specifically about how exactly the router/DSL modem setup above would throttle a large amount of UDP data, not about how a well-designed (or even adequately-designed) game will handle the situation. I only mentioned my hypothetical game as an example, but it might as well be a video broadcast application. I am indeed asking about a situation where the network is totally flooded with UDP packets. Comet Tuttle (talk) 03:32, 26 September 2009 (UTC)

The throttling device (the DSL router in your case) will initially delay the packets and will then drop them once its queue is full. If you were usin TCP your sending process would not receive the ACKs to say they had been received and so would slow down. With UDP the network does not provide that feature, and so by default your process would continue sending them and they would be dropped by the router. A well designed process (the game) would communicate with the far end machine to check arrival and would slow down, like the TCP does - but the game writer would have to do this. --Phil Holmes (talk) 10:12, 26 September 2009 (UTC)

More about accessing a 1541 from a modern PC

So I've ordered an XM1541 adapter cable, but it hasn't arrived yet. I originally thought I could attach it to a modern PC with a parallel-to-USB adapter, but apparently those won't work. I do have another option - I just found out my father's company has at least one many years old laptop, which still has an old-style parallel port. I could, in theory, copy the files to that laptop if I borrowed it from my father's company. But how do I get them from there to my own system then? I'm not sure if the laptop has any USB ports, so memory sticks might not be an option. It has a CD-ROM drive, but I'm not sure if it's a recording drive. I couldn't get the laptop to connect to the Internet when I tried to help my father set it up at his home. A last resort would be to physically remove the laptop's hard drive and put it in my own computer, but I don't think you can do that with laptops, only with desktops. Do I have any other options? JIP | Talk 23:52, 25 September 2009 (UTC)

I don't install hardware often, so I'm not always up to date with modern computer hardware. But if your computer has an available PCI slot, I think you could purchase and install a PCI parallel port card? Then you could use the XM1541 cable with your computer's new parallel port and avoid having to use a second computer at all. --Bavi H (talk) 01:41, 26 September 2009 (UTC)

Yes it has available PCI slots. I'll just have to see where I can get a PCI parallel port card then. JIP | Talk 07:42, 26 September 2009 (UTC)

Hey, wow! These are even available at Verkkokauppa.com so I don't even to have to order one from abroad! I found that trying to find a USB parallel port replicator is next to impossible, but apparently PCI parallel port replicators can be found like mushrooms in the rain, like we say here in Finland. Installing PCI devices is a bit trickier than simply plugging in the plug, but I've done it before many times, back in the days where EtherNet devices didn't come integrated into motherboards, but you had to buy and install them separately. JIP | Talk 07:49, 26 September 2009 (UTC)

If you did want to go down the "transferring by using the hard disk" route, you could get a USB->2.5" disk adapter. --Phil Holmes (talk) 10:18, 26 September 2009 (UTC)

I ordered a PCI parallel port replicator from Verkkokauppa.com. Now I need to wait for both items to arrive, then load a 1541 driver for Linux from the... Internets, and then I should be in business! I just had a look at the box of Commodore 64 disks I have and went all nostalgic just from looking at them. There's about 100 of them, and with 330 kB each, it comes to 33 MB. That's one-thirtieth of the smallest-capacity USB memory stick on sale nowadays, and that would fit in my back pocket. JIP | Talk 17:48, 26 September 2009 (UTC)

But you can't double the capacity of a USB stick with a paper hole punch. 69.245.227.37 (talk) 23:15, 27 September 2009 (UTC)

The PCI parallel port replicator arrived today. I installed it without difficulty, and the computer booted back up all OK. I haven't actually tried to use it for anything. Still waiting for the XM1541 cable. JIP | Talk 16:42, 30 September 2009 (UTC)