Wikipedia:Reference desk/Archives/Computing/2013 November 13

= November 13 =

computer simulation
what are the differences between parallel and distributed simulation — Preceding unsigned comment added by 41.89.56.15 (talk) 06:29, 13 November 2013 (UTC)


 * Well, distributed processing is a subset of parallel processing, but with longer times for communication between nodes. Therefore, distributed processing wouldn't be efficient where lots of inter-process communication and coordination is required.  Now you specifically asked about simulations, but the same limitations apply there as to other processing.  A good example of distributed processing is SETI@home, while something like fluid dynamics simulations (say for weather forecasting) requires too much inter-process communication.  StuRat (talk) 06:42, 13 November 2013 (UTC)

Server 2003: OS not found
I'm exhausted from trying to fix this. I've googled and been to technet and many other sites. I know what the problem is but the many solutions suggested don't fix it.

The problem is that boot.ini, nldr and ntdetect.com are on D: while the OS is on C: They were on C: at some stage. They could NOT have been placed there during my initial install since D: is a RAID volume and was added after the system was up and running. I removed the drives from the RAID volume because I wanted to replace them with larger drives. If I put them back the system boots fine.

Basically I've done all the obvious things:

1. Made sure there is no removable media (stiffy, USB, CD/DVD, etc) in the server.

2. Checked that the BIOS detects the drive and is set to boot first - before CD or other device.

3. Booted with the OS install disk (load RAID driver from stiffy)and run a repair using the recovery console. I can log in to the installation normally.

4. Run chkdsk.

5. Run fixboot.

6. Run fixmbr.

7. Run bootcfg /rebuild and created a new boot.ini (I also copied ntldr and ntdetect to C:\)

I am stumped. I feel I am missing something. UltimateBootCD (one of my favourite tools) is of no use because it does not support the hp proliant ml150 embedded SATA RAID controller. 196.214.78.114 (talk) 13:03, 13 November 2013 (UTC)

Windows7 Command line command to eject CDs and USB-drives ?
In the Windows7 GUI i have to right click on the device and choose "Eject". How do I accomplish the same from the command prompt ? --46.15.204.16 (talk) 15:33, 13 November 2013 (UTC)


 * mountvol path /D, where path is the path at which the usb stick volume is mounted (which may be a UNC format path or just something like F:\). Just typing mountvol by itself lists all the mounts it can find. -- Finlay McWalterჷTalk 15:53, 13 November 2013 (UTC)


 * «Access is denied.» is the only result i get when i try: C:\Users\My Username>mountvol f:\ /D …Which I find strage because my active user name shows up in Control Panel\All Control Panel Items\User Accounts as: My Username,Administrator,Password protected. (The current mountpoint F:\ is an optical drive which does appear in the list of current mount points. And I get the same error message both with and withou any DVD in the drive.) Any further ideas for what I might try? --46.15.204.16 (talk) 18:42, 13 November 2013 (UTC)
 * Your account is an administrator, but are you running the command with administrative permissions? With UAC on Windows Vista onwards it is unlikely you are unless you specified it. I don't think there's a simple way to request elevated privileges (at least for the same user) like there is for *nix with sudo . If you are using a command prompt like cmd.exe or Power Shell, it's probably simplest to just start your command prompt with Administrative permissions (e.g. ctrl+shift before starting, right click and choose to run with administrator permissions) presuming you aren't concerned about that. Nil Einne (talk) 06:32, 14 November 2013 (UTC)


 * Thank you both! :-) --(OP) 46.15.66.100 (talk) 09:22, 18 November 2013 (UTC)

Request unban on Google Groups
I am banned on one of the Google Groups. How to request the forum administrator to unban me? Czech is Cyrillized (talk) 16:08, 13 November 2013 (UTC)

Home networking with phone lines
Dear Wikipedians:

My house has lots of telephone line (RJ11) jacks, almost one in every room. I was thinking of home networking my computers in different rooms with these jacks. I have done some preliminary research on the Internet and found out that a standards organization known as HomePNA has published standards enabling computers to communicate with each other over telephone lines. However, I was unable to find actual equipments (adapters, expansion cards) that does the actual networking on TigerDirect. I was wondering if any of you know where to I can find such equipments.

Many thanks.

http://computer.howstuffworks.com/phone-network.htm

76.75.148.30 (talk) 16:38, 13 November 2013 (UTC)


 * I take it that you're in Canada, so this Linksys stuff should work. Compare it to the cost of WiFi first then get back and let us know either way. The benefit is that it will be harder for outsides to use snifters to capture your banking transactions etc.--Aspro (talk) 18:52, 13 November 2013 (UTC)


 * Thanks. That is exactly what I was looking for! 74.15.97.233 (talk) 21:10, 13 November 2013 (UTC)

Wii remote not pointed at screen, cursor still showing up on screen
Every so often, I have an issue with Netflix where I'm trying to watch a movie or show and the cursor for the Wii remote shows up on my screen which brings up the on-screen controls. Even though the remote is pointed away from the TV, the controls will sometimes pop up. When the problem gets too much to handle, I'll sometimes just remove the batteries from the remote but then I have to put them back in if I want to do anything like pause the movie. The issue isn't a problem with games and such since that's when you actually want the cursor to be on the screen. That's what is causing problems with my Google-fu. I keep finding results for problems with calibration and the cursor not showing up when it should. My issue is that it shows up when it shouldn't. I haven't noticed any correlation between the time of day or anything else.

Long story short, how can I convince the remote that it's not pointed at the TV? Dismas |(talk) 18:49, 13 November 2013 (UTC)
 * If I remember my sister's Wii correctly, the remote has in infrared emitter and there is an infrared sensor we had to fit to the frame of the TV. While your Wii remote is facing away from the sensor, could the sensor be picking up stray infrared signal either bounced from the walls of your room or from another source, say the TV remote?  The Wii Remote article has some details how the system works.  Astronaut (talk) 19:59, 13 November 2013 (UTC)


 * Astronaut has it exactly backwards, actually.  The "Sensor Bar" that you put on your TV is the IR emmiter, and the wii-mote has an IR camera in the end.
 * But Astronaut has the right idea. I'll bet that the wii-mote is pointed at OTHER ir source. Possibly a candle, possibly, an incandescent light-bulb, or possibly a mirror that allows it to see the reflection of the "Sensor bar".
 * Next time you watch a movie on your wii, try to put the Wii-mote down so that the tip is pointed at something you're SURE isn't putting out IR. Or just cover it with something. APL (talk) 21:56, 13 November 2013 (UTC)

(EC, saying similar to APL)
 * No, that's backwards. The so-called "sensor bar" that you put on the TV is an IR emitter, and it's the Wiimote that "sees"/senses the light shining out from the bar. Then the Wiimote talks to the Wii base via bluetooth to tell it what it saw, etc.... (fun fact: you can unplug the "sensor bar", replace it with two tea candles, and everything will still work fine!) anyway, your idea still has merit: perhaps the wiimote is sensing other IR when the OP points it elsewhere? Also, clarification from the OP: does the problem occur with wiimote only, or do you have other bits and bobs plugged in? For example, if you have a "classic controller" plugged into the wiimote, you can use the sticks on the classic to move the pointer on screen, even if the wiimote is pointed elsewhere. In that instance, the pointer is supposed to stay on screen, even when the wiimote is pointed away. SemanticMantis (talk) 22:01, 13 November 2013 (UTC)

Thanks, everyone! Yes, the emitters are in the bar on the TV and the receiver is in the Wiimote. And now that you mention the reflection idea, I think that's what it might be. There are framed photos on the opposite wall which is in the general direction that I had been pointing the Wiimote. Maybe next time I'll try putting something over the Wiimote. I wasn't aware that candles could be used instead of the IR bar on the TV though! That's pretty neat! Thanks again, Dismas |(talk) 02:07, 14 November 2013 (UTC)