Wikipedia:Reference desk/Archives/Computing/2007 July 25

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[edit] July 25

[edit] Windows Media Player woes

I own a HP Pavilion desktop PC with Windows HP Home Edition. For the past few days, I've had trouble playing burnt CD's on my computer. It had Windows Media Player version 9, and no matter how many times I try, they just won't play, and if I try to acess the E drive, it lists it as "drive busy". Before this, the burnt Cd's would work just fine. The CD's work fine on a regular CD player, though.

I've recently updated to version 11, but still no dice. Is it something on my end, or is my PC on the fritz?

Note: My PC is infected by a few trojan viruses; are they somehow related?

It sounds like the CD drive on the computer may be the problem. Did it used to work on those same music CDs ? StuRat 06:24, 25 July 2007 (UTC)
Very hard to diagnose this remotely. Could be a loose cable to the drive. Could be a stuffed drive in which case just pick up another one for $20 to $30. Did you try rebooting? Did you install any software with copy-protection or, even worse, software that tries to crack the protection? The protection or the crack could attempt to "blacklist" your drive and make it completely inaccessible, to the point of reinstalling windows. Or it could be a virus that has corrupted your cd-rom driver. Etc. Etc. Sandman30s 12:40, 25 July 2007 (UTC)
Even worse, you can sometimes install copy-prevention software by just putting a music CD in your drive (for instance, the Sony rootkit). That's why you should always disable autorun. --cesarb 13:42, 25 July 2007 (UTC)

StuRat: Yeah, the burnt CD's would work just fine before.

Sandman30s: I installed Windows XP updates about a couple weeks ago, and I've had no problems since...unless the instalation of these updates straight from Microsoft was the cause...

I've completely disabled windows updates and firewall due to lots of problems. I've installed a third-party virus checker which has its own firewall. One thing from Microsoft that does work however is the System Restore - if you can afford to restore your system (and this won't delete downloaded files, it just restores system files and settings) to before the updates kicked in, it might resolve your problem (not necessarily caused by the updates but anything else that may have auto-installed during that period) Sandman30s 13:40, 26 July 2007 (UTC)

I forgot to mention: Any other CD will work on my PC; burnt ones of any kind or make just won't play.

[edit] Huffman tree implementation?

Since my previous question is getting out of the attention span and into the archives I will post a new question instead. I have decided to use Huffman coding to compress my ASCII text and have done the data distribution analysis (Ah good ol' uniq -c). However I have no idea how to use this data: I've used a software here to generate the binary representations but I do want to see how it is generated and write my own programme. I'm also quite clueless about how to implement the compression scheme: I know you can just trace down the tree and see what the code end up with but how do you implement that in software? The things on binary tree is quite complicated and I still don't have a mental picture of how this is actually implemented in software. Can anyone give me some pointers and maybe some snippets of C code to demonstrate how it is implemented? --antilivedT | C | G 06:13, 25 July 2007 (UTC)

Can you program a tree (not necessarily a binary tree)? Do you understand the concept of nodes and pointers? You can't make the leap to Huffman coding without knowing how to program the underlying structure. -- Kainaw(what?) 13:47, 25 July 2007 (UTC)
I strongly echo this. Binary trees are a fundamental data structure and if you want to program anything advanced you need to understand them. I'd recommend checking out Introduction to Algorithms from the library. It's a tome, but it's fairly simple and introduces a whole lot of concepts (including binary trees) in a very good way. If you're feeling adventurous, you can also look at Vol 1 of The Art of Computer Programming, but that's a HARD book. --Oskar 18:24, 25 July 2007 (UTC)

[edit] Alternate DNS

What is alternate DNS in domain client environment.

Maybe WINS? --TotoBaggins 14:04, 25 July 2007 (UTC)

[edit] USB flash drive as RAM

I want to ask that.. how a USB flash drive can be used as RAM for pc?

suppose I have a 512MB pen-drive..I want to use it as RAM ,so i can increase my pc's speed.......

please send me some note regarding to this.. my e-mail adress is e-mail address removed. please send me.I am waiting for your reply....

I don't know of any way to use a flash drive as RAM, but I can assure you that it would do nothing to speed up your PC, as the USB bus is quite a bit slower than your motherboard. --LarryMac | Talk 13:20, 25 July 2007 (UTC)
If you have Windows Vista you may be interested in ReadyBoost. — Matt Eason (Talk • Contribs) 13:33, 25 July 2007 (UTC)
Might be able to move your virtual memory, paging file, whatever you want to call it to the flash drive instead of the hard drive, if it's not bigger than the flash drive is. Seems like that oughta work; we used to do stuff like that in Ye Olde Dayes. Gzuckier 14:29, 25 July 2007 (UTC)
Flash would make a terrible paging device. Not only is it slow and power-hungry when it's writing, it also has a wearout mechanism that limits its life to between 10,000 and about 1,000,000 writes. Stick to magnetic disk for now.
Atlant 15:24, 25 July 2007 (UTC)
Well of course, in Ye Olde Dayes the access time of a hard drive was about a week. Gzuckier 19:16, 26 July 2007 (UTC)


Slow for sequential I/O, but lightning fast for random access. Perfect for paging. --frotht 16:10, 25 July 2007 (UTC)
No, slow to write. It takes time to fire up the charge pump and get the writing voltages stabilized, takes time to tunnel those electrons through to the floating gates, and so on. But yeah, after you wait through all that, they at least read pretty fast.
Atlant 21:34, 25 July 2007 (UTC)
Also the write/read cycles of flash drives are mostly (according to the wikipedia article) guaranteed at least 1,000,000 cycles. I'd confidently expect flash memory to replace platter-style hard-drives in laptops in the not to distant future. ny156uk 21:18, 25 July 2007 (UTC)
It varies from part to part. One of the parts I use ranges down to 1,000 cycles on some of its flash (that programs some array logic) and 100,000 cycles on the rest (which is pretty-ordinary NAND flash). The other part is rated 5-10,000 cycles. But you don't have to believe me; for any given part, the manufacturer's datasheet is the ultimate authority.
Atlant 21:38, 25 July 2007 (UTC)
I read a thing in Wired, I believe, that showed a performance boost only when using a $200 flash memory card. Buy RAM instead. -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 21:57, 25 July 2007 (UTC)

[edit] briefcase

I don't know how to use the briefcase folder. pl. help me how can i make use of the briefcase folder. thankyou124.43.245.105 12:34, 25 July 2007 (UTC)

It's for synchronizing files with another device like a networked computer or flash drive --frotht 16:11, 25 July 2007 (UTC)

[edit] Dark web

Though I mainly use Google as my search engine, I was wondering what were some other search engines or search methods that I could use to penetrate the dark web to find results that I may not normally find on Google. —Erik (talk • contrib) - 13:19, 25 July 2007 (UTC)

Do you mean Dark web or Deep web? The dark internet is, by definition, inaccessible. Our article on the deep web has a section called Crawling the deep Web which might be useful to you. --HughCharlesParker (talk - contribs) 13:58, 25 July 2007 (UTC)
Or do you mean Metasearch engine ? --racergr 04:59, 27 July 2007 (UTC)

[edit] ls replacement for tree

I have a server that does not have 'tree', so I can't use 'tree -fid' to get a nice list of all files with prepended directories, ie:

#tree tmp
tmp/
tmp/somefile.gif
tmp/anotherfile
tmp/subdir/
tmp/subdir/morefiles.doc

Is there a relatively unknown series of flags for 'ls' to make it perform in a similar manner? -- Kainaw(what?) 13:43, 25 July 2007 (UTC)

How is the above different from just typing "find ."? --TotoBaggins 14:07, 25 July 2007 (UTC)
From my experience, 'find' does not list directories. -- Kainaw(what?) 14:18, 25 July 2007 (UTC)
OK - it helps if I test it on a directory with subdirectories. -- Kainaw(what?) 14:37, 25 July 2007 (UTC)

[edit] uploading clip to refrence desk

okay i have this clip and i need some help uploading it to wikipedia reference desk.av tried using the upload wizard but its says .wav is not an allowed format. it also doesn't accept .mp3 format.how do i uploadit so i can be helped.its my entire work and its not copyrighted. —Preceding unsigned comment added by Ianmwash (talk • contribs)

putfile.com? --frotht 16:11, 25 July 2007 (UTC)
Convert it to .ogg, then upload it. --Wirbelwindヴィルヴェルヴィント (talk) 17:05, 25 July 2007 (UTC)