On Tuesday 21 November 2006 08:54, Tim wrote: >On Tue, 2006-11-21 at 21:21 +0800, Mel wrote: >> AFAIK, the jumpers also select whether or not the drive uses >> terminators. The master has the terminators and the slave does not. >> The terminators must be at the end of the cable or reflections may >> occur. At higher speeds these reflections are important. > >IDE/ATA doesn't use termination, SCSI does. Yes it does, they just tried to make it so automatic the user isn't aware of it. And its worked fairly well, removing the stigma of having to sacrifice virgins to get a scsi setup working. For starters, the 'master' drive or the drive set for 'single' does it, and it MUST be on the end of the cable for exactly the same reason that the last scsi device on that cable must be on the cables end connector. If it is not, then the terms must be disabled and termination devices plugged into that last end connector. Any unterminated cable hanging out past the point of the termination will cause data destroying echo's on the cable. Why is it that just because its not mentioned, everyone thinks the laws governing electrical transmission lines are repealed in the case of an ide/atapi cable? Tain't so folks. You are argueing in a field of knowledge I'm intimately familiar with with my 60 years in electronics, 44 of that in broadcast. There, we call it VSWR, but the cause and effect are exactly the same. >-- >(Currently testing FC5, but still running FC4, if that's important.) > >Don't send private replies to my address, the mailbox is ignored. >I read messages from the public lists. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
