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Path: sserve!manuel.anu.edu.au!munnari.oz.au!network.ucsd.edu!usc!wupost!crcnis1.unl.edu!moe.ksu.ksu.edu!maverick.ksu.ksu.edu!news From: brtmac@maverick.ksu.ksu.edu (Brett McCoy) Newsgroups: comp.unix.bsd Subject: Re: Finding untranslated params for IDE drives (w/ pgm) Date: 20 Oct 1992 00:43:13 -0500 Organization: Kansas State University Lines: 39 Message-ID: <1c069hINNimd@maverick.ksu.ksu.edu> References: <1992Oct18.153007.28120@crash> <1992Oct19.053131.11296@tfs.com> <1992Oct19.173418.10490@fcom.cc.utah.edu> NNTP-Posting-Host: maverick.ksu.ksu.edu In <1992Oct19.173418.10490@fcom.cc.utah.edu> terry@cs.weber.edu (A Wizard of Earth C) writes: >In article <1992Oct19.053131.11296@tfs.com> julian@tfs.com (Julian Elischer) writes: >>this [IDE data] is great, Terry and I were trying to work out the translation >>mechanism, so we could better understand the boot. >>Terry feels that the translation in IDE drives is done by the BIOS >>support routines, though I was dubious about this (but hey >>I don't have an IDE drive so what do I know) >>This however is the second confirmation of the drive doing it itself, >>so it loks as if at least SOME of them do it on the drive. > >I guess this then raises the question: why the heck are the 0xec/0x91's >used at all? Turning off translation makes no sense, then, since the only >apparent effect is to screw up installation for 2/3's of the people with >IDE drives. Why does the WD driver screw with it? > >The only potential explanation is non-IDE drives (like the 9 head MFM >Micropolis, 130M). Getting the drive geometry would give you more disk >space to use. One reason to turn off translation is so that that all the fancy Berkeley Fast File System stuff can do it's thing. All the calculations that it does don't mean a thing if the geometry is getting translated. Now, the MAXTOR 7120A throws a kink in this. There are four different "default" translations you can set the drive in (meaning, after a reset this is what the drive will claim to be), and non of these is the actual geometry of the disk. If you want to use that you have to tell it to use that as a translation. However, since 386BSD shuts off translation there is no way to use the actual geometry of the disk, only one of the "default" translations settable by the jumpers on the drive. The native geometry of the drive has more sectors than is accessible by any of the translations, and I imagine accessing the drive in it's natvie geometry would be faster than any of the translations. Being able to run 386BSD without it throwing the drive back into it's default setting would be a boon, I think, to me. ++Brett;