Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!killer!vector!chip From: chip@vector.UUCP (Chip Rosenthal) Newsgroups: comp.unix.xenix Subject: Re: SCO Xenix/386 and large drives Keywords: large cylinders Message-ID: <439@vector.UUCP> Date: 19 Jul 88 16:10:09 GMT References: <80@iisat.UUCP> Reply-To: chip@vector.UUCP (Chip Rosenthal) Distribution: na Organization: Dallas Semiconductor Lines: 47 In article <80@iisat.UUCP> kevin@iisat.UUCP (Kevin Davies) writes: >Does anyone know whether or not SCO Xenix/386 2.2.2 can handle >hard drives that have more than 1024 cylinders (under ESDI) ? >Is an upgrade to this version required to hande a drive this large ? >Any help or hints would be greatly appreciated. I just spent a few weeks researching a 386 XENIX system with RLL drives. Some of what I found out (much of it thanks to you netfolk out there) is probably applicable to this. There are two approaches. First, you can run the OMTI8627 ESDI/RLL controller with a special version of XENIX. (I believe that there is a second ESDI/MFM controller.) This version, a.k.a. the "ESDI version", replaces the standard hard disk driver with one which talks to the 8627. There is about a $100 premium for this version. I strongly recommend against this approach. First, the 8627 is relatively expensive and slow. Second, it ain't made anymore. I'd be real concerned about if and how SCO will continue to support an obsolete piece of hardware like this. And if you want 2.3 and 3.0 -- which you should -- you need to be concerned about the upgrade path. The second approach is to get a controller which looks like a standard ST506 controller, but in fact talks to ESDI disks. In this case, you can run with the standard 386 XENIX release. My understanding is that the Western Digital WD1007 and Adaptec 2322 do this. The following information is quoted from SCO's 2.2.2 Release Notes (Apr 88): Many hard disks, both standard and nonstandard, can be used by the XENIX System V Operating System as long as the disk controller supports the drive. The disk must interface electrically with the disk controller (usually "ST506"). Controllers supporting other drive interfaces such as RLL or ESDI will work as long as the controller presents an ST506-compatible interface to the bus. The section goes on to say that either the motherboard ROM must contain an entry describing the disk (e.g. heads, cylinders, sectors, etc.), or you can use "dkinit" to define a non-standard set of parameters. So, you should be able to enter the information on a large disk even if there isn't a BIOS entry for it. It appears that if you can find a controller which looks like a WD1003 *and* it requires no funky support routines (e.g. strange .SYS files are required to use it with DOS), then it will work. -- Chip Rosenthal /// chip@vector.UUCP /// Dallas Semiconductor /// 214-450-0400 {uunet!warble,sun!texsun!rpp386,killer}!vector!chip I won't sing for politicians. Ain't singing for Spuds. This note's for you.