Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!uakari.primate.wisc.edu!caesar.cs.montana.edu!ogicse!plains!overby From: overby@plains.UUCP (Glen Overby) Newsgroups: comp.os.minix Subject: Re: Using 2 HD controllers Summary: maybe Keywords: hd controller xt Message-ID: <3012@plains.UUCP> Date: 19 Dec 89 01:29:52 GMT References: <341@trux.UUCP> Reply-To: overby@plains.UUCP (Glen Overby) Followup-To: comp.os.minix Organization: North Dakota State University, Fargo Lines: 38 [I am following up to the net rather than sender since I am asking a question myself] In article <341@trux.UUCP> car@trux.UUCP (Chris Rende) writes: >Summary: Request for information regarding the similtaneous use of 2 hard > disk controllers with 4 hard disks on an XT clone. One controller > and 2 hard disks for DOS - another controller and 2 hard disks for > Minix. I was looking at doing this the other day. If you put the second controler at it's alternate address and on a different interrupt line, then disable the ROM, DOS will never know about it. You will then have to modify xt_wini.c to use the other address and interrupt. I think you will only have to change the #defines, but it could be more subtile than that. It will be a lot more work to support both controlers, but I'd like to see it. Becuase all IBM PC interrupt lines are driven with totem-pole drivers rather than open-collector, you will still not be able to have both controlers on the same interrupt line. It may work, but you will eventually burn out one or both of the driver chips. The ROM in your second controler will be pretty worthless since (I assume) it will assume you want the first drive (0x320), so just disable it. Another problem is that xt_wini (since 1.3, if not earlier) only supports one drive! NEITHER drive is accessable if you change the number of drives in xt_wini to 2. I found this out last night when, after jury-riging the second drive outside the case and accidently grounding out the power supply (fireworks!). At_wini supports two drives (I've seen it work), but that controler is sufficently different that simply stealing code did not work. Did Minix work with the OMTI controler at all?? I tried getting Minix to go with an OMTI a few years ago, but gave up... -- Glen Overby uunet!plains!overby (UUCP) ncoverby@ndsuvax, overby@plains (Bitnet)