Path: utzoo!utgpu!watmath!clyde!att!lzaz!hcj
From: hcj@lzaz.ATT.COM (HC Johnson)
Newsgroups: comp.os.minix
Subject: Re: Hard disk hassles + minix.img format problem
Summary: MINIX/ST Hard disk info on failures
Message-ID: <274@lzaz.ATT.COM>
Date: 18 Nov 88 15:26:52 GMT
References: <5515@louie.udel.EDU>
Organization: AT&T ISL Lincroft NJ USA
Lines: 32




<...Triangle 40 MB drive and SLM804 
<...minix.img

The core of the minix.img bad format problem is that the tos
program is brain damaged.  I recently posted fixes for it.

From the mixed litany on hard disk problems I think you all should
know about the following:

1. MINIX is interrupt driven.  As such it requires no spurious interrupts,
and no ambiguity in whether it will get one or not.  From the various
net reports its clear that the Atari SH204 and BMS-100 do it right.
Also, one can presume that the early Supra does it wrong.

   TOS uses no hard disk interrupts, so it can work perfectly and have
MINIX fail completely.  BTW, UNIX(r) has a  history of breaking computers!
It always does things differently from the manufacturer. Ask any DEC UNIX
GURU.

2. The interaction of a hard disk interface and the floppy is wicked.
If anything fouls up on the hard disk side it ors junk with the floppy
reads and both fail.

3. The stwini.c, as written, cannot handle more than drive 0 on controller 0.
Changing the NDRIVES to n will not do the job.

Howard C. Johnson
ATT Bell Labs
...lzaz!hcj