Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!wuarchive!usc!sdsu!crash!pnet01!jca
From: jca@pnet01.cts.com (John C. Archambeau)
Newsgroups: comp.os.minix
Subject: Re: minix 1.3 on 386/vga/rll system
Message-ID: <913@crash.cts.com>
Date: 17 Dec 89 06:56:04 GMT
Sender: root@crash.cts.com
Organization: People-Net [pnet01], El Cajon CA
Lines: 64

car@trux.UUCP (Chris Rende) writes:
>I'm running Minix 1.2 on an XT with a SMS OMTI 5510/5520 HD controller using
>a modified xt_wini. I have 1 ST-213 disk (10Mb: 612 cyl, 2 hds) and
>1 ST-412 disk (10Mb: 306 cyl, 4 hds).
>
> [ ... explanation of problem with OMTI 5510/5520 which I'm VERY
>       familiar with, but got very tired of mucking with.        ]
 
I'm very familiar with the OMTI 5520A.  And there's a bit more than getting
around the parameters.  There's a problem with DMA as well, at least with my
system there was.  I finally chucked the thing for a WA3-16 (WD1003-WA2 clone)
controller, Minix works great now.  Although CTRL-ALT-DEL reset makes the
system hang when Minix is rebooted and = is hit.  I believe I have the patch
for that somewhere.  Apparently it deals with resetting the 16-bit AT drive
controller.

>Note that in my case I had to have a HD controller which allows the two
>disks to have a different geometry. I <think> that some OMTI 5510
>controllers don't allow this.
 
The 5520A will allow it, but you have to enter the parameters at low level
format.

>The next problem I had was fsck. (Talk about a program with lots of magic
>numbers all over the place!). It took a bit of looking around to find that
>fsck was hardcoded to think that the HD has 4 heads. But, don't look for
>the string "HEADS" anywhere, don't look for "4" anywhere, no, you have to
>look for "68". Yes, that's the number. You see, "68" is "4*17". Or, 4 heads
>times 17 sectors.
 
Maybe I should have made myself clear, in fsck.c there's a define for the
number of heads, but maybe not in 1.2.  I don't know why you'd be running 1.2
anyway unless you just can't get 1.3 anywhere or it's just too much of a
hassle to get (which I believe is the sole reason why people are still playing
with 1.2 which has some problems, 1.3d is clean for most part).
 
As for controllers, I can not emphasize enough about getting one that is as
Western Digital compatable as you can get.  It saves a lot of wear and tear on
the user.  If anybody is planning on buying a system just for Minix, make
sure the hard drive controller is Western Digital compatable.  The WA3-16 I
personally certify as being WD1003-WA2 as far as Minix is concerned.  I
haven't tried the WA6-V yet which is Kimpsion International's WD1006V-MM2
clone, but I'm sure it will work because of how good the WA3-16 has been.

As Minix evolves, the need to develop standards to get around certain problems
such as hard drive parameters will have to be developed.  Since Phoenix has
put out a BIOS manual that I have seen, it's a trivial matter of now getting
documentation of where hard drive parameters are stored for an AT with an AT
controller, but what if you have an AT with an XT controller?  Or an XT?  Then
there's a problem since everybody (Scientific Micro, Adaptec, Western Digital
(which is the de facto standard), Future Domain, etc.) does it differently. 
So what do we do?  Well, one can have a methodology for overriding hard drive
parameters.  These things will be developed during the evolution of Minix.
 
     // JCA

 /*
 **--------------------------------------------------------------------------*
 ** Flames  : /dev/null                     | My opinions are exactly that,
 ** ARPANET : crash!pnet01!jca@nosc.mil     | mine.  Bill Gates couldn't buy
 ** INTERNET: jca@pnet01.cts.com            | it, but he could rent it.  :)
 ** UUCP    : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca
 **--------------------------------------------------------------------------*
 */