[comp.os.minix] MINIX on Hyundai 386SX AT-clone

cflatter@zia.aoc.nrao.edu (Chris Flatters) (06/22/91)

The problem:
   MINIX refuses to boot from the distribution floppy.  The copyright
   message appears but the drive heads then get driven into the stops
   and back again.  An error message a reboot is attempted.  This
   repeats until I hit the reset switch & pull the floppy out.

Hypothesis:
   The Hyundai Super 386S is not as compatible with the IBM PC/AT as
   I thought.  The floppy controller presumably differs from the one
   bootblok expects.

Possible Solution 1:
   Make a copy of the generic (BIOS-based) boot floppy (#3) & apply a 
   binary patch to  the boot sector.  This should get me to the stage
   where I can patch bootblok.s and the floppy drivers & build a new
   boot floppy.  The obvious problem is that I don't know what the
   necessary patches out there are.  I don't even know what kind of
   controller the Hyundai is using.  Does anyone out there have any
   more information?

Possible Solution 2:
   Buy an add-in floppy controller (making sure that it has the right
   kind of chip).  The problem here is that I don't know if MINIX
   will boot off any floppy other than A:.  Does it?

Default Solution:
   Put MINIX back in the box, return it to Prentice-Hall & beg for
   my money back.

Can anybody think of something that I haven't (buying a new PC is not
a realistic option).


	Chris Flatters
	cflatter@nrao.edu

-- 
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Chris Flatters                  |  cflatter@nrao.edu
AIPS Scientific Programmer      |
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u8acb@ohm.york.ac.uk (+Alex Barclay) (06/22/91)

In <1991Jun21.192618.3446@zia.aoc.nrao.edu> cflatter@zia.aoc.nrao.edu (Chris Flatters) writes:

>The problem:
>   MINIX refuses to boot from the distribution floppy.  The copyright
>   message appears but the drive heads then get driven into the stops
>   and back again.  An error message a reboot is attempted.  This
>   repeats until I hit the reset switch & pull the floppy out.

Try turning the clock speed down. My machine, a 386SX running at 16 or 8MHz
won't boot Minix 1.2 unless the clock is running aat 8MHz. The problem
appears to be in kernel/floppy.c but I need to work out the drive timings
yet to fix the problem.

		Good Luck,
			Alex.
--
She stares at the screen, At the little words of green,
Tries to remember what to do next.
acb5@vaxa.york.ac.uk (Main) or u8acb@ohm.york.ac.uk (Dept)

evans@syd.dit.CSIRO.AU (Bruce.Evans) (06/27/91)

In article <1991Jun22.132009.4070@ohm.york.ac.uk> u8acb@ohm.york.ac.uk (+Alex Barclay) writes:
>In <1991Jun21.192618.3446@zia.aoc.nrao.edu> cflatter@zia.aoc.nrao.edu (Chris Flatters) writes:
>
>>The problem:
>>   MINIX refuses to boot from the distribution floppy.  The copyright
>>   message appears but the drive heads then get driven into the stops
>>   and back again.  An error message a reboot is attempted.  This
>>   repeats until I hit the reset switch & pull the floppy out.
>
>Try turning the clock speed down. My machine, a 386SX running at 16 or 8MHz
>won't boot Minix 1.2 unless the clock is running aat 8MHz. The problem

The main timing problem in the floppy driver was fixed in 1.5.

What size is the disribution floppy? 1.2M works best. Any other size may
run into various unportabilities in the boot program.
-- 
Bruce Evans		evans@syd.dit.csiro.au

cflatter@zia.aoc.nrao.edu (Chris Flatters) (06/30/91)

> In article <1991Jun22.132009.4070@ohm.york.ac.uk> u8acb@ohm.york.ac.uk (+Alex Barclay) writes:
>>In <1991Jun21.192618.3446@zia.aoc.nrao.edu> cflatter@zia.aoc.nrao.edu (Chris Flatters) writes:
>>
>>>The problem:
>>>   MINIX refuses to boot from the distribution floppy.  The copyright
>>>   message appears but the drive heads then get driven into the stops
>>>   and back again.  An error message a reboot is attempted.  This
>>>   repeats until I hit the reset switch & pull the floppy out.
>>
>>Try turning the clock speed down. My machine, a 386SX running at 16 or 8MHz
>>won't boot Minix 1.2 unless the clock is running aat 8MHz. The problem
>
> The main timing problem in the floppy driver was fixed in 1.5.
>
> What size is the disribution floppy? 1.2M works best. Any other size may
> run into various unportabilities in the boot program.

The problem was indeed the size of the floppy: PH distribute MINIX on
360k floppies.  However, by turning the clock down to 8 MHz I could get
MINIX to boot.  After that it was an easy job to build at 1.2M boot disk.

> -- 
> Bruce Evans		evans@syd.dit.csiro.au
-- 
======================================================================
Chris Flatters                  |  cflatter@nrao.edu
AIPS Scientific Programmer      |
======================================================================