[comp.os.minix] Will Minix run on a Sota286/i?

ed@iitmax.IIT.EDU (Ed Federmeyer) (07/03/90)

I have sucessfully upgraded Minix to 1.5.10, and would like to use the
'286' mode...  I have a PC/XT clone with a Sota 286/i "speedup" board.  So
far, when I run DOS "system checkers" they all think it is a 286...  but when
I try to run Minix in the '286' mode, it hangs.  (8088 mode works like a charm
though...)  Does anyone else have one of these boards running Minix in the
'286' mode?  I kinda figure you need the Sota Memory/16 "expantion-expantion"
:-) board to make the XT look enough like an AT to use all the interrupts
and stuff, but I thought maybe I am just overlooking something.  Any ideas?

Thanks,  Ed Federmeyer  (ed@iitmax.iit.edu)  (sysed@iitVax.bitnet)
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petrilli@walt.cc.utexas.edu (Chris Petrilli) (07/03/90)

In article <3927@iitmax.IIT.EDU> ed@iitmax.iit.edu (Ed Federmeyer) writes:
>I have sucessfully upgraded Minix to 1.5.10, and would like to use the
>'286' mode...  I have a PC/XT clone with a Sota 286/i "speedup" board.  So
>far, when I run DOS "system checkers" they all think it is a 286...  but when
>I try to run Minix in the '286' mode, it hangs.  (8088 mode works like a charm
>though...)  Does anyone else have one of these boards running Minix in the
>'286' mode?  I kinda figure you need the Sota Memory/16 "expantion-expantion"
>:-) board to make the XT look enough like an AT to use all the interrupts
>and stuff, but I thought maybe I am just overlooking something.  Any ideas?
>

I beleive you have the right idea, but the problem stems from the fact that
Minix uses almost no BIOS calls (except for the beginning as I recall). 
I have a suspesion that the SOTA board, while compatible with DOS, cannot
handle the low-level bit-twidling that Minix does.

Another possibility is the fact that you are still using an xt controller 
(xt_wini.c), and the 286 version is linked with the AT version (at_wini.c),
you might try reversing this.

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des@musashi.wpd.sgi.com (Des Young) (07/05/90)

In article <33185@ut-emx.UUCP>, petrilli@walt.cc.utexas.edu (Chris Petrilli) writes:
> In article <3927@iitmax.IIT.EDU> ed@iitmax.iit.edu (Ed Federmeyer) writes:
> >I have sucessfully upgraded Minix to 1.5.10, and would like to use the
> >'286' mode...  I have a PC/XT clone with a Sota 286/i "speedup" board.  So
> >far, when I run DOS "system checkers" they all think it is a 286...  but when
> >I try to run Minix in the '286' mode, it hangs.  (8088 mode works like a charm

Actually, I think your problem is that Minix uses the AT BIOS. It is used
for two things, one is extended memory transfers, while the other is to
switch into protected mode. The latter is the really essential one.
You need to look at the AT BIOS and insert the equivalent into the Minix
assembly library in the kernel. I was going to do it, but I run 32000
Minix now :-), so could not be bothered with a brain-dead 286 architecture.
(But, if you fix it I would like a copy :-))

Cheers, Des.


Des Young.	des@musashi

colvin@portia.Stanford.EDU (Michael Colvin) (07/09/90)

The 286i memory board includes the AT BIOS.  I, too, have a 286i.  I'm wainting
to get the memory board before I install 1.5.10 on that one


Mike Colvin