[comp.os.minix] VGA/EGA BUGS

walls@attctc.Dallas.TX.US (Monty Walls) (02/11/90)

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	A couple weeks ago someone was asking about a problem with using
a VGA card with minix.  I had the same problem when I installed my ATI VGA
card.  When I booted minix it would hang immediately.  This is caused
by the VGA card generating an interrupt on IRQ 2 every 60th of a second
(vertical retrace interrupt).  This can also happen with some EGA cards
(I think).  To stop this just don't enable IRQ 2.


-Monty Walls


Monty Walls
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jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (02/11/90)

In article <11400@attctc.Dallas.TX.US> walls@attctc.Dallas.TX.US (Monty Walls) writes:
>	A couple weeks ago someone was asking about a problem with using
>a VGA card with minix.  I had the same problem when I installed my ATI VGA
>card.  When I booted minix it would hang immediately.  This is caused
>by the VGA card generating an interrupt on IRQ 2 every 60th of a second
>(vertical retrace interrupt).  This can also happen with some EGA cards
>(I think).  To stop this just don't enable IRQ 2.

I have an ATI VGA Wonder card, and had a similar problem when trying to
boot Minix 1.2.   However, I traced the source of the interrupt to the
mouse port on the card.  In order to get Minix to boot, I had to disable
the mouse port from MS DOS, and then reboot.

Minix 1.3 did not give this problem, presumably because the interrupt
is handled by a stub routine.

-- 
John Dudeck                           "You want to read the code closely..." 
jdudeck@Polyslo.CalPoly.Edu             -- C. Staley, in OS course, teaching 
ESL: 62013975 Tel: 805-545-9549          Tanenbaum's MINIX operating system.