Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!udel!gatech!mcnc!ecsvax!agb
From: agb@ecsvax.UUCP (Alan Bishop)
Newsgroups: comp.os.minix
Subject: Re: Question about Minix port
Message-ID: <4526@ecsvax.UUCP>
Date: 29 Jan 88 23:36:51 GMT
References: <1059@louie.udel.EDU> <1838@botter.cs.vu.nl>
Reply-To: agb@ecsvax.UUCP (Alan Bishop)
Organization: NCSU (Student)
Lines: 21

In article <1838@botter.cs.vu.nl> ast@cs.vu.nl (Andy Tanenbaum) writes:
>It will certainly cost something, but I don't think it will be even a factor
>of two.  Still, the only way to find out is to do it.  It should be very hard.
>Just replace floppy.c with a call to an assembly code routine to invoke the
>BIOS.  Be careful about low core.  Some BIOS ROMs do funny things with
>low core, and MINIX lives at 1536.  In theory, 1024 to 1535 is yours.
>If you write the code, measure it and tell us.

There is code that uses the BIOS for the floppy and wini drivers in the
patches to get MINIX running on the PS/2.  There is also a BIOS wini driver
in the Microsoft C patches.  

However, I can't comment on how much speed loss there is, since the only
machine I've used these on extensively is a Model 60 PS/2, and I don't have
anything to compare it with.

With any BIOSes later than average-age ATs, the BIOS has hooks that allow
you to trap it every time it's getting ready to go into a wait-state.  I
haven't gotten around to adding those on the PS/2.

alan