Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mit-eddie!uw-beaver!cornell!batcomputer!rpi!crdgw1!ge-dab!peora!rtmvax!wbeebe
From: wbeebe@rtmvax.UUCP (Bill Beebe)
Newsgroups: comp.os.minix
Subject: Re: Bruce Evans' opus
Message-ID: <3032@rtmvax.UUCP>
Date: 1 Jun 89 01:23:30 GMT
References: <2570@ast.cs.vu.nl> <216@bilver.UUCP> <17779@mimsy.UUCP>
Reply-To: wbeebe@rtmvax.UUCP (Bill Beebe)
Organization: RTmVax Public Unix System, Orlando FL
Lines: 33

In article <17779@mimsy.UUCP> jds@mimsy.umd.edu (James da Silva) writes:

>I must be even more imcompetent (sic) than Dr. Tanenbaum, as I don't see
>your point at all.  Could you draw me another picture?
>
>Seriously, the fact is that it is tricky for a 32-bit kernel to support
>16-bit processes.  And out of the question for a 16-bit kernel to support
>32-bit processes.  So what choice do we have?  The 16-bit and 32-bit
[stuff deleted]
>Nit Pick: Bit 21 of the descriptor is not `O', it is `0', as in Undefined.
>
>Jaime

No, the incompetent boob is me, the guy who left his brain on idle while his
hands went wild on the keyboard. If I had thought about the the 16- vs
32-bit kernel problems I would have killed the comment, or at least put more
thought into it. The points I was trying to make are:

1) once you have 80286 protected mode, you can move up to the 80386 and
   use the code as-is, assuming that you have the same video, serial, and
   mass storage devices on an AT architecture machine. You will have to
   remain in 16-bit mode, and migration to 32-bit will be no trivial matter.
   But it is not impossible, and is in fact (at least to me) an inviting
   challenge.

2) it would be nice to have a teaching 32-bit Minix. Why can't we have some
   say-so in the process? Bruce Evan's work is so good, and Dr. Tanenbaum
   seemed to slam the door on that work and all it promises. I became very
   angry at the apparent tone of the message.

As for '0' vs 'O', I'm suprised I can type at all, considering my
coke-bottle bottom glasses. I'll try to keep my typos to a minimum, or at
least not make them in overly obvious areas.