Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!rice!uw-beaver!ubc-cs!alberta!atha!rwa
From: rwa@cs.AthabascaU.CA (Ross Alexander)
Newsgroups: comp.sys.atari.st
Subject: Re: UNIX clone from Mark Williams Co.
Summary: I think they did, but it wasn't released...
Message-ID: <1786@aurora.AthabascaU.CA>
Date: 29 Mar 90 18:29:06 GMT
References: <1990Mar26.143622.18337@pmsmam.uucp> <1847@bdt.UUCP> <3787@tahoe.unr.edu>
Organization: Athabasca University
Lines: 44

mikew@wheeler.wrcr.unr.edu (Mike Whitbeck) writes:
> cs161fca@sdcc10.ucsd.edu writes:
> > made the Mark William C for the ST) for their product "Coherent", a
	[...]
> > Does anyone know if that will be ported to the ST?
> Presumably they would port it to the ST if possible. 

A long time ago (at least 18 months) I remember Daniel Glasser, at
that time an MWC employee [I believe; corrections solicited]
mentioning that MWC had ported Coherent to a slightly-modified 1040.
The mods involved building a little MMU (the chip Atari calls an MMU
is more of a memory controller than a memory _manager_) from MSI logic
to enforce interprocess memory protection and to do dynamic relocation
(i.e., every user task believes it has memory starting @ 0 or some
other small fixed value, and can't write to system or other process
memory spaces).

I believe they decided that the product wasn't marketable, which is
sad since Minix-ST has shown how much hackers would like a small Un*x
clone for the ST platform.  Perhaps we could persuade MWC to release
schematics and/or a board layout for their MMU?  I would gladly pay
two hundred dollars or so for one, if it gave me (say) base-and-limit
registers for User I&D plus Super I&D - four base-and-limit pairs
would be adequate.  Another one or two or three to handle DMA accesses
and/or interrupt vector fetches and/or video accesses would be nice
but hardly nescessary.

Daniel, are you still out there?  Any chance of this?  I'd settle for
just a schematic.  This would be lots of fun even without Coherent;
MMU support could be stuck into Minix without too-too major surgery
I think.  It would be a lot of fun.

BTW, I don't mind carving on my ST because I don't really care whether
it runs or not.  I am moving to a used Sun 3/50, and taking my SCSI
peripherals with me, Uncle Jack can stick that in his "TTx" pipe and
smoke it :-P.  The TTx is two years late and 50% too slow, 16 MHz
indeed.  If Atari had just stuck to its knitting (designing, building,
and marketing _computers_) instead of fiddling around in the LBO arena
and getting *burned*, both they and we would be far better off IMHO.
But hey, who ever listens to the customers?  With luck, maybe MWC?!

-- 
--
Ross Alexander    (403) 675 6311    rwa@aungbad.AthabascaU.CA    VE6PDQ