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From: srh@.uucp (Steve Harmon)
Newsgroups: comp.sys.tandy
Subject: 16B/6000 MMUs
Message-ID: <1991May21.142456.27022@tridom.com>
Date: 21 May 91 14:24:56 GMT
Sender: srh@tridom.com (Steve Harmon)
Distribution: na
Organization: AT&T Tridom; Marietta, Georgia
Lines: 30

In article <5766@mindlink.bc.ca>, nanook@eskimo.celestial.com (Robert Dinse) writes:
>	[request for memory upgrade info deleted]
>
>     In order to do this you need an MMU upgrade. Stock the MMU can only
>address 1 megabyte of memory. Last time I got a price quote from Tandy
>it was around $300 if memory serves. I've got a couple of CPU boards with
>a custom MMU (that doesn't have a PAL chip - courtesy of design work done
>by Monty Schmidt) that works ok with 2-megs but not more than that. I am
>speculating that it's a fan-out problem.

    I've been meaning to post something about MMUs for a while so I guess
now is as good a time as any.  Some years ago I designed, manufactured and
sold MMUs for the 16B/6000.  This was a year or so before Tandy released
their MMU.  If anyone is interested in the technical info required to build
their own MMU then send me some email and I'll provide it for you.  The
unit is pretty simple to build (in fact the prototype was built on a piece
of perf board from RS :-) and only contains 5 parts.  This is probably not
a very good project for people with no working knowledge of digital electronics
especially since it requires modifying the CPU board.

    Anyway, anyone who is interested is welcome to send me some email.
Also, I believe that I still have 40-50 blank MMU boards somewhere if anyone
is interested (the info is free, the boards I'll probably charge for).

--
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