any building 6800 sbc's out there?

Tom Watson tsw-cc at johana.com
Wed Jun 18 12:24:32 CDT 2008


From: "Chris M" <chrism3667 at yahoo.com>
Sent: Sunday, June 15, 2008 8:26 PM
To: "General Discussion: On-Topic and Off-Topic Posts" 
<cctalk at classiccmp.org>
Subject: any building 6800 sbc's out there?

> just curious. When I started piddling around with this
> stuff in the late 80's I guess, that was one of the
> chips I intended to use as the basis for probably a
> small breadboarded computer. Never got around to it.
> But I did *swipe* a coco off of a friend and played
> with that for a spell (6809 based). Close enough! :)

Oh, 6800 stuff.  Brings back many old memories.  When the 6800 was released
back in 1975 (+- 1 year) I had the great idea to build a ham radio repeater
controller.  In the process I ended up doing a bunch more.  Eventually we had a
bunch of "cards" that used 44 pin edge connectors (look, it is what I had at
work) and it worked out quite well.  After the repeater project, I did some
work in testing Qume printers (you remember the Daisy Wheel things) and ended
up writing a small operating system using single density minifloppies and a
WD1771 controller chip (much better than discrete hardware!!).  The data rate
was slow enough (64 us/byte) that I could get away with having the data use the
non-maskable interrupt to transfer data.  Somewhere I've got some of the
hardware from that era.  The boxes could be maxed out at over 60k bytes.  One
of the 'projects' I ended up doing was the basis of a company I worked at from
'78 thru '83.  One interesting thing was that GM had a special chip made that
plugged into a 6800 socket, and ran 6801 code at 6801 cycle times (about 20%
faster!).  We got a couple and the system I've got in the garage still has it
working.

Never did get into S100/CP-M stuff.  Oh, well.


      



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