18 Jun
2008
18 Jun
'08
10:24 a.m.
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.