19 Apr
2003
19 Apr
'03
7:42 a.m.
Getting on 20 years ago I built a 6809 based computer
from a
series running in the UK magazine "Electronics & Computing
Monthly", called the 77/68 system. This was based on the SWTP
stuff but was marketed through a company called Stirling
Microsystems in Baker Street, London. Does anyone else here
remember that system? ...
As I remember it, the 77/68 was published in the ACC newsletter (not in
E&CM) - the original was a rather neat design by Mike Lord on 8" square
PCBs.
I built a seriously extended one of these (which eventually "fissioned" into
two complete systems - connected by a homebrew network that was a sort of
very cheap slow ethernet). Some boards were from the original design -
others I designed and implemented myself ... most notably including a 6809
board (the original was a 6800) with the only technical data being a pin-out
and some other vague descriptions in a Byte article. It was a couple of
years of successful use before I discovered that I was feeding the clock in
through the "wrong" pin!
Amongst the peripherals that this system acquired was a large Calcomp
plotter surplus from the University mainframe.
Unfortunately most of the hardware and documents have now been recycled or
worse.
Andy