6 Feb
2007
6 Feb
'07
12:49 p.m.
I guess this could be said about a lot of units, but
a coco in particular seems to be a pretty good way of
studying computer hardware initially. The 6800 was
fairly commonly used in sbc's back in those days, and
the 6809 is just a step up from that. I can't say
The 6809 is one of the best of the 8 bit CPUs IMHO.
The CoCo is not a bad machine either. If you're interested in hardware,
then the CoCo 1 or 2 are the machines to look for becuase they're all
standard chips (the design was based on a Motorola application note
covering the 6809, 6883 (SAM) and 6847 (VDG) chips, I believe). The CoCo
3 is a much nicer machine to use (80 column text display, lower case
text, beter grpahics, etc), but the interesting stuff is in a custom chip
called GIME (Grpahics Interruopts, Memory Enhansments IIRC).
But at lest you could get offiical service manuals and schematics, and
there were unofficial commented disassemblies of the ROMs out there.
Before the free unices for PCs, a CoOo was probably the cheapest way to
run a multi-user OS (OS-9). I certianly enjoyed it.
-tony