1 Feb
2010
1 Feb
'10
12:02 p.m.
No... I spent many a year searching, too. I have the
manual, which I think
includes the schematic (if not, I got that separately), but I never did come
across the physical board.
You're going to hate me. I've got _2_ of them. One with the normal ROM
for the 40 column VDU card, the other with a ROM for the rare 80 column
VDU (and yes, I have that card too).
The curious Tiger used a 68B09 for I/O (along
with a Z80A for the main
processor and a 7220 graphics chip).
The HH machine? I've never seen a real one, but it sounded like an interesting
beast. Remember that there was a *lot* of in-house expertise
in 6502 development; the
Atom was almost a "System rack in a home computer box", just as the BBC was an
To the extent that the expansion bus was a System bus connector. You
could fit one System eurocard inside an Atom -- at least one of my Atoms
has the econet interface doen that way (another one of my Atoms has the
'proper' econet interface PCB plugged into the solder side of the mainboard).
The video ciorcuitry was very differnt, though. THe Atom used the 6847
VDG chip. The System VDU cards used 6845s, and in the case of the 40
column one, an SAA5050 teletext charactger geenrator ROM.
-tony