>Hmm. Interesting. That's early 1980s, if not late 1970s, correct?
I have installed in my Altair, a Compu/Time CT-102 real-time-clock
board which was purchased in 1979. This board supports a battery
backup option.
This is basically a "digital clock" chip with BCD outputs (intended to
drive BCD to 7-segment decoders) on an S-100 board. The fact that it
is a chip intended for a clock display gives rise to certain odd
characteristics:
- Certain leading digits read 'F' instead of '0' for a zero value - this
is because 'F' == Blank on the 7-segment decoder.
- To set the time, the software has to "hold down" Fast and Slow time
set buttons, and watch the time value scroll by until the desired
setting is reached - just the way a human would set a digital clock
from that era.
Photos of this card and scans if it's documentation are available in
the Altair section on my site.
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
Received on Thu Jul 29 2004 - 11:37:26 BST