4 Aug
2014
4 Aug
'14
3:40 p.m.
For those interested in early electronic calculator
architecture, the
reading in the Maintenance & Service manual is really interesting.
Yes... I found it interestign that this machien uses n pulses to represet
a digit n, not a bianry encoding. And that there is no full adder in the
machine, jsut counters.
Iv've noticed (not surpisingly0 that early electronic calculators tended
to follow the architecture of mechanical machines, essentially using
counters for everything and having dedicated registers/counters and
pathways between them. Later machines were more of the sort of
architecture we all know and love, a gneral-purpose processor with an
ALU, registers, etc, and firmware to cotnrol it and make it into a
calculator (look at the HP98x0 series, for example). The HP9100 is
somwehre in the mdddle, a sort-of processor + firmware architecture, but
with no real ALU.
-tony