30 Nov
2001
30 Nov
'01
9:26 a.m.
Tony Duell wrote:
While I don't expect to find DTL,RTL or even TTL nowadays
you can still get the 7 segment filament displays.
http://www.sphere.bc.ca/test/nixies.html#catalog
--
Ben Franchuk --- Pre-historic Cpu's --
www.jetnet.ab.ca/users/bfranchuk/index.html
Tony Duell wrote:
rganised, and doubtless some of the
Sure, I've got all ten articles describing it. I think I posted rough
descriptions of the contents of each article to Classiccmp a couple of
years back.
It was a 4 function desktop calculator. Display was those 7 segment
filament displays (thin filaments forming the segments, mounted in an
evacuated 'bulb'). About 10 digits, I think. It displayed -ve numbers in
9's compliment notation (!).
The 'data path' was TTL ICs on plug-in cards. It was digit-serial, and
did multiplication/division by shifting by digits and then repeated
addition/subtraction for each digit.
The control section was a diode matrix ROM on a large piece of stripboard
in the bottom of the machine. Controlled by yet more TTL.
'PE', btw was the UK magazine 'Practical Electronics'.
-tony <snip,cut,rip>
[1] The PE Digical may be one of the first hobbyist calculators
(published 1972, all built from TTL chips), but it wasn't programmable.
Stick it on the list if you like.
Got more details???