15 Jul
2015
15 Jul
'15
11:24 a.m.
On 7/14/2015 7:36 PM, Jon Elson wrote:
On the system 360 CPUs, they did not use flip-flops
like we are used
to, today. They used latches ... Since these were discrete transistor
implementations, a real flip-flop was too expensive, but a latch could
be implemented in about 6 transistors, I think.
The 11/45 used TTL ICs, so real FFs were available in that technology,
although they may have used latches as well.
This confused me a bit, until I realized that you were using "latch" for what
I think of as 'SR flip-flop', and "flip-flop" for 'D and JK
flip-flops'.
Guess that shows how long ago I did hardware... :-)
To be a bit more detailed, on the 360's, were those latches 'simple' SR flops
(i.e. un-gated), or were they gated?
Noel