Which Dec Emulation is the MOST useful and Versatile?
bhilpert at shaw.ca
Fri Oct 27 14:04:24 CDT 2017
On 2017-Oct-27, at 11:28 AM, Paul Koning via cctalk wrote:
> It helps to have a machine built with sane design principles. Things like RS flops that don't have both inputs active at the same time. And a properly clocked architecture. Neither of these properties holds for the CDC 6600...
True of a lot of 50s / 60s / even early-70s logic, designers took a lot of 'electronic shortcuts' to save components, capacitive coupling for instance being popular.
Flip flops with half-a dozen options of semantically different input types which could be combined in multiple, so every flip-flop in the system was unique with it's particular set of (sometimes many) input options.
One logic design I encountered had a type of logic element specifically intended (from what I could figure) to soak up glitches.
It could take in multiple inputs with edges occurring at slightly skewed times and ensured that only one slightly-delayed edge would be propagated out.
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