On 07/08/2016 14:52, Gerrit Heitsch wrote: > > I read somewhere, that the PLA was used to allow starting the PCB > design before all the logic was ready. With the PLA you could make the > PCB and have a 28pin socket waiting for the guys who did the logic. That sounds wrong. Putting the logic on the mother board would take too much room and cost too much. The choice for someone like commodore, making mass market machines, is between a programmable part (like a PLA or PROM) or a custom mask. For development speed you would use a PLA, for cost reduction you would use a custom mask. The c64 started with an 82S100, which you could buy blank and then burn the logic into. Later on they did their own mask programmable clone, so they could take the existing logic and churn out a cheaper replacement. New designs could be prototyped with an actual PLA and then turned into a custom mask in a very short time. http://skoe.de/docs/c64-dissected/pla/c64_pla_dissected_a4ss.pdf Message was sent through the cbm-hackers mailing listReceived on 2016-08-07 16:00:02
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