On 11/04/2017 08:45 PM, Michał Pleban wrote: > A. Fachat wrote: > >> The easiest way to do this is probably hook up two register and a small >> gal to the databus mainly and the sync, r/-w phi2 and prob some more >> signals. Also a 15bit compare on the address bus. >> >> The gal would monitor the executed opcodes using the sync signal and on >> the right opcode and the right cycle would switch the register values. > > My thoughts exactly. For the 15 bit compare, I would probably prefer to > use something like 74LS25, no need to waste PLD pins on something this > trivial. 15 Bit compare? Meaning checking if all adress bits except A0 are zero? Shouldn't that be possible with just 15 diodes that have their cathodes connected together and their anodes connected to the adress lines? Might need a resistor as a pulldown. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2017-11-04 21:00:02
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