On 05/30/2013 08:22 AM, Jim Brain wrote: > Speaking (writing) of bank registers, anyone know of a TTL option that > has a falling edge trigger? Yes, I can do an inverter, but would rather > not. Use case is VIC-20, which won't work on rising edge of Phi, > because not all of the data is valid on rising edge. The 74LS373 or 74LS573 does that. But it's a latch, not a register. They use it in the C64 to de-multiplex the VIC address so it can access the char ROM. Trigger is the falling edge of _RAS. Now you have to check if a latch works in your case. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2013-05-30 07:00:52
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