ocr: THE 8502 MICROPROCESSOR (Continued) 1 00 Phase 0 clock input. This is the dual speed system clock for the 128. 2 RDY Ready, TTL level input, used to DMA the 8502. The processor operates normally while RDY is high. When RDY makes a transition to the low state, the processor will finish the operation it is on, and any subsequent opera- tion if it is a write cycle. On the next occur- 315020 rence making of it read possible cycle to the tri-state processor the will processor hait, 8502 MICROPROCESSOR to gain complete access to the system bus. 3 IRO The Interrupt Request input is a request that the ...