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What is the purpose of the M1 pin on a Z80

As an addition to the other answers: The Z80 used the combination of M1 and IORQ to signal interrupt acknowledge. Zilog calls this a "special M1 cycle." BTW, just the CMOS CPU series by ...
the busybee's user avatar
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16 votes
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What is the purpose of the M1 pin on a Z80

Besides the literal purpose of knowing when an instruction is being fetched it was in practice used as a timing hint. Most reads and writes on a Z80 take three cycles and whatever is on the other side ...
Tommy's user avatar
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2 votes

What is the purpose of the M1 pin on a Z80

One thing I noticed is pin 27, called "M1", which is used to indicate when the "Z80 is fetching next instruction from memory". That's what it does. I'm left wondering what the ...
Raffzahn's user avatar
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