Z-80 M1?

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Wed Mar 31 08:39:07 1999

On Wed, 31 Mar 1999, Arfon Gryffydd wrote:

> I have never really understood the purpose of the M1 pin or cycle. Can
> anyone in simple terms explain it's purpose?
>

First, your linux sig line is kewl but over a teknet link editing it off
a reply is a royal PITA!

M1 signals the start of an instruction fetch or an interrupt cycle start.
It's machine status to differentiate a opcode fetch from a data read or
write. it serves other uses especially with the Z80 periperal chips.

Allison
Received on Wed Mar 31 1999 - 08:39:07 BST