On 21/07/2010 22:30, Dave McGuire wrote:
On 7/21/10 5:24 PM, Eric Smith wrote:
A
single-stepping circuit for a Z80 is pretty simple.
True, but it is not quite as
simple as hooking up a debounced pushbutton
to the clock, which was how I interpreted the OP's question.
Yes, I suppose you're right. It's much nicer (IMO) to do the full
trick by asserting /WAIT with /M1, a flip-flop, AND a debounced
pushbutton, though. Then you get true instruction stepping, rather than
cycle stepping.
Depends on what you want. I've used a debounced switch, and sometimes
it's more useful to step through the various T-states within
instructions, rather than stepping an instruction at a time. Other
times, it's just extra tedious.
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Pete Peter Turnbull
Network Manager
University of York