Re: 65c02 in ][+ problem

[david@uow.edu.au (David Wilson)]

Wayne Stewart <waynes@intergate.ca> writes:
>David Wilson wrote:
>> According to Jim Sather, only the Rockwell 65c02 will work in an Apple ][+.
>> The NCR/GTE part requires the data bus to be set up for longer than the Apple
>> ][+ does.

>Yes but he did mention that he did limited experiments with only 4 different
>chips.
>While one of them was a GTE, it was a 2 mhz version while the one I'm using is a
>1mhz chip that was made several years after he did his experiments. Were the specs
>tightened up in later production chips?

Don't know - but I would expect a 2MHz part (running at 1.02MHz) would have
better timing margins than a 1MHz part at the same speed. That is why the
Apple //e was shipped with 6502A parts - they cost only 25c more and had better
timing margins (see Understanding the Apple IIe page 4-6).
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia