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Re: 65C816 adapter for 6502 computers (aka Apple II)



Bryan Parkoff wrote:
Ouch!!
    I am sorry to state.  Unfortunately, 65816 CPU will NOT WORK on Apple
II+ nor Apple //e because 65816 CPU's and 6502 CPU's timing are not EXACT
the same.  They have different nanosecond measurement.  For example, 6502
CPU requires 400 ns to run while 65816 CPU runs 250 ns (I can't remember
exactly.)
    "Understanding an Apple //e" manual stated that someone tried to plug
65C02 CPU into Apple II+, but very several instructions work while often it
crashes at all times.

You might be interested in this site
http://home.hccnet.nl/g.baltissen/02to816.htm
I've built and used this adapter and it works quite well in a IIe
or II+.

Jim Sather did limited experiments with a few different 65C02 in the
II+. He certainly didn't try them all.
A couple of 65C02 that I've used for years in the II+ are the
GTE G65SC02P-1 and the R65C02

Wayne