18 Jun
2008
18 Jun
'08
8:36 a.m.
The C64 does
not use the 1st generation 6502, but rather a modified 8502
CPU with different electrical specifications, so I guess it was
explicitly designed to be able to drive its special C64 peripherals.
I don't recall ever seein "8502" anywhere, the actual number in there
being
6510, which has the onboard I/O port as being the major part of the
differences as far as I'm aware. I don't know about differences in drive
specifications and such. Nor do I have a clue as to where those 85xx numbers
came from, only that I ran into some of them in the later c64s being used
for CPU, SID, and VIC chips. Mostly though I have a lot of 6502s and 6522s
from 1541s, 6526s, and some small number of other parts. I'm not that
familiar with those parts from the programming side of things though. Nor do
I have any plans to support onboard video like the 64 did.