From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca>
I suspect this is because
1) All registers but the PC are 8 bit.
Total number of bits including storage for status were about 1/3
that of Z80 (208).
2) Instructions grouped into fewer internal states per
clock.
Yes, and instructions were simpler in construction. Some Z80
instructions like the block moves and searches (ex LDIR) and
a complete set of IO instuctions (not present on 6502) made
for a great difference in size and complexity of the instruction set.
I think a z80 instruction could have 17+ states where
a
6502 used up to 5 states.
Actually Z80 went as far as 22states.
Allison