Notably, the Motorola 6800 has decrement and increment for the accumulator, both of them. It also features an indexed address mode that is somewhat reverse to h

Notably, the Motorola 6800 has decrement and increment for the accumulator, both of them. It also features an indexed address mode that is somewhat reverse to how the 6502 does it: there's only one index register (X), but this is of 16-bit length and a single-byte operand is added to this. So, while not exactly a zeropage address, with a bit of courage for self-modification we get there… The 6502 did intentionally away with quite a number of features, but, as it had since become evident that it was a computer CPU, WDC added (back) for the CMOS version some of what was kind of missing for this application. (The thing I'm probably missing most on the 6502 is a sequential-shift or barrel-shifter, shifting/rotating by multiple bit positions at once. This would be so great for games, graphics, encoding and decoding… Sophie Wilson had the wisdom to opt this into the ARM architecture.)