jhamby on Nostr: 65C816 is highly elegant because it fills up nearly all 256 single-byte opcodes with ...

65C816 is highly elegant because it fills up nearly all 256 single-byte opcodes with something useful, and since there are so few registers, everything is very orthogonal. It has a great mix of addressing modes as well. Most importantly, the return stack can now be up to 64K, not limited to 256 bytes starting at 0x0100. You can move around "zero page" as well.

But it's very "modal". There's a bit for 8-bit or 16-bit accumulator, a bit for 8 or 16-bit X and Y registers, and for 24-bit addresses.