Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

Heh, yeah I still remember 6502 opcodes... 4C xx xx is jmp absolute, 20 xx xx is jsr (jump subroutine) absolute, A9 xx xx is load accumulator absolute, 8D store accumulator, 60 is rts... I could go on.

Typing shit in to the hex monitor for a few years will do that :)



A9 xx xx is load accumulator absolute

Make that A9 xx; The 6502 accumulator is 8 bits.


Thanks for the correction, you're right A9 is load immediate I was mixing it up with AD xx xx which follows as 8D is the equivalent store.

I wasn't saying that the accumulator was 16 bit though, rather that the load is from an absolute 16 bit address.




Consider applying for YC's Summer 2026 batch! Applications are open till May 4

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: