instruction that stores register A at a given memory location.
- Function: A => N
- Updates flags: none
- Opcode numbers:
You're probably wondering what happened to instruction $89. Well, it's a two-byte NOP that's faster (2 cycles) than BIT dp (3 cycles). If you're NOPping out code on older 6502s (not the CMOS parts), use $89 for all bytes except the last, which should be $EA (the normal 6502 NOP).
Similar: STX | STY
See also: 6502 instructions | 6502 addressing modes