instruction that sets the I (interrupt disable) flag, preventing IRQs from interrupting the code.
- Function: 1 => I
- Updates flags: . . . . . I . .
- Opcode number: impl $78
Caution: Do not confuse this with the sti instruction of x86, which does the exact opposite.
As opposed to: CLI
See also: 6502 instructions | 6502 addressing modes