DEC (thing)

1. Digital Equipment Corporation, a division of Compaq Computer Corp, a division of Hewlett-Packard.

2. A 6502 instruction that subtracts 1 from a memory location.

• Function: N--
• Updates flags: S . . . . . Z .
• Opcode numbers:

  dp    $C6
  abs   $CE
  dp,x  $D6
  a,x   $DE
  

Don't forget to add 2 cycles, as DEC is a read-modify-write instruction.

Similar: DEX | DEY | INC | INX | INY
See also: 6502 instructions | 6502 addressing modes