STX                    STX Store index X in memory                    STX

  Operation: X -> M                                     N V - B D I Z C
                                                        . . . . . . . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Zero Page     |   STX $FF             |   $86   |    2    |    3     |
  |  Zero Page,Y   |   STX $FF,Y           |   $96   |    2    |    4     |
  |  Absolute      |   STX $FFFF           |   $8E   |    3    |    4     |
  +----------------+-----------------------+---------+---------+----------+