SLO           SLO ASL memory, ORA accu, result into accu              SLO

                                                        N V - B D I Z C
  Operation:  A <- (M << 1) \/ A                        / . . . . . / /

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Zero Page     |   SLO $FF             |   $07   |    2    |    5     |
  |  Zero Page,X   |   SLO $FF,X           |   $17   |    2    |    6     |
  |  Absolute      |   SLO $FFFF           |   $0F   |    3    |    6     |
  |  Absolute,X    |   SLO $FFFF,X         |   $1F   |    3    |    7     |
  |  Absolute,Y    |   SLO $FFFF,Y         |   $1B   |    3    |    7     |
  |  (Indirect,X)  |   SLO ($FF,X)         |   $03   |    2    |    8     |
  |  (Indirect),Y  |   SLO ($FF),Y         |   $13   |    2    |    8     |
  +----------------+-----------------------+---------+---------+----------+
  * Add 1 if page boundary is crossed.

  Also known as ASO.