SHS                                                                   SHS

  Operation:  X <- (A) /\ (X), S <- (X)                 N V - B D I Z C
              M <- (X) /\ (PCH+1)                       . . . . . . . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Absolute,Y    |   SHS $FFFF,Y         |   $9B   |    3    |    5     |
  +----------------+-----------------------+---------+---------+----------+

  Also known as TAS.

  Warning: This opcode is said to be unstable!