      WDM                 WDM Reserved for Future Expansion                 WDM

     65816 only!
                                                            N V M X D I Z C
      Operation:  At the moment treated like NOP.           . . . . . . . .

      +----------------+-----------------------+---------+---------+----------+
      | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
      +----------------+-----------------------+---------+---------+----------+
      | Immediate      |   WDM #$FF            |   $42   |    2    |     2    |
      +----------------+-----------------------+---------+---------+----------+
      WDM is the first byte of a multi-byte instruction set to be built in future
      versions of the processor. This instruction should NOT be used by now.
      (WDM -> William D. Mensch jr., 65816 designer)