DEQ                   DEQ Decrement 32bit memory by one                 DEQ

  Operation:  Q <- Q - 1 or M <- M - 1               N V - B D I Z C
                                                        / . . . . . / .

 4510 Versions:

  +----------------+----------------------+-----------+---------+----------+
  | Addressing Mode|Assembly Language Form|  OP CODE  |No. Bytes|No. Cycles|
  +----------------+----------------------+-----------+---------+----------+
  | Q Register     |   DEQ                |$42 $42 $3A|    3    |    3     |
  | ZeroPage Quad  |   DEQ $FF            |$42 $42 $C6|    4    |   12dmr  |
  | Absolute Quad  |   DEQ $FFFF          |$42 $42 $CE|    5    |   13dmr  |
  |ZeroPage Quad,X |   DEQ $FF,X          |$42 $42 $D6|    4    |   12dmpr |
  |Absolute Quad,X |   DEQ $FFFF,X        |$42 $42 $DE|    5    |   13dmpr |
  +----------------+----------------------+-----------+---------+----------+
  d Sub 1 if CPU is at 3.5 MHz
  m Sub non-bus cycles when at 40 MHz
  p Add 1 if page boundary is crossed.
  r Add 1 if clock speed is at 40 MHz