$D0B4/53428/SCPU+68:   Optimization Mode Flags

   +----------+---------------------------------------------------+
   | Bits 7+6 |   00 = GEOS Optimization Enabled                  |                                     |
   |          |   01 = VIC Bank 01 Optimization Enabled           |
   |          |   10 = BASIC Optimization Enabled                 |
   |          |   11 = No Optimization                            |
   +----------+---------------------------------------------------+

     This register is read only with hardware registers disabled,
     Read/Write with hardware registers enabled.