$D0B2/53426/SCPU+66:   Hardware Register-/System Flag

   +-------+--------------------------------------------------------+
   | Bit 7 |   Hardware Register Enable Flag: 1 = Enabled           |
   | Bit 6 |   System 1 MHz Flag: 1 = Enabled                       |
   +-------+--------------------------------------------------------+

     This register is read only with hardware registers disabled,
     Read/Write with hardware registers enabled, write access reserved
     for system only.