     $D0BC/53433/SCPU+76:   DOS Extension-/RAMLink Hardware Reg. Flag

       +-------+--------------------------------------------------------+
       | Bit 7 |   DOS Extension Mode Flag: 1 = Enabled                 |
       | Bit 6 |   RAMLink Hardware Registers Flag: 1 = Enabled         |
       +-------+--------------------------------------------------------+

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