$20/32:   Drive 0 status (disk and step motor)

   +-------+------------------------------------------------------+
   | Bit 7 | Disk drive ready: 1 = No, 0 = Yes                    |
   | Bit 6 | ReaD/Write head moving: 1 = Yes, 0= No               |
   | Bit 5 | Motor on: 1 = Yes, 0 = No                            |
   | Bit 4 | Switch off motor: 1 = Yes, 0 = No                    |
   +-------+------------------------------------------------------+