     $DE01/56833/SWIFTLINK+1:   Status Register

     Read:

       +-------+--------------------------------------------------------+
       | Bit 7 |   Interrupt Flag: 1 = Interrupt caused by SwiftLink    |
       | Bit 6 |   Carrier Detect: 1 = Carrier present                  |
       | Bit 5 |   DSR:            1 = High, 0 = Low                    |
       | Bit 4 |   Transmit Flag:  1 = Ready to get next Byte to        |
       |       |                       transmit in Data Register        |
       |       |                   0 = Chip currently sending Byte      |
       | Bit 3 |   Receive Flag:   1 = Byte received in Data Register   |
       |       |                   0 = Nothing received                 |
       | Bit 2 |   Overrun:        1 = Overrun occured (*)              |
       | Bit 1 |   Frame Error:    1 = Frame Error occured (*)          |
       | Bit 0 |   Parity Error:   1 = Parity Error occured (*)         |
       +-------+--------------------------------------------------------+

        (*) = Self-Clearing when read

     Write:
             Any write access will reset SwiftLink.