+-+-+-+-+-+-+-+-+
                             |7|6|5|4|3|2|1|0|
                             +-+-+-+-+-+-+-+-+
                              | | | | | | | |
                              | | | | | | | |
                              | | | | | | | |
                              | | | | | | | |
           PARITY OPTIONS ----+-+-+ | | | | +----- HANDSHAKE
 +---+---+---+---------------------+| | | |
 |BIT|BIT|BIT|     OPERATIONS      || | | |        0 - 3-LINE
 | 7 | 6 | 5 |                     || | | |        1 - X-LINE
 +---+---+---+---------------------+| | | |
 | - | - | 0 |PARITY DISABLED, NONE|| | | |
 |   |   |   |GENERATED/RECEIVED   || | | |
 +---+---+---+---------------------+| | | +------- UNUSED
 | 0 | 0 | 1 |ODD PARITY           || | +--------- UNUSED
 |   |   |   |RECEIVER/TRANSMITTER || +----------- UNUSED
 +---+---+---+---------------------+|
 | 0 | 1 | 1 |EVEN PARITY          ||
 |   |   |   |RECEIVER/TRANSMITTER |+------------- DUPLEX
 +---+---+---+---------------------+
 | 1 | 0 | 1 |MARK TRANSMITTED     |               0 - FULL DUPLEX
 |   |   |   |PARITY CHECK DISABLED|               1 - HALF DUPLEX
 +---+---+---+---------------------+
 | 1 | 1 | 1 |SPACE TRANSMITTED    |
 |   |   |   |PARITY CHECK DISABLED|
 +---+---+---+---------------------+

                     Figure 6-2. Command Register Map.

The formulas above are based on the fact that:

system frequency	= 1.02273E6 NTSC (North American TV standard)
	= 0.98525E6 PAL (U.K. and most European TV standard)

<command register>- Is a single byte character (see Figure 6-2, Command Register Map) that defines other terminal parameters. This character is NOT required.