$DE07/56839/TURBO232+7:   Enhanced-Speed Register

 Turbo232 only!

   +----------+---------------------------------------------------+
   | Bit  7-3 |   Unused                                          |
   | Bit  2   |   Mode Bit (read only): 1 = Bits 0-3 of $DE03 are |
   |          |   cleared and enhaced speed is enabled            |
   | Bits 1-0 |   Enhanced Baud Rate (read only if Mode Bit = 0): |
   |          |              00 = 230400 Bd       10 = 57600 Bd   |
   |          |              01 = 115200 Bd                       |
   |          |              11 = reserved for future expansions  |
   +----------+---------------------------------------------------+