Int 14 Fn 05  - Digiboard Digichannel Pc/x* - Change Protocol              [S]

   AH = 05h
   AL = protocol (see #0261)
   BH = new XOFF character (00h = current)
   BL = new XON character (00h = current)
   DX = port number (00h-03h) (04h-43h for XAPCM232.SYS)

Return: AH = status
       00h successful
       FFh error

See Also: AH=04h"Digiboard"

Bitfields for Digiboard protocol:
Bit(s) Description (Table 0261)
 7-4   unused
 3 RTS/CTS
 2 DSR
 1,0   XON/XOFF