Int 14 Fn 05  - Pc-mos/386 V5.01 $serial.sys V5.04 - Change Port Protocol  [S]

   AH = 05h
   AL = new port protocol (see #0262)
   BH = new XOFF character
   BL = new XON character
   DX = port number

Return: AH = FFh if invalid protocol

See Also: AH=00h,AH=04h"SERIAL",AH=06h"PC-MOS"

Bitfields for PC-MOS/386 serial port protocol:
Bit(s) Description (Table 0262)
 7 set to enable/disable CD monitoring, clear to set protocol
---bit 7 set---
 4 CD monitoring enabled
 5 automatic restart enabled
---bit 7 clear---
 0 receive XON/XOFF
 1 transmit XON/XOFF
 2 DTR/DSR
 3 RTS/CTS