Int 14 Fn 22  - Pc-mos/386 V5.01 $serial.sys V5.04 - Receive Character, W  [S]

   AH = 22h
   DX = port number
   SI = timeout in timer ticks (0000h = default)

Return: AH = port status (see also #0230 at AH=03h)
        bit 7 = 1 indicates time-out
   AL = character received
Program: PC-MOS/386 v5.01 is a multitasking, multiuser MS-DOS 5.0-compatible
     operating system by The Software Link, Inc.

See Also: AH=02h,AH=0Fh"Digiboard",AH=21h"PC-MOS"