Int 14 Fn 02  - Serial - Read Character From Port                          [S]

   AH = 02h
   AL = 00h (ArtiCom)
   DX = port number (00h-03h (04h-43h for Digiboard XAPCM232.SYS))

Return: AH = line status (see AH=03h)
   AL = received character if AH bit 7 clear

Notes: will timeout if DSR is not asserted, even if function 03h returns
     data ready
   various network and serial-port drivers support the standard BIOS
     functions with interrupt-driven I/O instead of the BIOS's polled I/O
   the 04/08/93 Compaq system ROM uses only the low two bits of DX

See Also: AH=01h,AH=02h"FOSSIL",AH=84h,AH=FCh