Int 14 Fn FF02  - IBM/yale Ebios Serial I/o - Buffered Read                [S]

   AX = FF02h
   CX = length
   DX = port (00h-03h)
   ES:BX -> buffer

Return: CX = number of characters read

See Also: AH=18h,AH=83h"COURIERS",AH=A5h"BAPI",AH=FCh