Int 14 Fn 6F03  - Hp Vectra Ex-bios - "f14_get_buffer" - Read Data Into B  [S]

   AX = 6F03h
   CX = size of buffer
   DX = port number (0-3)
   ES:DI -> buffer for received characters

Return: AH = line status (see #0230)
   ---on error (AH bit 7 set)---
      AL = 00h
      ES:DI -> next byte to be transferred
   ---if successful---
      AL = last byte read
      ES:DI unchanged
   CX = number of bytes read
Desc:  read characters into the specified buffer until the buffer is filled
     or a timeout occurs

Notes: supported by original HP Vectra AT and by ES/QS/RS series Vectras
   polls the Data Set Ready modem status and Data Ready line status bits
     to determine when characters are available

See Also: AX=6F00h,AX=6F02h,AX=6F04h