INT 61 - Banyan VINES - PRINTER CONTROL
        AX = 0005h
        DS:DX -> request block
Return: AX = status
            0000h successful
            0001h network software not installed or incompatible

Format of request block:
Offset  Size    Description
 00h    WORD    function
                0201h "endspool" all data for a print job has been sent
                0205h "getactive" get currently active printer port
 02h    WORD    number of active port (1-3)
 04h    WORD    ??? (0 for func 0201h, 3 for func 0205h)
 06h    WORD    0000h