INT 17 - Alloy NTNX, MW386 - SET DATA DRIVEN PRINT BREAK
        AH = 97h
        AL = mode
            00h NTNX compatibility
            02h MW386 v2+
                BX = logical device number
                    00h-03h = LPT1-LPT4
                    04h-07h = COM1-COM4
        CH,CL,DH = three character break sequence
        DL = subfunction
            00h set break string
            else reset break
Return: AL = status (see AH=81h)
Notes:  mode 00h affects only logical LPT1
        when the break string is encountered, the spool file will be closed and
          queued for printing automatically
        the break string is not permanently saved, and will be reset each time
          MW386 or the user is rebooted