INT 17 - PC Paint Plus 2.0 - PRINTER DRIVER
        AH = 20h
        AL = function number
            00h installation check
                Return: BX = driver version number (BH=major,BL=minor)
                        CH = ??? (00h)
                        CL = ???
                        DX = ??? (0100h)
                Note: also enables the remaining functions
            01h set ??? flag
            02h get information
                CL = subfunction
                    00h get printer type
                        Return: ES:DI -> ASCIZ printer name
                    01h get paper size
                        DX = size index
                        Return: ES:DI -> ASCIZ paper size description
                    02h get ???
                        Return: BX = ???
                    03h get printer information???
                        DX = ???
                        ES:BX -> buffer for ??? (min 134 bytes)
            03h ???
                ES:BX -> ???
            04h get ???
                Return: ES:DI -> ???
            05h advance printer to next page
                Note: also clears flag set by function 01h
            06h advance printer to next page and shut down
                Note:   also clears flag set by function 01h and disables
                          functions other than 00h
            07h not implemented, AX returned unchanged
        BL = printer number???
Return: AX = status
            0000h successful
            0001h invalid printer???
            0002h ???
            0003h invalid subfunction
            0005h driver disabled, must call function 00h first
            0009h unknown printer error
            000Bh printer not selected
            000Ch printer out of paper
            000Eh error while writing to serial printer
            000Fh ???
            0010h invalid function number
            0011h value out of range