INT 17,1 - Initialize Printer Port

AH = 01

DX = printer port to initialize (0-2)

on return:

AH = status, see ~INT 17,STATUS~

- initializes printer port and returns status

- outputs characters 0x08 and 0x0C to printer port which

reset ~Epson~ and IBM printers, but may produce undesirable

effects on other printers