Int 17H [PC] [AT] [PS/2] Function 01H Initialize printer port

Initializes the specified parallel printer interface port and returns its status.

Call with:

AH = 01H

DX = printer number (0 = LPT1, 1 = LPT2, 2 = LPT3)

Returns:

AH = status (see Int 17H Function 00H)