NAME

lpt − parallel port interface for PC’s

SYNOPSIS

­bind -a #L[123] /dev
 ­/dev/lpt[123]data
­/dev/lpt[123]dlr
­/dev/lpt[123]pcr
­/dev/lpt[123]psr

DESCRIPTION

The ­lpt driver provides an interface to the parallel interface normally used for printers.  The specifiers 1, 2, and 3 correspond to the parallel interfaces at PC ports 0x3bc, 0x378, and 0x278 respectively. 

­Lpt?data is write only.  Writing to it sends data to the interface.  This file is sufficient for communicating with most printers. 

Lpt?dlr, lpt?pcr, and ­lpt?psr are used for fine control of the parallel port.  Reading or writing these files corresponds to reading and writing the data latch register, printer control register, and printer status register.  These are used by programs to drive special devices. 

SOURCE

­/sys/src/9/pc/devlpt.c

Plan 9  —  December 11, 1999