shithub: riscv

ref: 9adaf2e7f8a81eb207eb7894e80864019950e0e7
dir: /sys/man/3/lpt/

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.TH LPT 3 
.SH NAME
lpt \- parallel port interface for PC's
.SH SYNOPSIS
.nf
.B bind -a #L[123] /dev

.B /dev/lpt[123]data
.B /dev/lpt[123]dlr
.B /dev/lpt[123]pcr
.B /dev/lpt[123]psr
.fi
.SH DESCRIPTION
The
.I lpt
driver provides an interface to the parallel
interface normally used for printers.
The specifiers
.BR 1 ,
.BR 2 ,
and
.BR 3
correspond to
the parallel interfaces at PC ports 0x3bc, 0x378, and 0x278
respectively.
.PP
.B Lpt?data
is write only.
Writing to it sends data to the interface.
This file is sufficient for communicating with most printers.
.PP
.BR Lpt?dlr ,
.BR lpt?pcr ,
and
.B 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.
.SH SOURCE
.B /sys/src/9/pc/devlpt.c