shithub: 9ferno

ref: 6966e8d72ae8fb72ebf98909acbd464aff84a3cc

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.TH LPT 3 
.SH NAME
lpt \- parallel port interface
.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 0x378, 0x3bc, 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.
The data is written as a hexadecimal
(leading
.BR 0x ),
octal
(leading
.BR 0 )
or decimal number.
Reads return a hexadecimal number representing the value of the register.
.SH SOURCE
.B /os/*/devlpt.c