freebsd-dev/share/man/man4/man4.i386/lpt.4

.\"
.\" Copyright (c) 1993 Christopher G. Demetriou
.\" Copyright (c) 1994 Geoffrey M. Rehmet
.\" All rights reserved.
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.\"      This product includes software developed by Christopher G. Demetriou.
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.\"	from: lpt.4,v 1.1 1993/08/06 10:34:12 cgd Exp
.\"	$Id: lpt.4,v 1.7 1998/10/15 20:27:26 wosch Exp $
.\"
.Dd August 28, 1993
.Dt LPT 4 i386
.Os FreeBSD
.Sh NAME
.Nm lpt
.Nd
Parallel port driver
.Sh SYNOPSIS
For interrupt-driven ports:
.Cd "device lpt0 at isa? port" \&"IO_LPT1\&" tty irq 7
.Cd "device lpt1 at isa? port" \&"IO_LPT2\&" tty irq 7
.Cd "device lpt2 at isa? port" \&"IO_LPT3\&" tty irq 7
.Pp
For BIOS-probed ports:
.Cd "device lpt0 at isa? port? tty irq 7"
.Pp
For polled ports:
.Cd "device lpt0 at isa? port? tty"
.Cd "device lpt1 at isa? port" \&"IO_LPT2\&" tty
.Sh DESCRIPTION
This driver provides access to parallel ports. 
.Pp
The driver can be configured either to be either interrupt-driven, or 
to poll the printer.  Ports that are configured to be 
interrupt-driven can be switched to polled mode by using the
.Xr lptcontrol 8
command.
.Pp
This driver replaces the functionality of the 
.Xr lpa 4
driver, which is now defunct.
.Sh FILES
.Bl -tag -width Pa -compact
.It Pa /dev/lpt0
first parallel port driver
.El
.Sh SEE ALSO
.Xr lp 4 ,
.Xr lptcontrol 8
.Sh BUGS
There are lots of them, especially in cheap parallel port implementations.
.Pp
It is only possible to open a lpt port when a printer is connected and
on-line, making it impossible to run 
.Xr lptcontrol 8 
when there is no printer connected.
.Pp
This driver could still stand a rewrite.