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 $NetBSD: ppi.4,v 1.4 2004/01/23 19:36:23 wiz Exp $

 Copyright (c) 1997
 Michael Smith

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 $FreeBSD: src/share/man/man4/ppi.4,v 1.4.2.7 2001/12/17 11:30:12 ru Exp $

.Dd December 29, 2003
.Dt PPI 4
.Os
.Sh NAME
.Nm ppi
.Nd "user-space interface to ppbus parallel port"
.Sh SYNOPSIS
.Cd "ppi* at ppbus?"

p
Minor numbering: Unit numbers correspond directly to
.Xr ppbus 4
numbers.
.Sh DESCRIPTION
The
.Nm
driver provides a convenient means for user applications to manipulate
the state of the parallel port, enabling easy low-speed I/O operations
without the security problems inherent with the use of the

a /dev/io
interface.

p
The programming interface is described in
.Xr ppi 9 .
.Sh SEE ALSO
.Xr atppc 4 ,
.Xr io 4 ,
.Xr ppbus 4 ,
.Xr ppi 9
.Sh HISTORY
.Nm
originally appeared in
.Fx .
.Sh AUTHORS
This manual page is based on the
.Fx
.Nm ppi
manual page and was updated for the
.Nx
port by
.An Gary Thorpe .
.Sh BUGS
The inverse sense of signals is confusing.

p
The
.Fn ioctl
interface is slow, and there is no way (yet) to chain multiple
operations together.

p
The headers required for user applications are not installed as
part of the standard system.