.\" $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?"
.Pp
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
.Pa /dev/io
interface.
.Pp
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.
.Pp
The
.Fn ioctl
interface is slow, and there is no way (yet) to chain multiple
operations together.
.Pp
The headers required for user applications are not installed as
part of the standard system.