.\"	$OpenBSD: mtio.4,v 1.16 2015/09/10 17:55:21 schwarze Exp $
.\"	$NetBSD: mtio.4,v 1.4 1996/03/03 17:13:54 thorpej Exp $
.\"
.\" Copyright (c) 1983, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     from: @(#)mtio.4	6.5 (Berkeley) 3/27/91
.\"
.Dd $Mdocdate: September 10 2015 $
.Dt MTIO 4
.Os
.Sh NAME
.Nm mtio
.Nd magtape interface
.Sh SYNOPSIS
.In sys/mtio.h
.Sh DESCRIPTION
This interface concerns devices which are typical tape block devices,
see
.Xr physio 9 .
.Pp
The conventional device letters/numbers
is applicable to any of the transport/controller pairs.
(But note that only 1600
.Tn BPI
is available with the
.Tn TS11 ,
and that 800
.Tn BPI
is not applicable to
.Tn TM78 . )
.Pp
When the device last number is between
.Em 0-7
the device will operate at 800
.Tn BPI
(or its lowest density), between
.Em 8-15
it will operate at 1600
.Tn BPI
(or its second density), and between
.Em 16-23
it will operate at 6250
.Tn BPI .
.Pp
The rewind devices automatically rewind
when the last requested read, write or seek has finished, or the end of the tape
has been reached.
The letter
.Ql n
is usually prepended to
the name of the no-rewind devices.
.Pp
Unix tapes are written in multiples of 1024 byte block
records.
Two end-of-file markers mark the end of a tape, and
one end-of-file marker marks the end of a tape file.
If the tape is not to be rewound it is positioned with the
head in between the two tape marks, where the next write
will overwrite the second end-of-file marker.
.Pp
All of the magtape devices may be manipulated with the
.Xr mt 1
command.
.Pp
The include file
.In sys/mtio.h
defines the various
.Xr ioctl 2
operations available on raw magnetic tape.
.Sh FILES
.Bl -tag -width /dev/rmt? -compact
.It Pa /dev/mt?
.It Pa /dev/rmt?
.El
.Sh SEE ALSO
.Xr mt 1 ,
.Xr tar 1 ,
.Xr intro 4 ,
.Xr st 4
.Sh HISTORY
The
.Nm
manual appeared in
.Bx 4.2 .
.Sh BUGS
The status should be returned in a device independent format.