1.\" Copyright (c) 1996 2.\" Mike Pritchard <mpp@FreeBSD.org>. All rights reserved. 3.\" 4.\" Copyright (c) 1983, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)mtio.4 8.1 (Berkeley) 6/5/93 36.\" 37.Dd February 11, 1996 38.Dt MTIO 4 i386 39.Os FreeBSD 2.2 40.Sh NAME 41.Nm mtio 42.Nd 43.Tn FreeBSD 44magtape interface 45.Sh DESCRIPTION 46The special files 47named 48.Pa /dev/[nr]st* 49refer to SCSI tape drives, 50which may be attached to the system. 51.Pa /dev/[nr]st*.ctl 52are control devices that can be used to issue ioctls to the SCSI 53tape driver to set parameters that are required to last beyond the 54unmounting of a tape. 55.Pp 56.Pp 57The rewind devices automatically rewind 58when the last requested read, write or seek has finished, or the end of the tape 59has been reached. The letter 60.Ql n 61is usually prepended to 62the name of the no-rewind devices. 63.Pp 64Tapes can be written with either fixed length records or variable length 65records. See 66.Xr st 4 67for more information. Two end-of-file markers mark the end of a tape, and 68one end-of-file marker marks the end of a tape file. 69If the tape is not to be rewound it is positioned with the 70head in between the two tape marks, where the next write 71will over write the second end-of-file marker. 72.Pp 73All of the magtape devices may be manipulated with the 74.Xr mt 1 75command. 76.Pp 77A number of 78.Xr ioctl 2 79operations are available 80on raw magnetic tape. 81The following definitions are from 82.Aq Pa sys/mtio.h : 83.Bd -literal 84/* 85 * Structures and definitions for mag tape io control commands 86 */ 87 88/* structure for MTIOCTOP - mag tape op command */ 89struct mtop { 90 short mt_op; /* operations defined below */ 91 daddr_t mt_count; /* how many of them */ 92}; 93 94/* operations */ 95#define MTWEOF 0 /* write an end-of-file record */ 96#define MTFSF 1 /* forward space file */ 97#define MTBSF 2 /* backward space file */ 98#define MTFSR 3 /* forward space record */ 99#define MTBSR 4 /* backward space record */ 100#define MTREW 5 /* rewind */ 101#define MTOFFL 6 /* rewind and put the drive offline */ 102#define MTNOP 7 /* no operation, sets status only */ 103#define MTCACHE 8 /* enable controller cache */ 104#define MTNOCACHE 9 /* disable controller cache */ 105 106#if defined(__FreeBSD__) 107/* Set block size for device. If device is a variable size dev */ 108/* a non zero parameter will change the device to a fixed block size */ 109/* device with block size set to that of the parameter passed in. */ 110/* Resetting the block size to 0 will restore the device to a variable */ 111/* block size device. */ 112 113#define MTSETBSIZ 10 114 115/* Set density values for device. They are defined in the SCSI II spec */ 116/* and range from 0 to 0x17. Sets the value for the opened mode only */ 117 118#define MTSETDNSTY 11 119 120#define MTERASE 12 /* erase to EOM */ 121#define MTEOD 13 /* Space to EOM */ 122#define MTCOMP 14 /* select compression mode 0=off, 1=def */ 123#define MTRETENS 15 /* re-tension tape */ 124 125#endif 126 127/* structure for MTIOCGET - mag tape get status command */ 128 129struct mtget { 130 short mt_type; /* type of magtape device */ 131/* the following two registers are grossly device dependent */ 132 short mt_dsreg; /* ``drive status'' register */ 133 short mt_erreg; /* ``error'' register */ 134/* end device-dependent registers */ 135 short mt_resid; /* residual count */ 136#if defined (__FreeBSD__) 137 daddr_t mt_blksiz; /* presently operating blocksize */ 138 daddr_t mt_density; /* presently operating density */ 139 daddr_t mt_comp; /* presently operating compression */ 140 daddr_t mt_blksiz0; /* blocksize for mode 0 */ 141 daddr_t mt_blksiz1; /* blocksize for mode 1 */ 142 daddr_t mt_blksiz2; /* blocksize for mode 2 */ 143 daddr_t mt_blksiz3; /* blocksize for mode 3 */ 144 daddr_t mt_density0; /* density for mode 0 */ 145 daddr_t mt_density1; /* density for mode 1 */ 146 daddr_t mt_density2; /* density for mode 2 */ 147 daddr_t mt_density3; /* density for mode 3 */ 148/* the following are not yet implemented */ 149 u_char mt_comp0; /* compression type for mode 0 */ 150 u_char mt_comp1; /* compression type for mode 1 */ 151 u_char mt_comp2; /* compression type for mode 2 */ 152 u_char mt_comp3; /* compression type for mode 3 */ 153#endif 154 daddr_t mt_fileno; /* file number of current position */ 155 daddr_t mt_blkno; /* block number of current position */ 156/* end not yet implemented */ 157}; 158 159/* 160 * Constants for mt_type byte. These are the same 161 * for controllers compatible with the types listed. 162 */ 163#define MT_ISTS 0x01 /* TS-11 */ 164#define MT_ISHT 0x02 /* TM03 Massbus: TE16, TU45, TU77 */ 165#define MT_ISTM 0x03 /* TM11/TE10 Unibus */ 166#define MT_ISMT 0x04 /* TM78/TU78 Massbus */ 167#define MT_ISUT 0x05 /* SI TU-45 emulation on Unibus */ 168#define MT_ISCPC 0x06 /* SUN */ 169#define MT_ISAR 0x07 /* SUN */ 170#define MT_ISTMSCP 0x08 /* DEC TMSCP protocol (TU81, TK50) */ 171#define MT_ISCY 0x09 /* CCI Cipher */ 172#define MT_ISCT 0x0a /* HP 1/4 tape */ 173#define MT_ISFHP 0x0b /* HP 7980 1/2 tape */ 174#define MT_ISEXABYTE 0x0c /* Exabyte */ 175#define MT_ISEXA8200 0x0c /* Exabyte EXB-8200 */ 176#define MT_ISEXA8500 0x0d /* Exabyte EXB-8500 */ 177#define MT_ISVIPER1 0x0e /* Archive Viper-150 */ 178#define MT_ISPYTHON 0x0f /* Archive Python (DAT) */ 179#define MT_ISHPDAT 0x10 /* HP 35450A DAT drive */ 180#define MT_ISMFOUR 0x11 /* M4 Data 1/2 9track drive */ 181#define MT_ISTK50 0x12 /* DEC SCSI TK50 */ 182#define MT_ISMT02 0x13 /* Emulex MT02 SCSI tape controller */ 183 184/* mag tape io control commands */ 185#define MTIOCTOP _IOW('m', 1, struct mtop) /* do a mag tape op */ 186#define MTIOCGET _IOR('m', 2, struct mtget) /* get tape status */ 187#define MTIOCIEOT _IO('m', 3) /* ignore EOT error */ 188#define MTIOCEEOT _IO('m', 4) /* enable EOT error */ 189 190#ifndef KERNEL 191#define DEFTAPE "/dev/nrst0" 192#endif 193 194#ifdef KERNEL 195/* 196 * minor device number 197 */ 198 199#define T_UNIT 003 /* unit selection */ 200#define T_NOREWIND 004 /* no rewind on close */ 201#define T_DENSEL 030 /* density select */ 202#define T_800BPI 000 /* select 800 bpi */ 203#define T_1600BPI 010 /* select 1600 bpi */ 204#define T_6250BPI 020 /* select 6250 bpi */ 205#define T_BADBPI 030 /* undefined selection */ 206#endif 207#endif /* _SYS_MTIO_H_ */ 208.Ed 209.Pp 210.Sh FILES 211.Bl -tag -width /dev/[nr]st* -compact 212.It Pa /dev/[nr]st* 213.El 214.Sh SEE ALSO 215.Xr mt 1 , 216.Xr tar 1 , 217.Xr st 4 218.Sh HISTORY 219The 220.Nm mtio 221manual appeared in 222.Bx 4.2 . 223An i386 version first appeared in 224.Fx 2.2 . 225.Sh BUGS 226The status should be returned in a device independent format. 227.Pp 228The special file naming should be redone in a more consistent and 229understandable manner. 230