mtio - magtape interface
This interface concerns devices which are typical tape block
The conventional device letters/numbers is applicable to any
transport/controller pairs. (But note that only 1600 BPI is
with the TS11, and that 800 BPI is not applicable to TM78.)
When the device last number is between 0-7 the device will
operate at 800
BPI (or its lowest density), between 8-15 it will operate at
1600 BPI (or
its second density), and between 16-23 it will operate at
The rewind devices automatically rewind when the last requested read,
write or seek has finished, or the end of the tape has been
letter `n' is usually prepended to the name of the no-rewind
Unix tapes are written in multiples of 1024 byte block
records. Two endof-file
markers mark the end of a tape, and one end-of-file
the end of a tape file. If the tape is not to be rewound it
with the head in between the two tape marks, where
the next write
will overwrite the second end-of-file marker.
All of the magtape devices may be manipulated with the mt(1)
The include file <sys/mtio.h> defines the various ioctl(2)
available on raw magnetic tape.
mt(1), tar(1), intro(4), st(4), wt(4)
The mtio manual appeared in 4.2BSD.
The status should be returned in a device independent format.
OpenBSD 3.6 January 7, 1996
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