MT(4)                  OpenBSD Programmer's Manual (VAX)                 MT(4)

NAME
     mt - TM78/ TU-78 MASSBUS magtape interface

SYNOPSIS
     mt* at mscpbus? drive?

DESCRIPTION
     The TM78/ TU-78 combination provides a standard tape drive interface as
     described in mtio(4). Only 1600 and 6250 BPI are supported; the TU-78
     runs at 125 IPS and autoloads tapes.

DIAGNOSTICS
     mu%d: no write ring.  An attempt was made to write on the tape drive when
     no write ring was present; this message is written on the terminal of the
     user who tried to access the tape.

     mu%d: not online.  An attempt was made to access the tape while it was
     offline; this message is written on the terminal of the user who tried to
     access the tape.

     mu%d: can't change density in mid-tape.  An attempt was made to write on
     a tape at a different density than is already recorded on the tape.  This
     message is written on the terminal of the user who tried to switch the
     density.

     mu%d: hard error bn%d mbsr=%b er=%x ds=%b.  A tape error occurred at
     block bn; the mt error register and drive status register are printed in
     octal with the bits symbolically decoded.  Any error is fatal on non-raw
     tape; when possible the driver will have retried the operation which
     failed several times before reporting the error.

     mu%d: blank tape.  An attempt was made to read a blank tape (a tape with-
     out even end-of-file marks).

     mu%d: offline.  During an i/o operation the device was set offline.  If a
     non-raw tape was used in the access it is closed.

SEE ALSO
     mt(1), tar(1), tp(1), mtio(4), tm(4), ts(4), ut(4)

HISTORY
     The mt driver appeared in 4.1BSD.

BUGS
     If a physical error (non-data) occurs, mt may hang ungracefully.

     Because 800 BPI tapes are not supported, the numbering of minor devices
     is inconsistent with triple-density tape units.  Unit 0 is drive 0, 1600
     BPI.

OpenBSD 2.9                     March 27, 1991                               1
