MT(4) | Device Drivers Manual (vax) | MT(4)

# NAME

`mt` —
TM-78/TU-78 MASSBUS mag tape interface

# SYNOPSIS

`mt0 at mba? drive ? tape mu0 at mt0 slave 0`

# DESCRIPTION

The TM-78/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 without 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), mtio(4), vax/tm(4), vax/ts(4), vax/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.

February 17, 2017 | NetBSD 10.0