UT(4)                                                                    UT(4)



NAME
       ut - UNIBUS TU45 tri-density tape drive interface

SYNOPSIS
       controller ut0 at uba0 csr 0172440 vector utintr
       tape tj0 at ut0 drive 0

DESCRIPTION
       The  _u_t interface provides access to a standard tape drive interface as
       describe in _m_t_i_o(4).  Hardware implementing this on the VAX is typified
       by  the System Industries SI 9700 tape subsystem.  Tapes may be read or
       written at 800, 1600, and 6250 bpi.

SEE ALSO
       mt(1), mtio(4)

DIAGNOSTICS
       tj%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.

       tj%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.

       tj%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.

       ut%d:  soft  error bn%d cs1=%b er=%b cs2=%b ds=%b.  The formatter indi‐
       cated a corrected error at a  density  other  than  800bpi.   The  data
       transferred is assumed to be correct.

       ut%d: hard error bn%d cs1=%b er=%b cs2=%b ds=%b.  A tape error occurred
       at block _b_n.  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.

       tj%d: lost interrupt.  A tape operation did not complete within a  rea‐
       sonable  time,  most  likely because the tape was taken off-line during
       rewind or lost vacuum.  The controller should, but does  not,  give  an
       interrupt  in  these  cases.   The  device will be made available again
       after this message, but any current open reference to the  device  will
       return an error as the operation in progress aborts.

BUGS
       If  any non-data error is encountered on non-raw tape, it refuses to do
       anything more until closed.



4.2 Berkeley Distribution        May 15, 1985                            UT(4)