HT(4)		    UNIX Programmer's Manual		    HT(4)



NAME
     ht - TM-03/TE-16,TU-45,TU-77 MASSBUS magtape interface

SYNOPSIS
     /sys/conf/SYSTEM:
	  NHT  _h_t__d_r_i_v_e_s # TE16, TU45, TU77

     /etc/dtab:
	  #Name Unit# Addr   Vector Br Handler(s)      # Comments
	  ht	?     172440 224    5  htintr	       # tu 16 massbus tape

     major device number(s):
	  raw: 6
	  block: 0
     minor device encoding:
	  bits 0003 specify HT drive
	  bit  0004 specifies no-rewind operation
	  bit  0010 specifies 1600BPI recording density instead of 800BPI

DESCRIPTION
     The tm-03/transport combination provides a standard tape
     drive interface as described in _m_t_i_o(4).  All drives provide
     both 800 and 1600 bpi; the TE-16 runs at 45 ips, the TU-45
     at 75 ips, while the TU-77 runs at 125 ips and autoloads
     tapes.

FILES
     /dev/MAKEDEV	 script to create special files
     /dev/MAKEDEV.local  script to localize special files

SEE ALSO
     mt(1), tar(1), tp(1), mtio(4), tm(4), ts(4), dtab(5), auto-
     config(8)

DIAGNOSTICS
     tu%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.

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

     tu%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 termi-
     nal of the user who tried to switch the density.

     tu%d: hard error bn%d er=%b ds=%b.   A tape error occurred
     at block _b_n; the ht error register and drive status register
     are printed in octal with the bits symbolically decoded.



Printed 11/26/99	January 28, 1988			1






HT(4)		    UNIX Programmer's Manual		    HT(4)



     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.

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

     The system should remember which controlling terminal has
     the tape drive open and write error messages to that termi-
     nal rather than on the console.












































Printed 11/26/99	January 28, 1988			2