HT(4)							     Kernel Interfaces Manual							     HT(4)

NAME

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

SYNOPSIS

       /sys/conf/SYSTEM:
	    NHT  ht_drives # 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 mtio(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), autoconfig(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  termi-
       nal 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 terminal 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 terminal 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 bn; the ht 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.

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 terminal rather than on the
       console.

3rd Berkeley Distribution					 January 28, 1988							     HT(4)