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 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 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.