Module Name:	syssrc
Committed By:	simonb
Date:		Tue Sep  7 13:53:36 UTC 1999

Modified Files:
	syssrc/sys/arch/pmax/dev: tz.c

Log Message:
Overhaul the tz SCSI tape driver:
 + Add a quirk table.
 + Assume all else is a modern drive that can do variable block
   lengths (this is the main reason for this work - the old driver
   only ever seemed to write 512 byte blocks!).
 + Keep track of values for mtget's mt_fileno, mt_blkno.
 + Handle a few extra MTIOCTOP commands.

Ideas gleaned from our MI scsi tape driver and the FreeBSD CAM tape
driver.  Tested on a TKZ09 (DEC badged Exabyte 8500), a TLZ06 (DEC
DAT) and TK50.

Many thanks to Pierre Bergdolt for helping with testing.


To generate a diff of this commit:
cvs rdiff -r1.20 -r1.21 syssrc/sys/arch/pmax/dev/tz.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.