Driver:	TWDAT, Version 4.20.00 June 02, 1993
	Copyright (c) 1990-1993, Emeritus Technologies.
	All rights reserved.

	TapeWare DAT SCSI-2 device driver

	Date		Mod	Description
	-----------	---	-----------------------------------------------
	25-Aug-1990	RAC	Started creating this driver.

	29-Jan-1990	RAC	Changed the reading and writing is carried out.
				It is now identical to the with the way
				TapeWare 2.16C works.

	29-Jan-1990	RAC	Added dispatch to dStopWrite to call dCheck-
				AndStartWrite to make sure the buffers are
				flushed prior to performing close.

	29-Jan-1990	RAC	Added polling to make sure the device keeps
				going...

	05-Apr-1990	RAC	Changed format to allow directory sizes >
				255Mb with the DIRSIZE parameter. This allows
				us to create "short" tapes.

	22-Apr-1991	MDB	Corrected error's in initialization which
				hung the driver if no tape was inserted and
				fixed bug in Mount Media which reported tape
				not formatted when no tape was inserted.

	22-Apr-1991	MDB	Per Rod, this driver no longer supports
				partitioned tapes.

	23-Apr-1991	MDB	Added options -BUFFUSE= and -MULTIMODE= to
				support multi-buffer read/writes during
				information transfer phases. the -BUFFUSE=
				parameter controls the maximum percentage 
				of the TapeWare main data buffer to be used
				during a single transfer command. The
				-MULTIMODE= parameter selects whether or not
				multiple buffers may be transferred during a
				single data phase.

	June 12, 1991	MDB	Added mutual exclusion to polling routines

	July 13, 1991	MDB	removed polling routine from list
				when dSeekBlock is called.

	24-July-1991	RAC	Removed extraneous cmd line parameters.
				Remove TYPE= option. The only way to specify
				the type is via the SCSI Inquiry cmd. Also,
				fixed up Get Media Table to recognize the
				WangDAT-2600 and return the appropriate
				tape type.

	30-Jul-1991	RAC	Added auto block size recognition within
				mount media.

	06-Sep-1991	MDB	Changed block size recognition algorithm. We
				now attempt a block read using variable length
				blocks (length specified by preferred block
				size parameter). If an error is detected, the
				residual length field of the request sense
				data will contain the byte value used to
				adjust to the proper block size.

	24-Sep-1991	RAC	Added support for 3.01 header files and
				Borland C++ compiler. Changed version number
				to 3.01.00.

	25-Nov-1991	MDB	Added device recognition for Hewlett Packard
				HP-35470 and HP-35480 devices.

	3-Dec-1991	MDB	Added support for WangDAT 3200 DC drive.

	27-Jan-1992	MDB	Changed version number to 4.00

	26-Feb-1992	MDB	Corrected potential error in MountMedia. If the
				first block on a tape is a file mark, we were
				singaling a block read to TapeWare. This was
				really bad form!

	5-Mar-1992	MDB	Corrected for compiler optimization of code to
				check for EOMpreset.

	27-Mar-1992	MDB	Set Action to ACTIVE prior to calling
				PerformIOPB(); This way, if we get an IRQ
				before PerformIOPB returns, Action will not
				be left active.

	15-Jul-1992	MDB	Fixed formatting problem on HP drives. These
				drives return an EOM indication when reading
				an unformatted tape.

	22-Jul-1992	MDB	Added support for WangDAT model 3100.

	05-Aug-1992	MDB	Added dispatch to time delay functions.

	13-Aug-1992	MDB	Changed format routine to detect a condition
				where we have tried to write to the tape in
				our preferred block size and upon reading
				the tape we find the block size is still
				incorrect.

	02-Sep-1992	MDB	Corrected bug in dCheckStatus that was not
				reporting controller level errors during
				streaming read/write operations.

	12-Jan-1993	RAC	Fixed problem with override. Now specific 
				a number (1-10) which you want the drive to
				be recognized as. Also, added the check for
				"ARCHIVE Python" instead of just "ARCHIVE".
				Also remove check for Wangtek. The Wangtek
				drive (6130x) is no longer supported at all!

	13-Jan-1993	RAC	Added the R-Byte DAT to the recognition table

	30-Jan-1993	RAC	Updated driver revision to 4.10.00

	03-Mar-1993	RAC	Added the Exabyte 4200 and 4200c

	12-Apr-1993	RAC/GMM	Added support for the Marker Write/Find cmds
				and Sony.  Verson change to 4.20 

	11-May-1993	GMM	Add multiblock R/W support.

	14-May-1993	GMM	Eliminate un-necessary loader message display
				delays.

	02-Jun-1993	GMM	Add fix for HP dat LOAD command response.

