From: Sergey Ryzhkov, Serge Vakulenko

From: Sergey Ryzhkov, Serge Vakulenko
E-mail: <sir@kiae.su>, <vak@zebub.msk.su>
added new /dev/wt entries for wt.c version 1.3

8) Some controllers support only 1024 block length.
   Setting WT_BSIZE bit in device minor number turns on this mode.

Minor number structure:
	0bfffuuu
Fields:
	uuu   - Unit number. It's possible to install
		up to three tape controllers on the same machine,
		using DRQs 1..3.  Hence, unit number can lie
		in range 0..2.
	fff   - Tape format number:
		0 - /dev/rwt0  - default density (auto select)
		1 - /dev/rwt0a - QIC 11 (obsolete)
		2 - /dev/rwt0b - QIC 24 (60 megabytes)
		3 - /dev/rwt0c - QIC 120 (120 megabytes)
		4 - /dev/rwt0d - QIC 150 (150 megabytes)
		5 - /dev/rwt0e - QIC 300 (300 megabytes?)
		6 - /dev/rwt0f - QIC 600 (600 megabytes?)
	b     - Long block size flag.  With this bit set,
		the driver will perform all i/o operations
		with the controller using 1024-byte
		blocks, instead of 512 ones.
		Some controllers need it (CMS for example).
		If you Wangtek controller does not stream well,
		you can try to use /dev/rWt0 device instead
		of /dev/rwt0 (uncomment needed lines in /dev/MAKEDEV
		to create it).

Block interface (writing blocks less than 2048 bytes) is not functioning
pwoperly.  Use raw interface instead.

Thanks to all who helped to test it on the following hardware:

Controller           Drive            Volume    Interface     Thanks to
---------------------------------------------------------------------------
Archive SC-499       Archive 2150L    150 Meg   QIC-02        KIAE
CMS?                 ?                150 Meg   QIC-02        KIAE
Everex EV 831/833    ?                ?         QIC-36        Joergen Haegg
Wangtek ASSY         Wangtek          60 Meg    QIC-02        Ken Whedbee
Tecmar QT150i?       Wangtek 5150EQ   ?         QIC-02?       Marko Teiste
?                    Wangtek 5099EK   60 Meg    QIC-36        Robert Shien
Archive SC400S       ?                60 Meg    ?             Warren Toomey