Xylogic 772 tape controller - need help

[jim at EASBY.DURHAM.AC.UK]

Have a problem with a Xylogics 772 tape controller.  We aquired the
controller just over a year ago, and apart from the lack of support for
the mt commands (I hacked those in, inelegant but effective) it has
generally been OK running with a CDC Keystone 6250 bpi drive.  Now, our
file systems have grown to the point where a level 0 dump exceeds the
capacity of a single tape, and the 772 driver ignores the EOT.  So, to
save me from spending N hours figuring out how to fix the problem, has
anyone out there already done it?

BTW this is running on a 3/280 under 3.4

--Jim