The TDL-12 turns out to be a Q-Bus SCSI controller, emulating up to
four RL01/2 drives -- exactly what I needed! Glen's web page even
includes a PDF of the original TD Systems manual for the board.
So, Glen, whoever and wherever you are, I thank you from the bottom of
my heart for creating and maintaining a web page about this orphan
controller. You have saved me a lot of time, effort, and probably
a bit of money as well.
Glad you found it helpful. I forget where I got the TDL-12 manual,
probably from someone who responded to questions about it on the
www.vcfed.org forum.
-Glen