A SCSI library can have only 1 type of drive; an ACSLS library can have 2
(maybe more, I don't know).

We run TSM for AIX, ACSLS 5.3, STK9710 robots.
At various times we have run 3490 & DLT drives in the same robot, then DLT
and 9840 drives in the same robot.  Certainly makes media conversion
easier!!

TSM doesn't really "support" it, but what you do is install ACSLS, which
gives you it's own robot driver on the robot address.  Then you just define
two TSM libraries on the same physical robot address.  Then you checkin one
type of tape to the first "library", and the other type of tape to the other
"library".  It should work unless there is something strange about the LTO
support that prevents it.

Check with STK, see if they can find other customers doing it...