I do not believe there is any direct support in TSM for having 2 types of
drives within the same library.

You do not tell us your server platform, so I am not sure if this will help
you, as my experience is on AIX:

We did it with an STK9710 by defining 2 different TSM LIBRARY definitions.
A "LIBRARY" to TSM is actually a logical construct, not a physical one.  So
we just defined 2 library names, both pointing to the same AIX  /dev
address.

Then we defined our DLT drives to the first library name, and our 9840
drives to the second library name.  Then you run TWO checkin commands,
CHECKIN LIBV LIBRARY1 xxxxxxxxxxxxxxxx, followed by CHECKIN LIBV LIBRARY2
xxxxxxxxxxxx.

Our library was defined as TYPE=ACS, so I don't know if you can do the same
with a TYPE=SCSI library, or if you can do it with a Windows TSM server.

But this maybe will help you get started.

************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
************************************************************************