If you are employing StorageTek's ACSLS or LibStation, you can add
EDT-DistribuTAPE to the mix to support both tape drive types in one library.
The interface with TSM is via the external library manager (ELM) component.
In essence, you would create two library definitions in TSM, one for DLT and
one for 9840.  These definitions would be reflected in the configuration of
the EDT-DistribuTAPE product.  When a mount was requested, the proper media
based on the library definition being used by TSM would be mounted in the
appropriate drive and operations would proceed as normal.  This is an
excellent way to get the most out of your tape resources.  Furthermore, as
Zlatko stated below, this methodology will also allow you to migrate data
from one device type to another should you desire to do so.

Christopher S. Young
Senior System Engineer
Gresham Enterprise Storage
www.greshamstorage.com
Office: 303.413.1799 x 205
Mobile: 303.717.2745