(from the Windows Administrator's Guide, page 109)

Drivers for non-IBM Devices

If you manage a mixture of devices, you can control some with the Tivoli
Storage Manager device driver and others with the Windows device driver.
The way you set up competing device drivers determines which one
acquires devices when the server is started. The Tivoli Storage Manager
device drivers are available at
www.ibm.com/software/sysmgmt/products/support/IBMTivoliStorageManager.ht
ml. For devices not currently supported by the Tivoli Storage Manager
device driver, the Windows driver may be suitable. See "Requirements for
Using Windows Device Drivers with IBM Tivoli Storage Manager" on page
111 for more information.

--For the following tape devices, you can choose whether to install the
Tivoli Storage Manager device driver or the Windows device driver: 4MM
8MM DLT DTF QIC StorageTek SD3, 9490, 9840, and 9940 

--For optical, WORM, and Non-IBM LTO devices, you must install the
Tivoli Storage Manager device driver.

--Removable media devices (attached as local file systems) require the
Windows device driver.

--All SCSI-attached libraries that contain optical and tape drives from
the list above must use the Tivoli Storage Manager changer driver.

--Third party vendor device drivers are supported if they are supplied
by the hardware vendor and are associated with the GENERICTAPE device
class. Using a device class other than GENERICTAPE with a third party
vendor device driver is not recommended. Generic device drivers are not
supported in WORM device classes. For more information, see the DEFINE
DEVCLASS - GENERICTAPE command in the Administrator's Reference.

--
Mark Stapleton (stapleton AT berbee DOT com)
Office 262.521.5627