John Clogg writes in comment to my suggestion about configuring the DLT
as a DDS:

>Worth a try!  By the way, there is *one* manufacturer of DLT drives in the
>world, so presumably they all share the same capabilities.

True, they may all be Quantum mechanisms, the but firmware each OEM
puts on them can be (and probably is) different. This was the case
for the DEC drives that ORBiT sells as compared to non DEC drives.