I was also looking for this capability. A company called "NovaStor" sells
something called "Tape Processing Utilities" for about $400. It doesn't make
the tape look like a hard disk, but it will allow you better access to the tape
drive than using tape backup programs. I talked with Pete Means at
(818)707-9900. As stated by someone on this forum when I was looking into
this, it's probably cheaper (and easier) just to buy a magneto-optical drive
instead.
LAM