Ask around on LEMswap, somebody maybe a week or two ago was giving away a copy for classic mac (v4 maybe?).
I have retrospect for A/UX and V2.x for 68 mac (think it works with PPC as well).
The issues you will have is the software needs a driver for the model DAT you are going to use, I have no problem with SONY DDS2 models on 68k macs but I have not tried the DDS3 and DDS4 units with it.
Old, but in case someone looks up the thread in the future...
The full version of Retrospect has drivers built in for most of the tape drives that it supports. Of course, if one has a tape drive newer than the version of Retrospect, one may be out of luck unless there was a supplement or update.
The original poster appears to have a DDS2 drive so Retrospect 4 or 5 should serve his needs.
