There’s kind of a good write-up at:

http://www.chichak.ca/file/Tek_TWD120.html

Picked one of these units up new in the box about 12 or so years ago to play with. Didn’t have a laptop with an external SCSI port so it got relinquished to the equipment shelves where it still gathers dust. Would like to try to get it going in my spare time but there are obviously other pressing issues to deal with.

Besides, it is a lot easier to fire up a recent model digital scope to use.

Greg