I have a tabby here, it is indeed a very small GFX Tablet, but it works very good.
To be honest it was lying in a corner until this topic came along, so I took it
out of its box and connected it. It connects to the serial port on the back of
my Falcon. I thought it would replace the mouse but no.
But you can use them both at the same time.
Anyway, the was a disk included with special drivers for it.
Made a .ZIP of it, maybe you can use them...http://www.xs4all.nl/~bonus/TABBY.zip