The BioNet 100 is an ethernet adapter for the Atari ACSI bus. It is partly
supported in Linux/m68k; originally it used to work in a BioNet 100
environment, consisting of a server (a PC running the server software
or an Atari TT), and the clients (running the BioNet clients for TOS).
There was also a VME Bus card for the TT, but I think this one isn't
supported at all (by Linux/m68k, that is).
I think there also was a driver for MiNT... But if you're just running
plain TOS without MiNT/MiNTNet, you're probably out of luck to use this adaptor in a standard ethernet environment using TCP-IP - at least as far as I know...
They were sold by Biodata in Germany (the company still exists, but
does not have any documentation about the old stuff anymore).