The old Unix machines are poor in connectivity with modern media as eg usb.
If the Unix machine is not yet in a Network with the Pc´s i should rather propose to go in this direction.
i found a other treat in this forum and if i remember right we dit it in the time of changing from Unix to windows as described in the answer of Walter Geppert.
http://www.cocreateusers.org/forum/showthread.php?t=2922
We had a first pc with a special lan-card that had a conector for the unix lan cable
https://en.wikipedia.org/wiki/BNC_connector
But i think the problem is not to find the hardware, rather to find someboddy who makes the configuration.
In our case this was also made by our local dealer.