Very Computer

I am using Bjorn Ekwall's excellent DE620 driver with a
Thinkpad 340 and kernel 1.3.9.  It works perfectly.  However,
I want to use the DE621 multiplexer, which allows one to use
both the ethernet adaptor and the printer on the same parallel
port. Unfortunately, the DE620 driver doesn't support the use
of the DE621.  Is there another driver?  Doesn anyone know
what has to be sent to the DE621 to have it switch between the
printer and the ethernet adaptor?
Best wishes,
Bob