BNC or AUI
A Sun 3/50 or 3/60 is equipped with both an AUI and a BNC ethernet
port. But how can i switch between 'em?
If you take out the mainboard you can find a dip switch block near
the ethernet ports. Flip all eight switches into the direction of
the desired port and you're done.
On the mainboard near the battery is a set of eight jumpers.
Six of 'em configure the memory size (4M,8M,...,24M), one
changes the video resolution (HIGRES) and one controls the
ethernet ports (EXTUR). If you pull this jumper, the BNC
port is activated.