Proteon ProNET CNX 500 Router Motherboard Vintage 1990 12-452580 AMD AM29000 CPU

Proteon ProNET CNX 500 Router Mainboard. Vintage early 1990s networking item, purchased as government surplus (USAF?). 

Includes AMD Am29000-25GC processor with heatsink. NEC MC-421000A32B-70 SIMM memory. Other ICs and components, please see photos. 

PCB weight is 2.1lbs.