Cromemco 8K Bytesaver-II  
The Cromemco Bytesaver could accommodate eight 2708 UV erasable EPORMS. It was a follow-on to their Bytesaver board with the addition of Cromemco style bank select capability.

Like the origional Bytesaver, it had an integral PROM programmer along with a DC to DC power supply to generate the required 12V programming voltage. They supplied the software as well though the typical Cromemco Z80 board monitor software had a burn PROM function with this board. The switch at the top left corner was there to prevent accidental programming. PROM burning was precicely controlled using an onboard pulse with control circuit.
 
The manual for the board can be obtained here.