The 7864 is an 8088 processor card with RAM and ROM intended for a multiprocessor environment. The ROM may contain a monitor, but i have no information on it. It is even possible that it uses the 7303 Keyboard & Display Card.
I do have a manual for this board, but with so much undisclosed programmable logic it would be difficult to find faults. I would probably start with an off the shelf monitor and customise it for this board and a suitable serial card.
This card was originally set up as a slave, but i have converted it to a master. The resistor pack is a bit rough.
I tried this card with the only likely serial card match, but i did not get a prompt.