I’ve a not working Major Havoc board.
Let’s go to have a look to this rare board.
It has the “Quad Pokey” installed. In the same picture you can see the SN UR148
First of all as you can see it is quite different from all other (vector) atari boards. Vector D/A circuit is more complex than usual.
It has some “wires” and actually I dunno if these additional wires are factory modifications or not.
As you can see in the 3rd picture and in the next one this board was dedicated to the prototype TOLLIAN’S WEB so I don’t know if the modifications are due to adapt the board to the final software release.
RAMs and ROMs have been verified and seem to be ok.