If you’re using a Rottendog MPU in your Data East or SEGA pinball machine you’ll need to pay attention to jumpers J4 and J5.

Only one needs to be installed and it depends on which ROMs your game uses. A single 27C512 in C5 will require J5 installed and J4 removed.

If your game uses 2 ROMs, a 27C128 in B5 and a 27C256 in C5, then J5 needs to be removed and J4 installed.

The board comes with both installed so you can just cut out the one you don’t need.

If you’re installing one of these boards and it’s not working check these jumpers first.