Do we have a manual showing the error codes used by MDM in their MPU4 version of "Tuppeny Nudger" ?
I am working on a board using that ROM as I had a three reel set handy and its throwing up lots of random errors - 6.1, 6.2 etc - I think its something to do with switches but not sure, lots of bad traces on this board its taking me a wee while to even get it booting!