Bally E-series Tech Questions

[ramegoom]

This is directed to the technical guys out there. I'm kind of new at this game and have a few questions regarding the EPROMs used on E2000 machines. It appears every CPU board is about the same, differences being with the game ROM's. Some have four of them, some have five.

I have a number of the spare boards and several clean machines, several different EPROMs between them, and trying to make heads or tails out of the numbering (or what's left of the numbering) on the chips. Most have been obliterated with that red seal tape, so for the most part, I have no idea what the payoff odds are - specifically on the P1 chips. Hopefully, the checksums will tell match with some sort of list, which possibly some of you techs might have. Sooooo, here goes:

1. If a machine has a P2 chip installed, can I simply remove it and will the machine play normally? Most of the machines I have don't have that socket populated, but some do. I believe it was for "tournament" use and is not functional for home use games - which is what I'm all about.

2. Can you swap P1 chips from game to game, or are they specific for that particular M1-2-3 group of PROMs?

3. Can the M3 chip be changed around with other ones that have different part numbers, or must it be matched to the M1 and M2 chips? If my research is correct, the M3 determines payout odds.

Seems like the checksums all have 00 on the second bit, regardless of the part numbers (M1, M2, M3, P2) and the P1 chips all have 56 on the second bit. This leads me to believe there is a routine that must have all of the checksums matching before the CPU can proceed. One bad checksum and the CPU kicks it into tilt. Am I correct in this?

4. Are there any calibration doc's available for these programs. Had to ask, although usually that stuff is held pretty closely to the manufacturers. But...Since the E2000's have been de-commissioned, I'd think someone out there would have some input here. My favorite past-time is hacking these things.

Inquiring minds want to know (at least one).
Thanks in advance for bearing with my questions.
John