I've been working on a Gottlieb "The Amazing Spider-Man" and I finally got the MPU board (System 80) working well enough to boot up (bad 6502 and one bad 6532). The machine turns on and flashes the lights. A press of the self-test switch gets it into attract mode, but the credit display is blank.

When I press the self-test switch again, it goes into the self-test, everything checks out except the memory test (20). This test reports "bad" memory on component 7641-1, which would be PROM-1. Then, after 10 seconds, it shows me a 20 99 for 5 seconds, which is supposed to mean that the memory tests all passed. It cycles back and forth between 7641-1 and 99.

This board came to me with no chips populated in PROM-1 and PROM-2 (Z38 & Z37), and the parts list in the manual doesn't list any parts for those sockets. In addition, the ROM images I find online are only for U2 & U3 ROMs. All of this leads me to believe that there was no PROM-1 for this game.

Does anyone know for sure? Am I missing a chip at Z38?
#spider-man-amazing

Memory Error 7641-1 (resized).jpg

I should mention that this board is ASSY PB03-D100-011 DETAIL PB03-D107-003, which makes it a 3rd Generation System 80 board, I suppose.
The U2 and U3 ROMs are original on this board, and soldered directly in, but I was able to read & verify them by using the TC1 socket with the 6502 removed. Check sums are good on U2 and U3 and the self-test doesn't complain about them. All the addressing lines are working, the question is did the board ship with PROM1 and/or PROM2, or are those sockets just for expansion.

I've read pinwiki a bunch of times, trying to understand and it appears that there should be a masked PROM at Z38 for the game code? I'm just unsure why I can't seem to find any binaries for PROM-1 or why it's not listed in the manual's parts list.

I suppose I've answered my own question at this point, because going through the disassembled code on U2, I see that there are instructions that reference memory at $1000. Example:
222A BD 00 10 LDA $1000,X

Looking at the address lines, it appears that PROM-1 would address between 0x1000 - 0x11FF, so I guess I have to track down that binary and burn a chip.

Still, it would make me more confident if someone with more experience could definitively tell me what's going on with this board. All the binaries I've found so far only mention U2 & U3, addressed at 0x2000 and 0x3000 for a total of 4k. I don't see any reference to more than that...

Thanks in advance to anyone who can educate me!

Found the answer - forget I asked. From Action Pinball:

This is the first System 80 CPU board. This board is only used on the first 5 System 80 games (Spiderman (#653), Panthera (#652), Circus (#654), Counterforce (#656), Star Race (#657)). It uses 2 game ROM chips (PROM1 and PROM2). This board must be modified for using replacement PROM1 and/or PROM2 chips, or replacment U2 and U3 chips. See modification information at the bottom of this section.

I also found images for the PROMs - 653-1 and 653-2 files that are 512 bytes each.

Thanks so much for the help!
I have the PB03-D107-003, which is like the second generation in terms of the addressing of PROM1. So, as mentioned, I can combine PROM1 + PROM2 into a single 2716 and install it at PROM1. I don't have any 2716s right now, so it will take me a week to get one and find out if this is the last problem on this board.

I like to verify, but it took me an hour to track down the schematic for the board that I have. The machine came with a Spider-Man manual, but that's for the first generation revision of the 80 board, and that's not what is installed. Anyway, as I'm sure you know (but I'm recording here in case anyone else ever stumbles on this thread), the -002 and -003 boards both have E4 by default (as mentioned) to supply +5V to PROM1. /CE is /BAB12, /OE=NAND(/BAB11 and /BAB13), so PROM1 is addressed from 0x1000 to 0x17FF, and PROM2 is unused with the default jumpers.

Thanks again for the help. It all makes sense now but it took a lot of times through the documentation before any of this made sense to me. Gottlieb...

IMG_1545 (resized).jpg