Museum of the Game® & International Arcade Museum® Forums
Anyone have any real info on this guy? I just pulled this out of a GoldZone that's failing to shut off its "paying tickets/check ticket" sound. (This is unbelievably annoying!)
What I've figured out so far:
U1 - CPU, 80C32 clone, does pretty much everything, they even rely on the integrated RAM (there's no RAM chips here!)
U4 - Game program ROM, obviously.
U5 - EEPROM-SRAM hybrid NVRAM. It appears to use an external capacitor (U5C1) to power itself for a couple extra clicks so it can write SRAM out to EEPROM. Clever.
U301 - Sound ROM bank 1, again obvious.
U302 - Package of 4 mono DACs. More on this later.
U303 - Intended for a second Sound ROM, but GoldZone has only one, so there's just an empty socket here. I have seen games built on this board with two Sound ROM chips (Drill-O-Matic comes to mind)
And I just discovered something interesting on the reverse of the board:
U3 - A *giant* PLD! It needs 5V *and* 3.3V, which explains the use of a PC-AT power supply. Thankfully, the data pins of the DACs don't go anywhere near it.
Actually, on those data pins... it looks like they're running straight to the sound ROM! If I were to guess, they're driving the data pins of the DACs with the sound ROM itself, and mixing their analog outputs on the board before they go to the amps. So, a stuck sound could be caused by bad contact with the sound ROM, or an outright bad sound ROM! I'm gonna try reseating it and see if the problem goes away.
-E- After pulling out the sound ROM I noticed the socket is VERY green. I don't have a wire brush on hand, so I just reseated it and hoped for the best - no change. It seems to work fine except for the sound issue so I just turned the sound off and I'm running it like that for now. I'll revisit this tomorrow.
What I've figured out so far:
U1 - CPU, 80C32 clone, does pretty much everything, they even rely on the integrated RAM (there's no RAM chips here!)
U4 - Game program ROM, obviously.
U5 - EEPROM-SRAM hybrid NVRAM. It appears to use an external capacitor (U5C1) to power itself for a couple extra clicks so it can write SRAM out to EEPROM. Clever.
U301 - Sound ROM bank 1, again obvious.
U302 - Package of 4 mono DACs. More on this later.
U303 - Intended for a second Sound ROM, but GoldZone has only one, so there's just an empty socket here. I have seen games built on this board with two Sound ROM chips (Drill-O-Matic comes to mind)
And I just discovered something interesting on the reverse of the board:
U3 - A *giant* PLD! It needs 5V *and* 3.3V, which explains the use of a PC-AT power supply. Thankfully, the data pins of the DACs don't go anywhere near it.
Actually, on those data pins... it looks like they're running straight to the sound ROM! If I were to guess, they're driving the data pins of the DACs with the sound ROM itself, and mixing their analog outputs on the board before they go to the amps. So, a stuck sound could be caused by bad contact with the sound ROM, or an outright bad sound ROM! I'm gonna try reseating it and see if the problem goes away.
-E- After pulling out the sound ROM I noticed the socket is VERY green. I don't have a wire brush on hand, so I just reseated it and hoped for the best - no change. It seems to work fine except for the sound issue so I just turned the sound off and I'm running it like that for now. I'll revisit this tomorrow.