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channelmaniac

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Hey folks,

Had a bit of a bitch of a Crime City on the bench. Two stuck inputs and a sound subsystem in watchdog. Fixed it, but in the midst of doing that I reversed the pinouts for two of the customs:

TC0220IOC - I/O Controller IC
TC0140SYT - Sound Subsystem Controller IC

The I/O controller handles DIP switch and control switch input, coin lockout and counter outputs, and master /RESET signal for the game.

The Sound Subsystem Controller handles memory decoding, /RESET for the sound subsystem, watchdog for the sound subsystem, and communications between the main and sound CPUs.

Taito TC0220IOC.jpg



Taito TC0140SYT.png
 
Is there some explanation somewhere about these pins? Pin 5 and 7 on the tc0220ioc is why i'm asking.
 
These are pins from the PALs to the chip on Crime City. I'm thinking one (pin 5) would be for a /CS (Chip Select) or similar function for accessing the I/O chip as that's an output on the GAL.

Pin 11 is an input so it is possibly an /INT (interrupt) coming from the I/O chip.

I haven't taken any time to do any specific logic analysis and don't really plan to.
 
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