I'm currently in the process of highlighting this one. Transistors, vias, and about half of the diffusion layer have been marked so far. I've also identified a few of the "blocks" in it.
Just above the text in the lower-left is the clock circuitry and the horizontal counter, which is beneath it's vertical counterpart. In the upper-left corner are the score counters, and below that is the score display circuitry. These circuits have almost identical counterparts AY-3-8606 (score=lower-left,clock+counters=upper-right)
To the right of the upper score counter is the game select/rules PLA, and to the right of that *may* be a clock divider for the sound circuitry. I can't figure out what else is part of the sound system, other than the 12-bit LFSR in the upper-right of the die.
The lower right quadrant is interesting, it contains 7 shift registers setup as counters. Two of them are 9-bit, the rest are 7-bit. The 7-bit ones track the horizontal position of the 5 game objects (destroyer, cargo ship, sub, depth charge, torpedo), which means the 9-bit counters track vertical position. Wait, why are there only two VRT counters but 5 objects? Because the 3 boats are locked into a single VRT position, only able to move left/right but not up/down so they don't need VRT counters.
The pads have been labeled here (https://gitlab.com/TheProgrammerIncarnate/chip-processing/blob/master/GIgames/pinouts.jpg) Interestingly, the explosion sound and sonar sound have MUCH bigger driver transistors than all the other sounds for some reason (audible volume maybe?)
I'm currently in the process of highlighting this one. Transistors, vias, and about half of the diffusion layer have been marked so far. I've also identified a few of the "blocks" in it.
ReplyDeleteJust above the text in the lower-left is the clock circuitry and the horizontal counter, which is beneath it's vertical counterpart. In the upper-left corner are the score counters, and below that is the score display circuitry. These circuits have almost identical counterparts AY-3-8606 (score=lower-left,clock+counters=upper-right)
To the right of the upper score counter is the game select/rules PLA, and to the right of that *may* be a clock divider for the sound circuitry. I can't figure out what else is part of the sound system, other than the 12-bit LFSR in the upper-right of the die.
The lower right quadrant is interesting, it contains 7 shift registers setup as counters. Two of them are 9-bit, the rest are 7-bit. The 7-bit ones track the horizontal position of the 5 game objects (destroyer, cargo ship, sub, depth charge, torpedo), which means the 9-bit counters track vertical position. Wait, why are there only two VRT counters but 5 objects? Because the 3 boats are locked into a single VRT position, only able to move left/right but not up/down so they don't need VRT counters.
The pads have been labeled here (https://gitlab.com/TheProgrammerIncarnate/chip-processing/blob/master/GIgames/pinouts.jpg) Interestingly, the explosion sound and sonar sound have MUCH bigger driver transistors than all the other sounds for some reason (audible volume maybe?)
Simulated it! https://nerdstuffbycole.blogspot.com/2019/10/shooter-game-in-silicon-inside-ay-3.html
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