u/r2builder

Hello, I'm trying to better understand and reproduce the original arcade Pac-Man behaviour at a very granular level, and we’ve hit the limits of the usual publicly available explanations.

Only the "original" arcade Puck-Man derivatives.

There is plenty of good material about ghost personalities, scatter/chase timing, patterns, split-screen behavior, and general maze logic. What we’re missing is the really high-fidelity, frame-precise detail: the kind of information needed to verify behavior against the original hardware or produce an accurate simulation/tool-assisted analysis.

Specifically, i'm looking for information on things like:

- Exact per-frame update order

- Input sampling timing and buffering

- Pixel/tile position rules

- Movement speed changes per frame

- Pellet, energizer, fruit, and ghost-eating pauses

- Ghost decision timing at intersections

- Scatter/chase/frightened transition timing

- Reversal behavior and edge cases

- Tunnel movement timing

- Sprite/animation timing

- Any known hardware-specific quirks

- Differences between ROM sets, if relevant

In short: not “how does Pac-Man generally work?”, but “what exactly happens on each frame, and in what order?”

If anyone has preservation notes, disassembly commentary, MAME trace work, original PCB observations, timing captures, old forum posts, or personal research on this level of detail, we’d be very grateful. Even pointers to obscure documents or people who have worked on this before would be useful.

We’re especially interested in anything that helps distinguish emulator assumptions from verified original arcade behavior.

Thanks in advance. This is exactly the sort of thing where enthusiast and archivist knowledge may be better than anything indexed by search engines.