Everything you ever wanted to know about Pac-Man, but were afraid to ask

The Pac-Man Dossier

Everything you ever wanted to know about Pac-Man, but were afraid to ask

The original Pac-Man arcade game might be pushing 32 years of age, but the name still has interest with video game fans of all generations.  Pac-champ David Race once again made international headlines when RecordSetter announced he’d set another new speed record while the recent online World’s Biggest Pac-Man game estimates more than 40 man-hours have been played on their website in the past year.

Casual players and observers who think there isn’t much to Pac-Man strategy and gameplay might be surprised by a visit to the Pac-Man Dossier website.  This labor of love by dot gobbling fan Jamey Pittman goes deep into the Pac-Man program, explaining not only strategies but how the game thinks and reacts to the player’s every move.

“As a kid, my grandparents would often take me to a local shopping mall that had a Gold Rush arcade,” Pittman recalled. “This is where I encountered my first Pac-Man machine in 1980 or 1981. Up to that point, I had dropped most of my quarters into space-themed, ‘shoot ’em up’ titles like Space Invaders and Asteroids, but that all changed once I saw Pac-Man.  Everything about it seemed so new and different compared to what I was used to: the cabinet, the colorful characters, the sounds, everything.”

Decades later, Pittman once again returned to the deep blue maze.

[youtube]http://www.youtube.com/watch?v=JLfugsoU3d0[/youtube]

“The game studio I was a software developer for went under in 2008, and I suddenly found myself with a lot of time on my hands,” he said. “I started playing a lot of Pac-Man using the MAME emulator and realized that, as much as I enjoy playing Pac-Man, it would be even more fun to reverse engineer the game and finally learn how the ghosts work ‘under the hood’, so to speak. So I set out to fill in the many gaps in the internet’s collective knowledge base on the inner workings of Pac-Man. The goal was to conclusively prove how every part of the game functioned, especially everything related to ghost behavior, and put everything I learned into one reference document to share with interested parties.”

With input from several Pac-Man champs and classic arcade reverse-engineering guru Don Hodges, Pittman completed the Dossier after two months of work.  With explanations on every aspect of Pac-Man from how the monsters react to player movements to why and how the player can sometimes pass through an enemy without losing a life, Pittman notes a few programming bugs in particular that caught his eye.

“I think one of the more interesting tidbits was how the chase mode logic for Pinky and Inky works slightly differently when Pac-Man is facing upward,” he said. “After noticing this subtle discrepancy in Pinky’s targeting algorithm, Don and I did some additional code analysis and concluded the game developers screwed up by leaving an overflow bug in the code used for calculating tile offsets relative to Pac-Man’s current position. Another interesting bug I uncovered is how to trap three of the ghosts inside their home during the first two levels of play. That one took some time to figure out as the code governing when and how ghosts leave their home is fairly convoluted.”

Since launching, the Pac-Man Dossier has received hits from over 300,000 unique visitors and was even used as a learning tool when Google developed their popular Pac-Man 30th Anniversary Doodle in 2010.  If time allows, Pittman says he may do similar site for another arcade classic.

“I could easily do an sister site on Ms. Pac-Man as it’s based on the original Pac-Man code,” he said.  “Both I and Don have already spent a lot of time looking over that game’s disassembled code.  But in terms of choosing a completely different title, I think I would most enjoy tearing Centipede completely apart. Defenderor Joust would be fun projects as well.”

The Pac-Man Dossier can be visited by clicking here.

Patrick Scott Patterson has been a gamer since 1981, acting as a writer, technician and world record holder on several game titles. He has appeared numerous times in the yearly editions of Guinness World Records: Gamer’s Edition. In addition to writing here, Patterson has also written for Yahoo!, Twin Galaxies, VGEVO and Gameroom Magazine, and is always looking for unique and positive news to report from the video gaming world.

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Patrick Scott Patterson

Patrick Scott Patterson (Scott or his gaming handle "OriginalPSP") has been gaming since 1981. A multiple-time video game world record holder as recognized by three organizations, Scott aims to help promote the fun and positive side of both past and present video game culture through this articles here and his official website at PatrickScottPatterson.com.