The autopsy

Games taken apart by running them: every routine a game entered, the patterns in its code, its tables and its memory, written down as a listing that assembles back to the cartridge.

We wanted to learn how the old games were written by starting at the beginning: take one apart, see what every piece of it does, and write that down in a form we can check. The trouble with a cartridge is that code and data sit in it side by side with nothing to say which is which. So we run the game. What the processor fetched as an instruction is code, and what a routine did while it ran says what the routine is for.

Four steps, in order

1. Decompile: The cartridge becomes a listing: assembly a person can read, with marks in its comments for everything we learned. The check is simple and strict: the file assembles back to the cartridge, byte for byte.
2. Crawl: A program plays the game on our own console, trying the buttons from every position it has reached and keeping the ones that ran code nothing had run before.
3. Identify: Rules read what each routine did while it ran and name the ones they recognise: the one that reads the controller, the one that chooses the game's state, the ones that draw the sprites.
4. Label: The names go back into the listing, where a person can read them, correct them and add their own. The Listing window on the desk writes one for any run you record.

Where to look

• The games: Every cartridge on our shelf after the same treatment: how much of its program ran, the routines it entered, and the patterns found in it.
• The patterns: The things games keep doing, each named by a rule over what the code did while it ran, and how many games each was found in.
• How it is done: The listing, the crawl, the rules and the model: what each step does, what it cannot see, and what stays on our own machine.

Where it stands

The first survey went over 19 cartridges from our own shelf, 400 steps of crawling each, starting cold at power-on. It entered 2,933 routines and put 557 pattern names on them. That much crawling reaches a small part of a big game, 7 percent of the program bytes across the shelf, so every count here is a floor. It was recorded on 2026-10-01.

No page here holds a byte of anybody's game

The listings stay on the machine that holds the cartridges. What is published is shape: addresses, counts and the names of patterns. A routine no rule recognised is listed without a name rather than given a guess.

The patterns are a toolkit's table of contents

What recurs across games is what a person writing a new one needs at hand. The toolkit built from these patterns, and a studio in the browser for writing games with it, come after this groundwork and are not built yet.