# Pitfall!: an annotated Atari VCS disassembly of scene generation and the kernel

> Activision's 1982 Atari VCS game Pitfall! is disassembled into labeled and commented 6502 assembly (version 0.9). Notes explain how a reversible LFSR generates the 255 jungle scenes, which bits of the random number select ground objects, scene type, tree pattern and wall position, and how the nine-stripe display kernel draws Harry, the liana, holes, ladder and wall; assembler switches add optional optimizations, screensaver code and a training mode.

- Type: Case study
- Targets: Game
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-09
- Added to the catalog: 2026-11-10
- Original resource: <https://www.qotile.net/minidig/disassembly/pitfall.asm>
- Primary source: <https://web.archive.org/web/20260213080644/https://www.qotile.net/minidig/disassembly/pitfall.asm>
- Catalog page: <https://awesomerea.org/resources/pitfall-atari-vcs-disassembly-case/>
- Record JSON: <https://awesomerea.org/resources/pitfall-atari-vcs-disassembly-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/pitfall-atari-vcs-disassembly-case/index.md)

## Requirements & limits

- **Prerequisites:** Assembling needs a 6502 assembler and the vcs.h Atari VCS header that the listing includes.
- **Limits:** Version 0.9 of the analysis, last updated in October 2001.
- **License:** No licence stated on the project page.

## Primary sources

1. <https://web.archive.org/web/20260213080644/https://www.qotile.net/minidig/disassembly/pitfall.asm>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.