# Jawbreaker: an annotated Atari VCS disassembly that compiles to the exact ROM

> Tiger Electronic Toys' 1982 Atari VCS game Jawbreaker is disassembled into labeled and commented 6502 assembly that compiles to the exact ROM image. Notes explain how sprite positions are kept as combined fine-motion and coarse values and how an inverted playfield masks the maze, and record that joystick input is read from $0288 instead of SWCHA; assembler switches select an NTSC or PAL build and an optional no-defeat 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/jaw_breaker.asm>
- Primary source: <https://web.archive.org/web/20260222165051/https://www.qotile.net/minidig/disassembly/jaw_breaker.asm>
- Catalog page: <https://awesomerea.org/resources/jawbreaker-atari-vcs-disassembly-case/>
- Record JSON: <https://awesomerea.org/resources/jawbreaker-atari-vcs-disassembly-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/jawbreaker-atari-vcs-disassembly-case/index.md)

## Requirements & limits

- **Prerequisites:** Assembling needs a 6502 assembler and vcs.h version 105 or later.
- **Limits:** The author notes that the PAL version keeps the NTSC game speeds.
- **License:** No licence stated on the project page.

## Primary sources

1. <https://web.archive.org/web/20260222165051/https://www.qotile.net/minidig/disassembly/jaw_breaker.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.