The "No-CPU Amiga Demo Challenge" is an open competition to create demos that run entirely on Amiga custom chips without involving the CPU. This GitHub repository hosts the challenge rules and a "runner" application used to launch no-CPU demos, establishing a standard platform for such demos. Key points: - There will be a dedicated no-CPU Amiga demo competition at Gerp 2026 (Jan 23-25, 2026). - An invitation demo was released at Evoke 2025, with source code available. - Participants are encouraged to announce their no-CPU demos via an issue in the repository. - A FAQ is available within the repo. Background: The Amiga's custom chips (Alice, Lisa, Paula) have powerful graphic and audio capabilities that traditionally complemented a modest CPU. This challenge explores the potential of these chips operating independently of the CPU. Similar technical-themed demo competitions have been held for platforms like Atari and Commodore 64. Technical details: - A no-CPU demo is a raw memory image specifying chip memory contents plus a defined initial hardware register state. - The image is loaded by the official runner; demos must be compatible with this runner. - Maximum image size depends on chipset (512k OCS, 1MB ECS, 2MB AGA). - Audio filter disabled (controlled by CIA registers inaccessible by the copper). - Initial hardware register values are set with OCS defaults for ECS/AGA compatibility. - The demo can signal completion by clearing the Blitter Nasty flag, though the runner may not exit to OS, so a valid display should persist. Feedback: Issues or comments can be raised via GitHub issues. The repository maintainer is particularly interested in feedback about: - Any limits the rules or runner place on no-CPU demo capabilities. - Potential security issues in the runner that could enable CPU reactivation. Repository details: - Public repository owned by user "askeksa" named "NoCpuChallenge". - Contains folders like "runner" and documents including LICENSE.txt and README.md. - Licensed under the Zlib license. - Written entirely in Assembly language. - The repo currently has 24 stars, 0 forks, and 4 open issues. - No releases or packages published yet. - Links and descriptions provided for rules, runner, invite demo, and competition dates. This challenge invites exploration of a unique demo programming approach on Amiga hardware, focusing on the chip's potential independent of its CPU.