NitrOS-9 is a community-maintained distribution of Microware OS-9 for the Motorola 6809 and Hitachi 6309 processors. It supports the Tandy Color Computer family and several other 6809-based systems.

• level1/, level2/, and level3/ contain operating-system source arranged by OS level and target platform.
• defs/ contains shared assembler definitions.
• lib/ contains shared libraries.
• recipes/ contains the supported disk-image and distribution builds.
• scripts/ contains repository maintenance, formatting, and reverse-engineering utilities.
• archive/ preserves unsupported and historical material.

See Repository layout for details and Supported ports for the current target matrix.

Install the following tools and ensure they are on PATH:

• LWTOOLS, including lwasm, lwlink, and lwar
• ToolShed, including the os9 utilities
• make

Recipes that package BASIC09 require a sibling checkout of nitros9-languages. Some expanded recipes also use nitros9-apps:

parent/
  nitros9/
  nitros9-apps/
  nitros9-languages/

Set NITROS9_APPS_DIR or LANGUAGES to use another layout.

To build the CoCo 3 Level 2 floppy image:

export NITROS9DIR=$HOME/nitros9
make -C recipes/coco3/floppy

Each recipe writes its output into its own directory. See the recipe documentation for the available builds.

See CONTRIBUTING.md for contribution and commit guidance.

Historical release notes and migrated project files are retained under archive/project-history.