NitrOS-9 is a community-based distribution of the Microware OS-9 operating system for the Motorola 6809 that was introduced in the late 1970s and sold into the 1980s.

The Hitachi 6309, which contains additional registers and enhanced instructions, is also supported.

Here are the current ports of NitrOS-9:

To build NitrOS-9, you need the following:

• lwtools. This package contains the required 6809 assembler and linker.
• ToolShed. ToolShed provides file system tools for creating disk images, copying files to and from those disk images, and more.

Once downloaded and installed, you can build the entire project:

export NITROS9DIR=$HOME/nitros9
make

The result is a number of disk images (ending in .dsk) that can be used on real floppy drives, emulators, and DriveWire.

If you wish to contribute, please fork the repository and submit pull requests.

Also, assembly source code is formatted to the following specifications:

• Spaces only (no tabs)
• Labels start at column 1
• Opcodes start at column 21
• Operands start at column 31
• Comments start at column 51

Put this file in your .git/hooks folder to ensure that any source code you submit is automatically formatted.