Thomson MO5 C Examples (CMOC-based)

This repository contains a collection of C language examples for the Thomson MO5, built with the CMOC compiler and related tools.

The project explores different approaches to C development on the MO5, ranging from pure CMOC usage to hybrid and fully home-made C libraries.

All projects are built using Makefiles, available at multiple levels of the repository.

Prerequisites

To build and run the programs, you will need:

• DCMOTO emulator
  http://dcmoto.free.fr/emulateur/index.html

• LWTOOLS (6809/6309 cross-development tools)
  https://www.lwtools.ca/

• CMOC (Motorola 6809 C compiler)
  http://gvlsywt.cluster051.hosting.ovh.net/dev/cmoc.html

⚠️ Note: Some of these websites use HTTP instead of HTTPS.
They are well-known and trusted resources in the retro-computing community.

Project Structure

.
├── Makefile                  # Root Makefile (builds everything)
├── tools/
│   └── BootFloppyDisk/       # BootFloppyDisk tools
├── cmoc-native/
│   ├── Makefile              # Builds all samples
│   ├── key_reader/
│   │   ├── Makefile
│   │   └── src/
│   │       └── main.c
│   └── what_is_your_name/
│       ├── Makefile
│       └── src/
│           └── main.c
├── cmoc-hybrid/
│   ├── Makefile              # Builds all samples
│   ├── libs/
│   ├── key_reader/
│   │   ├── Makefile
│   │   └── src/
│   │       └── main.c
│   ├── what_is_your_name/
│   │   ├── Makefile
│   │   └── src/
│   │       └── main.c
│   └── fusee/
│       ├── Makefile
│       └── src/
│           └── main.c
├── home-made/
│   ├── Makefile              # Builds all samples
│   ├── libs/
│   ├── key_reader/
│   │   ├── Makefile
│   │   └── src/
│   │       └── main.c
│   └── what_is_your_name/
│       ├── Makefile
│       └── src/
│           └── main.c
└── graphic/
    ├── Makefile              # Builds all samples
    ├── libs/
    ├── display_text/
    │   ├── Makefile
    │   └── src/
    │       └── main.c
    └── hello_word/
        ├── Makefile
        └── src/
            └── main.c

BootFloppyDisk Installation

The root Makefile can automatically install BootFloppyDisk, which is required to generate bootable disk images for the Thomson MO5.

To install the tools:

make install

This will:

• Clone the BootFloppyDisk repository
• Build the required tools
• Generate BOOTMO.BIN, used during disk image creation

Building the Projects

Build everything (root level)

make

Build per directory

Each main directory contains its own Makefile, allowing you to build only the samples inside that directory.

Example:

cd cmoc-native
make

Build a single sample

Each sample directory has its own Makefile and a single entry point located in src/main.c.

Example:

cd cmoc-native/key_reader
make

Clean build files

Clean everything from the root:

make clean

Or clean at directory or sample level using the corresponding Makefile.

Directory Overview

cmoc-native

• Uses only cmoc.h
• No standard C libraries
• Pure CMOC examples

cmoc-hybrid

• Uses cmoc.h
• Adds custom libraries to extend missing C features
• Partial implementations of stdio.h and ctype.h

Libraries are located in cmoc-hybrid/libs.

home-made

• Does not use cmoc.h
• Fully home-made implementations of stdio.h, ctype.h and string.h

Libraries are located in home-made/libs.

graphic

• Use cmoc.h
• Explore graphic features

Sample Projects

Each directory (cmoc-native, cmoc-hybrid, home-made) contains the same two sample projects.

what_is_your_name — Name Greeting Program

• Prompts the user to enter their name
• Displays:

Hello [entered name]

key_reader — Key Code Display Program

• Waits for a key press
• Displays the character code of the pressed key

fusee (cmoc-hybrid only) — text rocket game

• move a rocket (A caracter)
• fuel management

Goals of This Repository

• Explore C programming on the Thomson MO5
• Compare multiple development approaches:
  • CMOC-only
  • CMOC + extended libraries
  • Fully custom C runtime
• Provide small, clear, and educational examples

References

Detailed explanations about the development environment and toolchain setup used in this project are available on my blog:

• Toolchain and environment setup (DCMOTO, LWTOOLS, CMOC, BootFloppyDisk):
  https://thlg057.github.io/mo5-blog/en/days/day-1-setup/

This article explains step by step how to install and configure the tools required to build and run the examples provided in this repository.

Credits

• BootFloppyDisk tools by OlivierP-To8
• Thomson MO5 community and documentation