🕹️⌨️ The KeyPortari a 2600/7800 Keyboard Interface

This project enables the connection of a PS/2 keyboard (or a USB keyboard that supports the PS/2 protocol) to the Atari 2600 or 7800 console. The ATmega328P processes keystrokes and controls the joystick inputs of the Atari 2600 accordingly.

✨ Features

• PS/2 Keyboard Support: Supports various keyboard layouts (DE, US, FR).
• Direct ASCII Conversion: Translates keystrokes into Atari 2600-compatible signals.
• Configurable Keymaps: Customizable key assignments for Atari 2600 control.
• Efficient GPIO Usage: Utilizes an 8-bit port for direct control.
• Configurable DIP Switches: 4-bit resistor-ladder circuit for easy configuration.

🔌 Hardware Requirements

• ATmega328P 5V 16Mhz (Arduino-compatible)
• PS/2 Keyboard (or USB Keyboard that supports the PS/2 protocol)
• Resistors for Resistor-Ladder (10kΩ, 20kΩ, 40kΩ, 80kΩ, 100kΩ Pull-up)
• 2x Quad analog switch (74HC4066)
• Joystick port connection for the Atari 2600

🛠️ Sponsored by JLCPCB

PCB manufacturing for this project was kindly sponsored by JLCPCB – a leading PCB prototype service. For the first prototype run, JLCPCB generously provided 15 SMD assembled test boards, helping to accelerate early hardware development.

If you’re a developer or hardware tinkerer and would like to experiment with the interface or contribute your own ideas, feel free to reach out to me via AtariAge – I’d be happy to provide a board to support your work.

🧪 Breadboard Setup (one joystick forwarded)

⚙️ Installation & Setup

1. Upload code to ATmega328P (via Arduino IDE or AVRDUDE).
2. Connect PS/2 keyboard to the corresponding pins.
3. Set DIP switches for the desired configuration.
4. Connect to the Atari 2600 joystick port.

🎮 Usage

• Each keystroke on the PS/2 keyboard is translated into joystick controls for the Atari 2600.
• Modifier keys like Shift, Ctrl, and Alt influence the key output (e.g., uppercase/lowercase characters).
• DIP switches can be used to activate different keyboard layout (US,DE,FR) configurations.

🐞 Known Issues & Solutions

🙏 Credits

• Project discussion: AtariAge Forum
• Open-source libraries: PS/2 Keyboard Library (modified for this project)
• Steve Guidi's "Basic Programming" protocol

📄 License

• Firmware is licensed under the MIT License
• Hardware designs (schematics, PCB) are under the CERN Open Hardware Licence v2.0 - Permissive

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If you have any questions or suggestions, feel free to open an issue on GitHub! 🎮