How to Put Gameboy Components in A Calculator

Introduction

Combining Game Boy components with a calculator offers a unique way to explore digital electronics and computing principles. The Game Boy's CPU, memory chips, and display controller can be adapted to work with a calculator's input/output system, creating a hybrid device that performs both calculations and retro gaming functions.

This project requires basic soldering skills and knowledge of digital electronics. The calculator's original circuit must be modified to accommodate the Game Boy components while maintaining the calculator's core functionality.

Game Boy Components

The key components from a Game Boy that can be integrated into a calculator include:

• CPU (Sharp LR35902): The Game Boy's CPU can be used to execute game logic when the calculator is in gaming mode.
• ROM Cartridges: Game ROMs can be loaded into the calculator to store game data.
• LCD Controller (Sharp SPC700): The Game Boy's LCD controller can be adapted to drive the calculator's display.
• Memory Chips (RAM, VRAM): These provide working memory for the calculator's operations.
• Buttons and D-Pad: The Game Boy's input components can be repurposed for calculator functions.

Assembly Process

Step 1: Prepare the Calculator

Begin by disassembling the calculator to access the main circuit board. Identify key components such as the display, buttons, and power supply. Remove or disable the original calculator circuit to avoid interference with the Game Boy components.

Step 2: Select Compatible Components

Choose Game Boy components that operate at the same voltage as the calculator (typically 5V). Some components may need voltage regulators to ensure compatibility.

Step 3: Design the Interface Circuit

Create a custom interface circuit that connects the Game Boy components to the calculator's bus. This may involve level shifters, buffers, and additional logic to manage data flow between the two systems.

Step 4: Assemble the Circuit

Solder the Game Boy components onto the calculator's circuit board according to your design. Pay close attention to power connections and signal paths to ensure proper operation.

Step 5: Test and Debug

Power on the calculator and test each Game Boy component individually. Use a multimeter and oscilloscope to troubleshoot any issues with signal levels or timing.

Compatibility Notes

Not all Game Boy components will work seamlessly with a calculator. Consider the following compatibility factors:

• Voltage Levels: Ensure all components operate at the same voltage or use level shifters.
• Clock Speed: The calculator's clock speed may need adjustment to match the Game Boy's requirements.
• Memory Mapping: The calculator's memory map must be modified to accommodate the Game Boy's ROM and RAM.
• Display Interface: The Game Boy's LCD controller may require a custom driver to work with the calculator's display.

Worked Examples

Example 1: Basic Calculator Mode

When the calculator is in its standard mode, the Game Boy components remain inactive. The calculator performs its normal arithmetic functions.

Example 2: Gaming Mode

When the calculator is switched to gaming mode, the Game Boy CPU takes control of the display and input systems. The calculator's buttons are repurposed as Game Boy controls, and the display shows the game screen.