This Chip-8 emulator is implemented in C, leveraging the RayLib library for graphical and input handling capabilities.

• Introduction
• Getting Started
• Usage
• Technical Implementation
• Screenshots
• License

Chip-8 is a simple, interpreted, programming language which was first used on some do-it-yourself computer systems in the late 1970s and early 1980s.

The Chip-8 Emulator project is my way of paying homage to early video games and learning more about how computers work. Chip-8 is an old and basic computer system from the late 1970s and early 1980s. It was used for simple games and programs on early computers.

I decided to create this emulator to have fun and to understand the basics of computer systems. Making the Chip-8 games run on modern computers helps us appreciate the history of gaming and how computers have evolved. During this project, I've learned about how computer instructions are translated, how memory works, and how pictures are drawn on the screen.

Along this project I have learned a lot including but not limited to:

• Writing and understanding a 8-bit and 16-bit hex dump
• How to disassemble and decode an opcode into instructions a CPU can use
• How a CPU can utilize memory, stack, program counters, stack pointers, memory addresses, and registers
• How a CPU implements fetch, decode, and execute

I hope my version of the Chip-8 emulator can easy to easily understood by beginners, as I have tried my outmost effort to write easy-to-understand code, and for this is the reason for me deciding to utilize RayLib, as it's an easy graphical library.

To be able to build the emulator you will need to install RayLib.

git clone https://github.com/khaledmust/chip-8-emulator.git

cd chip-8-emulator

make

./output ./roms/ROM_NAME

The Chip-8 keypad has been mapped to the following keys:

Keypad                   Keyboard
+-+-+-+-+                +-+-+-+-+
|1|2|3|C|                |1|2|3|4|
+-+-+-+-+                +-+-+-+-+
|4|5|6|D|                |Q|W|E|R|
+-+-+-+-+       =>       +-+-+-+-+
|7|8|9|E|                |A|S|D|F|
+-+-+-+-+                +-+-+-+-+
|A|0|B|F|                |Z|X|C|V|
+-+-+-+-+                +-+-+-+-+

The Chip-8 has 36 different instructions, including math, graphics, and flow control functions. All the instructions are 2-bytes long and are stored in the most-significant-byte first.

All those instructions are implemented in the chip8.c file.

The emulator starts by calling chip8_parse_code function, this function first parses 8-bits of opcode and then increment the PC to point to the next 8-bits opcode which is thenOR to the previous one to form 16-bits instruction.

Then the function chip8_inst_emulate is called which executes the opcode by first, calling an array of function pointer, then, executing the function the corresponds to the extracted nibble from the opcode.

This project is open source and available under the MIT License.