C++ CHIP-8 Emulator

A work in progress

I am currently building a CHIP-8 emulator in C++. It is not finished yet, but I have already implemented the first six opcodes I decided to tackle, following the usual starting point for a project like this. Seeing those instructions work has made the project feel much more tangible: instead of only reading about emulation, I can write code, try it out, and watch parts of the system begin to work.

An opcode is an instruction that tells the emulated system what to do. The first six foundational opcodes I started with are 00E0 (clear the display), 1nnn (jump to an address), 2nnn (call a subroutine), 6xkk (set a register to a value), 7xkk (add a value to a register), and Annn (set the index register to an address). Implementing them has given me a first practical look at how a program can interpret instructions and reproduce their behaviour in software. Each opcode is another small piece of the overall system, and getting those pieces to fit together is a big part of what makes this project interesting to me.

Learning how emulation works

Before starting this project, emulation was something I wanted to understand better. Building an emulator myself has helped me move from the general idea to the practical work involved. I have learned a lot about emulation by thinking through what an instruction means, how to represent its effect in code, and how individual implementations contribute to a working emulator.

The project has also given me useful experience with C++. Rather than learning concepts in isolation, I can apply them while working toward a clear goal. When something does not behave as expected, I have to investigate the implementation and understand what the code is doing. That process has helped me become more comfortable with low-level programming and with solving problems step by step.

Right now, I am working on the opcode responsible for drawing graphics. It is considerably more complex than the first instructions I implemented, and I am currently a bit stuck on it. Even so, I am not giving up. I want to keep working through the problem, understand how the drawing instruction should behave, and get it working as part of my emulator.

Still more to build

There is still work to do before I can call the emulator complete. After making progress on the drawing opcode, I want to continue implementing and testing the remaining parts and make sure that the different pieces behave consistently together. For now, I am taking the project one step at a time: every challenge I work through gives me another opportunity to learn and brings the emulator a little closer to completion.

I am proud of the progress so far: I started this project to learn how emulators work, have implemented my first six opcodes, and am now taking on one of the more challenging parts. I am looking forward to continuing the development, learning from the difficulties along the way, and seeing the project grow into a more complete CHIP-8 emulator.