memu

Emulators written in Rust and reusable abstractions for their implementations.

This is a hobby project where I explore writing simple emulators in rust. The goal is twofold:

• Become familiar with Rust
• Dip my toes in Emulator development

To do this, I decided to build emulators for various devices, starting with a CHIP 8 emulator. Ideally, some of the abstractions created for this purpose can be reused for a future emulator.

Since I am using this code mainly as a way to mess around with Rust do not expect idiomatic code here. Do expect a lot of overengineering as I figure out what I can and cannot do with Rust.

Details about a given emulator can be found in src/<name of emulator>.

Current Status

Currently, memu can emulate the chip8 system, albeit without sound. Not that many roms were tested, so expect some bugs.

Build / Installation

Fetch the code, and use cargo to build and run it:

• git clone https://github.com/mathsaey/memu.git
• cd memu
• cargo run

If you're so inclined, you can use cargo install --path . to install memu.

Use

To use memu, call it with an emulator name and a path to a rom for that emulator: memu <emulator> <rom-path>. To use your terminal as a debug view, pass the -D flag; for a full list of options, use memu --help. If you are using cargo run, replace memu with cargo run --.

Once the emulator is running, use <esc> to close it.

Emulation modes

memu supports 3 different emulation modes:

• cycle: In cycle mode, the emulator executes a single instruction every time <space> is pressed. The emulator will start in cycle mode if the debug view is enabled (-D). Pressing / will change the emulator to frame mode.
• frame: In frame mode, pressing <space> will make the emulator execute instructions until a redraw is required. Pressing / will put you in normal mode.
• normal: In this mode, the emulator runs at its normal speed. Pressing < or > will slow down or speed up the emulation speed, respectively. Press / to change to cycle mode. Emulation starts in this mode if the debug view is not enabled.

(Non) Goals

As this is a hobby project, I'm using this project as an excuse to mess with various things such as:

• Emulation
  • Simple, reasonably efficient chip 8 emulator
• Non-Functional goals
  • Reusable components to use for additional emulators
  • A TUI interface that shows the internals of the system that is being emulated.

For the same reason I am not focusing on the following requirements:

• Perfect emulation
• Hyper-optimized code