chemu

Chemu is a CHIP-8 emulator that is written in C and uses the SDL2 library.

Usage

Using chemu is very easy, you only need to specify the (CHIP-8) rom you want to run. E.g. chemu rom.ch8

Keybindings

CHIP-8 uses a hex keyboard. This means that input is done with the 0-9 and A-F keys on your keyboard.

Installation

To install this program you must simply run make install which will install it to the $(PREFIX)/bin/ directory.

Current progress

Chemu, is still very early in development. Some games may not work perfectly (such as tetris) but most games should be working. I still don't know why some of these games don't work but in the coming days these bugs should be fixed.

• All CHIP-8 instructions/opcodes emulated

  • All CHIP-8 games working

• All SCHIP instructions/opcodes emulated

  • All SCHIP games working

• Configurable keyboard layout

• Simple graphical debugger

What is CHIP-8

"CHIP-8 is an interpreted programming language, developed by Joseph Weisbecker. (...) CHIP-8 programs are run on a CHIP-8 virtual machine."

--Wikipedia EN: CHIP-8

As Wikipedia explains, CHIP-8 is an interpreted programming language which runs on a virtual machine. CHIP-8 is usually implemented as an emulator, though some pure hardware implementations also exist.

The CHIP-8 virtual machine consists of:

• four kilobytes of memory
• 16 8-bit general purpose registers V0-VF
  • VF is also used as a status register
• An index register (I)
• a simple stack which stores return addresses
  • This stack uses a special stack pointer register that isn't directly accessible to the user
• a delay and sound timer
  • when the sound timer is not zero it makes a beeping sound
• a 64 x 32 resolution monochrome screen
• 35 opcodes
• hex keyboard input

Why make a CHIP-8 emulator

Though creating a CHIP-8 emulator is not very practical, CHIP-8 is a great system to start learning about emulation and generally learning about computer hardware..

Things you may learn when making a CHIP-8 emulator are:

• The basics of emulation
• Key concepts in computing
  • Timers
  • Stacks
  • Registers
  • Memory
  • How are subroutines called

Even though CHIP-8 was never used on anything (on a real computer or console) it still has a suprising amount of games ported to it such as Pong, Tetris, Space Invaders, etc.