CHIP-8

A CHIP-8 emulator/interpreter written in C++ with SDL3

This is a CHIP-8 emulator with Dear ImGui setup on top of SDL for the rendering, and as such a menu is provided to customize a few things within the emulator itself.

Roadmap

• Upgrade to SDL3
• Open file dialog must not pause the entire app
• Add an option to have "normal" key system
• Add Sound
• Implement other CHIP-8 versions

QnA

Where is the sound?

Not implemented yet!

Why won't [game] run / Why is [game] not working properly?

Only the CHIP-8 instructions are implemented, meaning anything specific to other versions may not work properly.
If you think/know your game should run on CHIP-8, then try switching to the "CHIP-8" preset in settings.

Despite the different modes, not all tests pass on [testing rom]

While I can't try all testing ROMs, I did try to pass what i could on the test suite.
However, there are a few intentional failures on that rom:

• Keypad test -> FX0A GETKEY will say NOT RELEASED - See the next question. I am not planning to fix this.
• Quirks -> CHIP-8 will (with the CHIP-8 preset) pass everything except DISP.WAIT. I am not planning to fix this.
• Quirks -> XO-CHIP will (with the XO-CHIP preset) pass everything except CLIPPING. I am planning to fix this.

Why is the key input not how it was on CHIP-8 systems?

Because i find having to release keys for them to register is very confusing as a user, so i decided to send the input whenever the key is just pressed.
This results in the test suite saying "not released" in the keypad test.
Additionally, the input system (intentionally) only supports one input at once.

Why can't i remap my keys?

Again, this isn't implemented yet. default key placement on a QWERTY keyboard is as follows:

Keys     |  QWERTY   |  AZERTY
1 2 3 C  |  1 2 3 4  |  & é " '
4 5 6 D  |  Q W E R  |  A Z E R
7 8 9 E  |  A S D F  |  Q S D F
A 0 B F  |  Z X C V  |  W X C V

Note that this is based on key position, and not on key label, so e.g. QWERTZ and DVORAK users wouldn't have to reach across their keyboards.

Libraries used

SDL3 by the libsdl organization
Dear ImGui by ocornut
tinyfiledialogs by vareille
libconfig by hyperrealm