CHIP8 Emulator

A CHIP8 emulator written in rust.

Building

Make sure you have the latest version of Rust.

cargo build

Troubleshooting

If you're running linux, you may need to install libwayland-dev

Running

This emulator reads binary files written with chip8 operations. A program might look something like this:

hexdump testbin/xy_neq_neq.chip8
0000000 0560 0661 1090 0170
0000008

The testbin folder has several examples of chip8 programs for each instruction.

To run a program, use the load operation followed by the file you wish to load:

chip_8_emulator load myChip8Prog.chip8

colors

An optional arg can be used to set the color for the pixels, purple, green, blue, or red, the default is purple.

chip_8_emulator load myChip8Prog.chip8 blue

Keyboard

The CHIP8 keyboard:

1	2	3	c
4	5	6	d
7	8	9	e
a	0	b	f

Is mapped to:

1	2	3	4
q	w	e	r
a	s	d	f
z	x	c	v

Testing

cargo test

Writing a program

Drawing

row	op	op	Description
0x200	A2	06	Set our address register to begin reading at location 206
0x202	D0	05	Draw at (0,0), 5 bytes starting from the location in memory specified by the address register
0x204	00	00	Halt
0x206	FF	C3	The bytes that will be drawn
0x208	FF	C3
0x210	00

Note that programs loaded into memory begin at location 0x200, this is the default in some CHIP8 machines, though not all of them

each pixel cooresponds to a set bit

// ******** 0xFF 0b1111_1111
// **    ** 0xC3 0b1100_0011
// ******** 0xFF 0b1111_1111
// **    ** 0xC3 0b1100_0011
// **    ** 0xC3 0b1100_0011

cargo build
./target/debug/chip_8_emulator load examples/draw_a.chip8

Debugging

Debugging allows you to wait for enter, esc, or delete to be pressed before the next operation is executed.

• ENTER -> Proceeds to next instruction
• ESC -> Exits the emulator
• DELETE -> Resumes normal execution",

cargo build
./target/debug/chip_8_emulator debug examples/a_plus_a.chip8

Future Features

• Rewind
• Window size CLI param
• Print the ops of a program out with a description
• Second window for state in debug mode
• Displaying last op, next op in debug