chip-8-emulator

A CHIP-8 Emulator in Kotlin Multiplatform targeting the JVM and JS

https://lpicanco.github.io/chip-8-emulator/

Implemented Opcodes

Instruction	Description
00E0	Clears the screen
00EE	Returns from a subroutine
1NNN	Jumps to address NNN
2NNN	Calls subroutine at NNN
3XNN	Skips the next instruction if VX equals NN
4XNN	Skips the next instruction if VX doesn't equal NN
5XY0	Skips the next instruction if VX equals VY
6XNN	Sets VX to NN
7XNN	Adds NN to VX without changing the carry flag
8XY0	Sets VX to the value of VY
8XY1	Sets VX to VX OR VY
8XY2	Sets VX to VX AND VY
8XY3	Sets VX to VX XOR VY
8XY4	Adds VY to VX. VF is set to 1 when there's a carry, and to 0 when there isn't
8XY5	VY is subtracted from VX. VF is set to 0 when there's a borrow, and 1 when there isn't
8XY6	Stores the least significant bit of VX in VF and then shifts VX to the right by 1
8XY7	Sets VX to VY minus VX. VF is set to 0 when there's a borrow, and 1 when there isn't
8XYE	Stores the most significant bit of VX in VF and then shifts VX to the left by 1
9XY0	Skips the next instruction if VX doesn't equal VY
ANNN	Sets I to the address NNN
BNNN	Jumps to the address NNN plus V0
CXNN	Sets VX to the result of a bitwise and operation on a random number (Typically: 0 to 255) and NN
DXYN	Draws a sprite at coordinate (VX, VY) that has a width of 8 pixels and a height of N+1 pixels. Each row of 8 pixels is read as bit-coded starting from memory location I; I value doesn’t change after the execution of this instruction. As described above, VF is set to 1 if any screen pixels are flipped from set to unset when the sprite is drawn, and to 0 if that doesn't happen
EX9E	Skips the next instruction if the key stored in VX is pressed
EXA1	Skips the next instruction if the key stored in VX isn't pressed
FX07	Sets VX to the value of the delay timer
FX0A	A key press is awaited, and then stored in VX. (Blocking Operation. All instruction halted until next key event)
FX15	Sets the delay timer to VX
FX18	Sets the sound timer to VX
FX1E	Adds VX to I. VF is not affected
FX29	Sets I to the location of the sprite for the character in VX. Characters 0-F (in hexadecimal) are represented by a 4x5 font
FX33	Stores the binary-coded decimal representation of VX, with the most significant of three digits at the address in I, the middle digit at I plus 1, and the least significant digit at I plus 2
FX55	Stores V0 to VX (including VX) in memory starting at address I. The offset from I is increased by 1 for each value written, but I itself is left unmodified
FX65	Fills V0 to VX (including VX) with values from memory starting at address I. The offset from I is increased by 1 for each value written, but I itself is left unmodified