78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
package emulator
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import "errors"
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type CHIP8 struct {
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memory [4096]byte
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v [16]byte
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i uint16
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pc uint16
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sp uint16
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delayTimer uint8
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soundTimer uint8
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stack [16]uint16
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keypad [16]bool
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// To transform the linear Memory to a 2D array for easier drawing,
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// having a (x, y) coordinate then (x, y) = graphics[x + (y * 64)]
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graphics [64 * 32]bool
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opcode uint16
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fonts [80]byte
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}
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func NewChip8() *CHIP8 {
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chip8 := &CHIP8{
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memory: [4096]byte{},
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v: [16]byte{},
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i: 0,
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// The original 0x200 code of the CHIP-8 interpreter was from 0x0 to 0x200,
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pc: 0x200,
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sp: 0,
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delayTimer: 0,
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soundTimer: 0,
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stack: [16]uint16{},
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keypad: [16]bool{},
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graphics: [64 * 32]bool{},
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opcode: 0,
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fonts: [80]byte{},
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}
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chip8.Initialize()
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return chip8
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}
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func (c *CHIP8) Initialize() {
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charMap := [80]byte{
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0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
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0x20, 0x60, 0x20, 0x20, 0x70, // 1
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0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
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0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
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0x90, 0x90, 0xF0, 0x10, 0x10, // 4
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0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
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0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
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0xF0, 0x10, 0x20, 0x40, 0x40, // 7
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0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
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0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
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0xF0, 0x90, 0xF0, 0x90, 0x90, // A
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0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
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0xF0, 0x80, 0x80, 0x80, 0xF0, // C
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0xE0, 0x90, 0x90, 0x90, 0xE0, // D
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0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
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0xF0, 0x80, 0xF0, 0x80, 0x80, // F
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}
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// Char map goes from 0x050 to 0x9F
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for i, charByte := range charMap {
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c.memory[i+0x50] = charByte
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}
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}
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func (c *CHIP8) LoadROMIntoMemory(dat []byte) error {
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if len(dat) > len(c.memory)-0x200 {
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return errors.New("ROM is too large to fit into memory")
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}
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// Roms start from 0x200
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for i, datByte := range dat {
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c.memory[i+0x200] = datByte
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}
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return nil
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}
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