Public
Edited
Oct 20, 2023
registers
function makeCpuRegisters() {
const registers = {
SP: 0,
PC: 0
}
const splitRegisters = ['AF', 'BC', 'DE', 'HL']
splitRegisters.forEach(pair => {
const [hi, lo] = pair
registers[hi] = 0
if (lo === 'F') {
Object.defineProperty(registers, 'lo', {
value: 0,
enumerable: false
})
} else {
registers[lo] = 0
}
Object.defineProperty(registers, pair, {
get() {
return this[hi] << 8 | this[lo]
},
set(value) {
this[hi] = (value & 0xFF00) >> 8
this[lo] = value & 0xFF
},
enumerable: true
})
})
const flags = ['z', 'n', 'h', 'c']
flags.forEach((flag, index) => {
const bit = 1 << (7 - index)
Object.defineProperty(registers, flag, {
get() {
console.log(flag, bit.toString(2), this.F & bit, this.F & bit ? true : false)
return this.F & bit ? 1 : 0
},
set(value) {
this.F = value
? this.F | bit
: this.F & ~bit
},
enumerable: true
})
})
return registers
}
CpuFlags = ({
zero: 1 << 7,
subtraction: 1 << 6,
halfCarry: 1 << 5,
carry: 1 << 4
})
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@import url('https://fonts.googleapis.com/css2?family=Press+Start+2P&display=swap');
</style>`
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