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https://github.com/libretro/Mesen.git
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69 lines
1.5 KiB
C++
69 lines
1.5 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "BaseMapper.h"
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class Mapper106 : public BaseMapper
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{
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private:
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uint16_t _irqCounter;
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bool _irqEnabled;
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protected:
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virtual uint16_t GetPRGPageSize() override { return 0x2000; }
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virtual uint16_t GetCHRPageSize() override { return 0x400; }
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void InitMapper() override
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{
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_irqEnabled = false;
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_irqCounter = 0;
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SelectPRGPage(0, -1);
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SelectPRGPage(1, -1);
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SelectPRGPage(2, -1);
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SelectPRGPage(3, -1);
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}
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void StreamState(bool saving) override
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{
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BaseMapper::StreamState(saving);
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Stream(_irqCounter, _irqEnabled);
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}
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void ProcessCpuClock() override
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{
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if(_irqEnabled) {
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_irqCounter++;
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if(_irqCounter == 0) {
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CPU::SetIRQSource(IRQSource::External);
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_irqEnabled = false;
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}
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}
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}
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void WriteRegister(uint16_t addr, uint8_t value) override
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{
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switch(addr & 0x0F) {
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case 0: case 2: SelectCHRPage(addr & 0x0F, value & 0xFE); break;
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case 1: case 3: SelectCHRPage(addr & 0x0F, value | 0x01); break;
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case 4: case 5: case 6: case 7: SelectCHRPage(addr & 0x0F, value); break;
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case 8: case 0x0B: SelectPRGPage((addr & 0x0F) - 8, (value & 0x0F) | 0x10); break;
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case 9: case 0x0A: SelectPRGPage((addr & 0x0F) - 8, value & 0x1F); break;
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case 0x0D:
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_irqEnabled = false;
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_irqCounter = 0;
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CPU::ClearIRQSource(IRQSource::External);
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break;
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case 0x0E:
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_irqCounter = (_irqCounter & 0xFF00) | value;
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break;
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case 0x0F:
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_irqCounter = (_irqCounter & 0xFF) | (value << 8);
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_irqEnabled = true;
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break;
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}
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}
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}; |