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64 lines
1.6 KiB
C++
64 lines
1.6 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "BaseMapper.h"
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#include "CPU.h"
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#include "A12Watcher.h"
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class Mapper222 : public BaseMapper
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{
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private:
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uint16_t _irqCounter;
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A12Watcher _a12Watcher;
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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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_irqCounter = 0;
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SelectPrgPage2x(1, -2);
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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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SnapshotInfo a12Watcher{ &_a12Watcher };
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Stream(_irqCounter, a12Watcher);
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}
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virtual void NotifyVRAMAddressChange(uint16_t addr) override
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{
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if(_a12Watcher.UpdateVramAddress(addr) == A12StateChange::Rise) {
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if(_irqCounter) {
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_irqCounter++;
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if(_irqCounter >= 240) {
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CPU::SetIRQSource(IRQSource::External);
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_irqCounter = 0;
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}
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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 & 0xF003) {
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case 0x8000: SelectPRGPage(0, value); break;
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case 0x9000: SetMirroringType(value & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical); break;
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case 0xA000: SelectPRGPage(1, value); break;
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case 0xB000: SelectCHRPage(0, value); break;
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case 0xB002: SelectCHRPage(1, value); break;
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case 0xC000: SelectCHRPage(2, value); break;
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case 0xC002: SelectCHRPage(3, value); break;
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case 0xD000: SelectCHRPage(4, value); break;
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case 0xD002: SelectCHRPage(5, value); break;
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case 0xE000: SelectCHRPage(6, value); break;
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case 0xE002: SelectCHRPage(7, value); break;
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case 0xF000:
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_irqCounter = value;
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CPU::ClearIRQSource(IRQSource::External);
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break;
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}
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}
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}; |