62 lines
No EOL
1.5 KiB
C++
62 lines
No EOL
1.5 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "GbCart.h"
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#include "GbMemoryManager.h"
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#include "../Utilities/Serializer.h"
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class GbMbc1 : public GbCart
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{
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private:
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bool _ramEnabled = false;
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uint8_t _prgBank = 1;
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uint8_t _ramBank = 0;
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bool _mode = false;
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public:
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void InitCart() override
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{
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_memoryManager->MapRegisters(0x0000, 0x7FFF, RegisterAccess::Write);
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}
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void RefreshMappings() override
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{
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constexpr int prgBankSize = 0x4000;
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constexpr int ramBankSize = 0x2000;
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Map(0x0000, 0x3FFF, GbMemoryType::PrgRom, (_mode ? (_ramBank << 5) : 0) * prgBankSize, true);
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uint8_t prgBank = _prgBank | (_ramBank << 5);
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Map(0x4000, 0x7FFF, GbMemoryType::PrgRom, prgBank*prgBankSize, true);
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if(_ramEnabled) {
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uint8_t ramBank = _mode ? _ramBank : 0;
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Map(0xA000, 0xBFFF, GbMemoryType::CartRam, ramBank*ramBankSize, false);
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_memoryManager->MapRegisters(0xA000, 0xBFFF, RegisterAccess::None);
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} else {
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Unmap(0xA000, 0xBFFF);
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_memoryManager->MapRegisters(0xA000, 0xBFFF, RegisterAccess::Read);
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}
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}
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uint8_t ReadRegister(uint16_t addr) override
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{
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//Disabled RAM returns 0xFF on reads
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return 0xFF;
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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 & 0x6000) {
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case 0x0000: _ramEnabled = ((value & 0x0F) == 0x0A); break;
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case 0x2000: _prgBank = std::max(1, value & 0x1F); break;
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case 0x4000: _ramBank = value & 0x03; break;
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case 0x6000: _mode = (value & 0x01) != 0; break;
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}
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RefreshMappings();
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}
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void Serialize(Serializer& s) override
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{
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s.Stream(_ramEnabled, _prgBank, _ramBank, _mode);
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}
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}; |