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| 1 | +#pragma once |
| 2 | +#include "stdafx.h" |
| 3 | +#include "BaseMapper.h" |
| 4 | + |
| 5 | +class Mapper272 : public BaseMapper |
| 6 | +{ |
| 7 | +private: |
| 8 | + uint8_t _chrBanks[8]; |
| 9 | + uint8_t _irqCounter; |
| 10 | + bool _irqEnabled; |
| 11 | + uint16_t _lastPpuAddr; |
| 12 | + |
| 13 | +protected: |
| 14 | + virtual uint16_t GetPRGPageSize() override { return 0x2000; } |
| 15 | + virtual uint16_t GetCHRPageSize() override { return 0x0400; } |
| 16 | + |
| 17 | + void InitMapper() override |
| 18 | + { |
| 19 | + memset(_chrBanks, 0, sizeof(_chrBanks)); |
| 20 | + |
| 21 | + _irqEnabled = false; |
| 22 | + _irqCounter = 0; |
| 23 | + |
| 24 | + SelectPRGPage(2, -2); |
| 25 | + SelectPRGPage(3, -1); |
| 26 | + } |
| 27 | + |
| 28 | + void StreamState(bool saving) override |
| 29 | + { |
| 30 | + BaseMapper::StreamState(saving); |
| 31 | + ArrayInfo<uint8_t> chrBanks = { _chrBanks, 8 }; |
| 32 | + Stream(_irqEnabled, _irqCounter, chrBanks); |
| 33 | + } |
| 34 | + |
| 35 | + void WriteRegister(uint16_t addr, uint8_t value) override |
| 36 | + { |
| 37 | + if((addr >= 0xB000) && (addr <= 0xE003)) { |
| 38 | + uint8_t index = ((((addr >> 12) & 0x07) - 3) << 1) + ((addr >> 1) & 0x01); |
| 39 | + bool lowBits = (addr & 0x01) == 0x00; |
| 40 | + if (lowBits) { |
| 41 | + _chrBanks[index] = (_chrBanks[index] & 0xF0) | (value & 0x0F); |
| 42 | + } else { |
| 43 | + _chrBanks[index] = (_chrBanks[index] & 0x0F) | (value << 4); |
| 44 | + } |
| 45 | + SelectCHRPage(index, _chrBanks[index]); |
| 46 | + } else { |
| 47 | + switch(addr & 0xF000) { |
| 48 | + case 0x8000: |
| 49 | + SelectPRGPage(0, value); |
| 50 | + break; |
| 51 | + |
| 52 | + case 0xA000: |
| 53 | + SelectPRGPage(1, value); |
| 54 | + break; |
| 55 | + |
| 56 | + case 0x9000: |
| 57 | + switch(value & 0x01) { |
| 58 | + case 0: SetMirroringType(MirroringType::Vertical); break; |
| 59 | + case 1: SetMirroringType(MirroringType::Horizontal); break; |
| 60 | + } |
| 61 | + break; |
| 62 | + } |
| 63 | + } |
| 64 | + |
| 65 | + switch(addr & 0xC00C) { |
| 66 | + case 0x8004: |
| 67 | + switch(value & 0x03) { |
| 68 | + case 2: SetMirroringType(MirroringType::ScreenAOnly); break; |
| 69 | + case 3: SetMirroringType(MirroringType::ScreenBOnly); break; |
| 70 | + } |
| 71 | + break; |
| 72 | + |
| 73 | + case 0x800C: |
| 74 | + _console->GetCpu()->SetIrqSource(IRQSource::External); |
| 75 | + break; |
| 76 | + |
| 77 | + case 0xC004: |
| 78 | + _console->GetCpu()->ClearIrqSource(IRQSource::External); |
| 79 | + break; |
| 80 | + |
| 81 | + case 0xC008: |
| 82 | + _irqEnabled = true; |
| 83 | + break; |
| 84 | + |
| 85 | + case 0xC00C: |
| 86 | + _irqEnabled = false; |
| 87 | + _irqCounter = 0; |
| 88 | + _console->GetCpu()->ClearIrqSource(IRQSource::External); |
| 89 | + break; |
| 90 | + } |
| 91 | + } |
| 92 | + |
| 93 | + void NotifyVRAMAddressChange(uint16_t addr) override |
| 94 | + { |
| 95 | + if ((_lastPpuAddr & 0x2000) && !(addr & 0x2000)) { |
| 96 | + if(_irqEnabled) { |
| 97 | + _irqCounter++; |
| 98 | + if(_irqCounter == 84) { |
| 99 | + _irqCounter = 0; |
| 100 | + _console->GetCpu()->SetIrqSource(IRQSource::External); |
| 101 | + } |
| 102 | + } |
| 103 | + } |
| 104 | + |
| 105 | + _lastPpuAddr = addr; |
| 106 | + } |
| 107 | +}; |
| 108 | + |
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