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68 lines
1.6 KiB
C++
68 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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class Bmc235 : public BaseMapper
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{
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private:
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bool _openBus = false;
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protected:
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virtual uint16_t GetPRGPageSize() override { return 0x4000; }
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virtual uint16_t GetCHRPageSize() override { return 0x2000; }
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void InitMapper() override
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{
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SelectPrgPage2x(0, 0);
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SelectCHRPage(0, 0);
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}
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void Reset(bool softReset) override
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{
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SelectPrgPage2x(0, 0);
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_openBus = false;
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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(_openBus);
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if(!saving && _openBus) {
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RemoveCpuMemoryMapping(0x8000, 0xFFFF);
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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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SetMirroringType((addr & 0x0400) ? MirroringType::ScreenAOnly : (addr & 0x2000) ? MirroringType::Horizontal : MirroringType::Vertical);
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const uint8_t config[4][4][2] = {
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{ { 0x00, 0 }, { 0x00, 1 }, { 0x00, 1 }, { 0x00, 1 } },
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{ { 0x00, 0 }, { 0x00, 1 }, { 0x20, 0 }, { 0x00, 1 } },
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{ { 0x00, 0 }, { 0x00, 1 }, { 0x20, 0 }, { 0x40, 0 } },
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{ { 0x00, 0 }, { 0x20, 0 }, { 0x40, 0 }, { 0x60, 0 } }
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};
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uint8_t mode;
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switch(GetPRGPageCount()) {
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case 64: mode = 0; break;
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case 128: mode = 1; break;
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case 256: mode = 2; break;
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default: mode = 3; break;
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};
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uint8_t bank = config[mode][addr >> 8 & 0x03][0] | (addr & 0x1F);
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_openBus = false;
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if(config[mode][addr >> 8 & 0x03][1]) {
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//Open bus
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_openBus = true;
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RemoveCpuMemoryMapping(0x8000, 0xFFFF);
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} else if(addr & 0x800) {
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bank = (bank << 1) | (addr >> 12 & 0x01);
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SelectPRGPage(0, bank);
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SelectPRGPage(1, bank);
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} else {
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SelectPrgPage2x(0, bank << 1);
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}
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}
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}; |