330 lines
7.2 KiB
C++
330 lines
7.2 KiB
C++
#include "nes_mapper.h"
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Mapper1Res *MAP1;
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// Mapper 1
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void MAP1_Reset()
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{
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MAP1->write_count = 0;
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MAP1->bits = 0x00;
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MAP1->regs[0] = 0x0C; // reflects initial ROM state
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MAP1->regs[1] = 0x00;
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MAP1->regs[2] = 0x00;
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MAP1->regs[3] = 0x00;
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{
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uint32 size_in_K = num_8k_ROM_banks * 8;
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if(size_in_K == 1024)
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{
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MAP1->MMC1_Size = MMC1_1024K;
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}
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else if(size_in_K == 512)
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{
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MAP1->MMC1_Size = MMC1_512K;
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}
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else
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{
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MAP1->MMC1_Size = MMC1_SMALL;
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}
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}
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MAP1->MMC1_256K_base = 0; // use first 256K
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MAP1->MMC1_swap = 0;
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if(MAP1->MMC1_Size == MMC1_SMALL)
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{
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// set two high pages to last two banks
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MAP1->MMC1_HI1 = num_8k_ROM_banks-2;
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MAP1->MMC1_HI2 = num_8k_ROM_banks-1;
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}
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else
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{
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// set two high pages to last two banks of current 256K region
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MAP1->MMC1_HI1 = (256/8)-2;
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MAP1->MMC1_HI2 = (256/8)-1;
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}
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// set CPU bank pointers
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MAP1->MMC1_bank1 = 0;
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MAP1->MMC1_bank2 = 1;
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MAP1->MMC1_bank3 = MAP1->MMC1_HI1;
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MAP1->MMC1_bank4 = MAP1->MMC1_HI2;
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}
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void MAP1_MMC1_set_CPU_banks()
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{
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set_CPU_banks((MAP1->MMC1_256K_base << 5) + (MAP1->MMC1_bank1 & ((256/8)-1)),
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(MAP1->MMC1_256K_base << 5) + (MAP1->MMC1_bank2 & ((256/8)-1)),
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(MAP1->MMC1_256K_base << 5) + (MAP1->MMC1_bank3 & ((256/8)-1)),
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(MAP1->MMC1_256K_base << 5) + (MAP1->MMC1_bank4 & ((256/8)-1)));
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}
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void MAP1_MemoryWrite(uint16 addr, uint8 data)
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{
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uint32 reg_num;
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// if write is to a different reg, reset
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if((addr & 0x6000) != (MAP1->last_write_addr & 0x6000))
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{
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MAP1->write_count = 0;
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MAP1->bits = 0x00;
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}
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MAP1->last_write_addr = addr;
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// if bit 7 set, reset and return
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if(data & 0x80)
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{
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MAP1->write_count = 0;
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MAP1->bits = 0x00;
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return;
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}
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if(data & 0x01) MAP1->bits |= (1 << MAP1->write_count);
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MAP1->write_count++;
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if(MAP1->write_count < 5) return;
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reg_num = (addr & 0x7FFF) >> 13;
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MAP1->regs[reg_num] = MAP1->bits;
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MAP1->write_count = 0;
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MAP1->bits = 0x00;
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// LOG("MAP1 REG" << reg_num << ": " << HEX(MAP1->regs[reg_num],2) << endl);
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switch(reg_num)
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{
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case 0:
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{
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// LOG("REG0: " << HEX(reg[0],2) << endl);
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// set mirroring
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if(MAP1->regs[0] & 0x02)
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{
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if(MAP1->regs[0] & 0x01)
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{
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set_mirroring(0,0,1,1);//ˮƽ<CBAE><C6BD><EFBFBD><EFBFBD>InfoNES_Mirroring( 0 ); //0011
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//set_mirroring(NES_PPU::MIRROR_HORIZ);
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}
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else
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{
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set_mirroring(0,1,0,1);//<2F><>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD>InfoNES_Mirroring( 1 ); //0101
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//set_mirroring(NES_PPU::MIRROR_VERT);
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}
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}
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else
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{
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// one-screen mirroring
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if(MAP1->regs[0] & 0x01)
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{
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set_mirroring(1,1,1,1);
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}
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else
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{
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set_mirroring(0,0,0,0);
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}
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}
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}
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break;
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case 1:
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{
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uint8 bank_num = MAP1->regs[1];
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// LOG("REG1: " << HEX(reg[1],2) << endl);
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if(MAP1->MMC1_Size == MMC1_1024K)
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{
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if(MAP1->regs[0] & 0x10)
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{
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if(MAP1->MMC1_swap)
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{
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MAP1->MMC1_256K_base = (MAP1->regs[1] & 0x10) >> 4;
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if(MAP1->regs[0] & 0x08)
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{
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MAP1->MMC1_256K_base |= ((MAP1->regs[2] & 0x10) >> 3);
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}
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MAP1_MMC1_set_CPU_banks();
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MAP1->MMC1_swap = 0;
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}
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else
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{
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MAP1->MMC1_swap = 1;
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}
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}
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else
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{
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// use 1st or 4th 256K banks
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MAP1->MMC1_256K_base = (MAP1->regs[1] & 0x10) ? 3 : 0;
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MAP1_MMC1_set_CPU_banks();
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}
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}
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else if((MAP1->MMC1_Size == MMC1_512K) && (!num_1k_VROM_banks))
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{
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MAP1->MMC1_256K_base = (MAP1->regs[1] & 0x10) >> 4;
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MAP1_MMC1_set_CPU_banks();
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}
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else if(num_1k_VROM_banks)
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{
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// set VROM bank at $0000
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if(MAP1->regs[0] & 0x10)
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{
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// swap 4K
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bank_num <<= 2;
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set_PPU_bank0(bank_num+0);
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set_PPU_bank1(bank_num+1);
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set_PPU_bank2(bank_num+2);
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set_PPU_bank3(bank_num+3);
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}
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else
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{
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// swap 8K
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bank_num <<= 2;
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set_PPU_banks(bank_num+0,bank_num+1,bank_num+2,bank_num+3,
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bank_num+4,bank_num+5,bank_num+6,bank_num+7);
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}
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}
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else
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{
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if(MAP1->regs[0] & 0x10)
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{
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bank_num <<= 2;
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set_VRAM_bank(0, bank_num+0);
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set_VRAM_bank(1, bank_num+1);
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set_VRAM_bank(2, bank_num+2);
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set_VRAM_bank(3, bank_num+3);
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}
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}
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}
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break;
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case 2:
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{
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uint8 bank_num = MAP1->regs[2];
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// LOG("REG2: " << HEX(reg[2],2) << endl);
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if((MAP1->MMC1_Size == MMC1_1024K) && (MAP1->regs[0] & 0x08))
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{
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if(MAP1->MMC1_swap)
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{
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MAP1->MMC1_256K_base = (MAP1->regs[1] & 0x10) >> 4;
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MAP1->MMC1_256K_base |= ((MAP1->regs[2] & 0x10) >> 3);
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MAP1_MMC1_set_CPU_banks();
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MAP1->MMC1_swap = 0;
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}
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else
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{
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MAP1->MMC1_swap = 1;
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}
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}
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if(!num_1k_VROM_banks)
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{
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if(MAP1->regs[0] & 0x10)
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{
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bank_num <<= 2;
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set_VRAM_bank(4, bank_num+0);
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set_VRAM_bank(5, bank_num+1);
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set_VRAM_bank(6, bank_num+2);
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set_VRAM_bank(7, bank_num+3);
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break;
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}
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}
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// set 4K VROM bank at $1000
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if(MAP1->regs[0] & 0x10)
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{
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// swap 4K
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bank_num <<= 2;
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set_PPU_bank4(bank_num+0);
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set_PPU_bank5(bank_num+1);
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set_PPU_bank6(bank_num+2);
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set_PPU_bank7(bank_num+3);
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}
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}
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break;
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case 3:
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{
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uint8 bank_num = MAP1->regs[3];
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// LOG("REG3: " << HEX(reg[3],2) << endl);
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// set ROM bank
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if(MAP1->regs[0] & 0x08)
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{
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// 16K of ROM
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bank_num <<= 1;
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if(MAP1->regs[0] & 0x04)
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{
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// 16K of ROM at $8000
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MAP1->MMC1_bank1 = bank_num;
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MAP1->MMC1_bank2 = bank_num+1;
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MAP1->MMC1_bank3 = MAP1->MMC1_HI1;
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MAP1->MMC1_bank4 = MAP1->MMC1_HI2;
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}
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else
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{
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// 16K of ROM at $C000
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if(MAP1->MMC1_Size == MMC1_SMALL)
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{
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MAP1->MMC1_bank1 = 0;
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MAP1->MMC1_bank2 = 1;
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MAP1->MMC1_bank3 = bank_num;
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MAP1->MMC1_bank4 = bank_num+1;
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}
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}
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}
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else
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{
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// 32K of ROM at $8000
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bank_num <<= 1; // thanx rinao
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MAP1->MMC1_bank1 = bank_num;
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MAP1->MMC1_bank2 = bank_num+1;
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if(MAP1->MMC1_Size == MMC1_SMALL)
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{
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MAP1->MMC1_bank3 = bank_num+2;
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MAP1->MMC1_bank4 = bank_num+3;
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}
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}
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MAP1_MMC1_set_CPU_banks();
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}
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break;
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}
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}
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void MAP1_Init()
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{
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NES_Mapper->Reset=MAP1_Reset;
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NES_Mapper->Write=MAP1_MemoryWrite;
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}
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