NES-emulator/mapper000.cpp at master · LucaDavidian/NES-emulator · GitHub

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#include "mapper000.hpp"

/**** mapper 000 ****/

uint32_t Mapper000::MapReadPRG(uint16_t address, bool &fromRAM)
{
    uint32_t mappedAddress = 0x00000000;

    if (address >= 0x6000 && address <= 0x7FFF)
    {
        mappedAddress = address & 0x1FFF;
        fromRAM = true;
    }
    else if (address >= 0x8000 && address <= 0xFFFF)
    {
        if (numBanksPRG == 1)                                           // mapped PRG address == first 14 bits if 16 KiB (0x8000 - 0xBFFF mirrored 0xC000 - 0xFFFF)
            mappedAddress = address & 0x3FFF;
        else if (numBanksPRG == 2)                                      // mapped PRG address == first 15 bits if 32 KiB (0x8000 - 0xFFFF)
            mappedAddress = address & 0x7FFF;
    }

    return mappedAddress;
}

uint32_t Mapper000::MapWritePRG(uint16_t address, uint8_t data, bool &toRAM)
{
    uint32_t mappedAddress = 0x00000000;

    if (address >= 0x6000 && address <= 0x7FFF)
    {
        mappedAddress = address & 0x1FFF;
        toRAM = true;
    }
    else if (address >= 0x8000 && address <= 0xFFFF)
    {
        if (numBanksPRG == 1)                                           // mapped PRG address == first 14 bits if 16 KiB (0x8000 - 0xBFFF mirrored 0xC000 - 0xFFFF)
            mappedAddress = address & 0x3FFF;
        else if (numBanksPRG == 2)                                      // mapped PRG address == first 15 bits if 32 KiB (0x8000 - 0xFFFF)
            mappedAddress = address & 0x7FFF;
    }

    return mappedAddress;
}

uint32_t Mapper000::MapReadCHR(uint16_t address)
{
    return address;
}

uint32_t Mapper000::MapWriteCHR(uint16_t address)
{
    return address;
}