CaltronMapper.java

package com.grapeshot.halfnes.mappers;

import com.grapeshot.halfnes.*;

public class CaltronMapper extends Mapper {

    int reg = 0;

    @Override
    public void loadrom() throws BadMapperException {
        //needs to be in every mapper. Fill with initial cfg
        super.loadrom();
        for (int i = 0; i < 32; ++i) {
            prg_map[i] = (1024 * i) & (prgsize - 1);
        }
        for (int i = 0; i < 8; ++i) {
            chr_map[i] = (1024 * i) & (chrsize - 1);
        }
    }

    @Override
    public final void cartWrite(final int addr, final int data) {
        if (addr >= 0x6000 && addr <= 0x67FF) {
            reg = addr & 0xFF;

            //remap PRG bank
            for (int i = 0; i < 32; ++i) {
                prg_map[i] = (1024 * (i + 32 * (addr & 7))) & (prgsize - 1);
            }

            setmirroring(((addr & (utils.BIT5)) != 0) ? MirrorType.H_MIRROR : MirrorType.V_MIRROR);
        } else if (addr >= 0x8000 && addr <= 0xFFFF && (reg & 4) != 0) {
            //remap CHR bank
            for (int i = 0; i < 8; ++i) {
                chr_map[i] = (1024 * (i + 8 * ((reg >> 1 & 0xC) | (data & 3)))) & (chrsize - 1);
            }
        }
    }
}