content: 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);
              }
          }
      }
  }
  