content: package com.grapeshot.halfnes.mappers;
  
  import com.grapeshot.halfnes.*;
  
  public class Mapper61 extends Mapper {
  
      @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 void reset() {
          cartWrite(0x8000, cartRead(0x8000));
      }
  
      @Override
      public final void cartWrite(final int addr, final int data) {
          if (addr < 0x8000 || addr > 0xffff) {
              super.cartWrite(addr, data);
              return;
          }
  
          switch (addr & 0x30) {
              case 0x00:
              case 0x30:
                  for (int i = 0; i < 32; ++i) {
                      prg_map[i] = (1024 * (i + 32 * (addr & 0xF))) & (prgsize - 1);
                  }
                  break;
              case 0x10:
              case 0x20:
                  int prgselect = (addr << 1 & 0x1E) | (addr >> 4 & 2);
                  for (int i = 0; i < 16; ++i) {
                      prg_map[i] = (1024 * (i + 32 * prgselect)) & (prgsize - 1);
                  }
                  for (int i = 0; i < 16; ++i) {
                      prg_map[i + 16] = (1024 * (i + 32 * prgselect)) & (prgsize - 1);
                  }
          }
  
          setmirroring(((addr & (utils.BIT7)) != 0) ? MirrorType.H_MIRROR : MirrorType.V_MIRROR);
      }
  }