content: /*
   * HalfNES by Andrew Hoffman
   * Licensed under the GNU GPL Version 3. See LICENSE file
   */
  package com.grapeshot.halfnes.mappers;
  
  import com.grapeshot.halfnes.utils;
  
  /**
   *
   * @author Andrew
   */
  public class Mapper87 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 final void cartWrite(final int addr, final int data) {
          if (addr >= 0x6000 && addr < 0x8000) {
              //remap CHR bank
              int bit0 = (data >> 1) & 1;
              int bit1 = data & 1;
              for (int i = 0; i < 8; ++i) {
                  chr_map[i] = (1024 * (i + 8 * ((bit1 << 1) + bit0))) & (chrsize - 1);
              }
          } else {
              super.cartWrite(addr, data);
          }
      }
  }
  