void Utility::modifySystemState(system_state_t systemState) {
  fileBrowser->close();  //avoid edge case oddities (eg movie playback window still open from previous game)
  state.resetHistory();  //do not allow rewinding past a destructive system action
  movie.stop();  //movies cannot continue to record after destructive system actions

  video.clear();
  audio.clear();

  switch(systemState) {
    case LoadCartridge: {
      //must call cartridge.load_cart_...() before calling modifySystemState(LoadCartridge)
      if(SNES::cartridge.loaded() == false) break;
      cartridge.loadCheats();

      application.power = true;
      application.pause = false;
      SNES::system.power();

      //warn if unsupported hardware detected
      string chip;
      if(SNES::cartridge.has_st0018()) chip = "ST-0018";
      if(chip != "") {
        QMessageBox::warning(mainWindow, "Warning", string()
        << "<p><b>Warning:</b><br> The " << chip << " chip was detected, which is not fully emulated yet.<br>"
        << "It is unlikely that this title will work properly.</p>");
      }


      string msgString = string() << "Loaded " << cartridge.name;

      if(cartridge.patchApplied != "")
        msgString << ", and applied " << cartridge.patchApplied << " patch.";
      else
        msgString << ".";

      showMessage(msgString);
      mainWindow->setWindowTitle(string() << cartridge.name << " - " << SNES::Info::Name << " v" << SNES::Info::Version);
      #if defined(DEBUGGER)
      debugger->echo(string() << "Loaded " << cartridge.name << ".<br>");
      #endif
    } break;

    case UnloadCartridge: {
      if(SNES::cartridge.loaded() == false) break;  //no cart to unload?
      cartridge.saveCheats();

      SNES::system.unload();     //flush all memory to memory::* devices
      cartridge.saveMemory();    //save memory to disk
      SNES::cartridge.unload();  //deallocate memory
      music.unload();            //disable music display

      application.power = false;
      application.pause = true;

      showMessage(string() << "Unloaded " << cartridge.name << ".");
      mainWindow->setWindowTitle(string() << SNES::Info::Name << " v" << SNES::Info::Version);
    } break;

    case PowerOn: {
      if(SNES::cartridge.loaded() == false || application.power == true) break;

      application.power = true;
      application.pause = false;
      SNES::system.power();

      showMessage("Power on.");
    } break;

    case PowerOff: {
      if(SNES::cartridge.loaded() == false || application.power == false) break;

      application.power = false;
      application.pause = true;

      showMessage("Power off.");
    } break;

    case PowerCycle: {
      if(SNES::cartridge.loaded() == false) break;

      application.power = true;
      application.pause = false;
      SNES::system.power();

      showMessage("System power was cycled.");
    } break;

    case ReloadCartridge: {
      if(application.currentRom != "") {
        application.reloadCartridge();
        showMessage(string() << "Reloaded " << cartridge.name << ".");
	  }
    } break;

    case Reset: {
      if(SNES::cartridge.loaded() == false || application.power == false) break;

      application.pause = false;
      SNES::system.reset();

      showMessage("System was reset.");
    } break;
  }

  if(!application.power) unacquireMouse();

  // don't let widget updates temporarily draw a parent widget over an external rendering context
  // (only applies when the system is powered on)
  mainWindow->canvas->setUpdatesEnabled(!application.power || video.cap("QWidget"));

  mainWindow->system_saveMemoryPack->setVisible(SNES::cartridge.loaded() 
    && SNES::cartridge.has_bsx_slot() && (SNES::memory::bsxpack.size() > 0));

  mainWindow->syncUi();
  #if defined(DEBUGGER)
  debugger->modifySystemState(systemState);
  debugger->synchronize();
  #endif
  cheatEditorWindow->synchronize();
  cheatFinderWindow->synchronize();
  manifestViewerWindow->synchronize();
  stateManagerWindow->reload();
}