text: // license:BSD-3-Clause
  // copyright-holders:hap
  // thanks-to:bataais
  /******************************************************************************
  
  Fidelity Eldorado Chess Challenger (model 6119)
  
  Hardware notes:
  - PCB label CXG262-600-001, CXG262-600-101
  - TMP80C49AP6-6744 MCU, 2KB internal ROM, 6MHz XTAL
  - buzzer, 16 leds, 8*8 chessboard buttons
  
  The chess engine is by Ron Nelson. The hardware was made by CXG for Fidelity,
  as seen on the PCB and also confirmed by Ron Nelson.
  
  ******************************************************************************/
  
  #include "emu.h"
  
  #include "cpu/mcs48/mcs48.h"
  #include "machine/sensorboard.h"
  #include "sound/dac.h"
  #include "video/pwm.h"
  
  #include "speaker.h"
  
  // internal artwork
  #include "fidel_eldorado.lh" // clickable
  
  
  namespace {
  
  class eldorado_state : public driver_device
  {
  public:
  	eldorado_state(const machine_config &mconfig, device_type type, const char *tag) :
  		driver_device(mconfig, type, tag),
  		m_maincpu(*this, "maincpu"),
  		m_display(*this, "display"),
  		m_board(*this, "board"),
  		m_dac(*this, "dac"),
  		m_inputs(*this, "IN.0")
  	{ }
  
  	// machine configs
  	void eldorado(machine_config &config);
  
  protected:
  	virtual void machine_start() override;
  
  private:
  	// devices/pointers
  	required_device<mcs48_cpu_device> m_maincpu;
  	required_device<pwm_display_device> m_display;
  	required_device<sensorboard_device> m_board;
  	required_device<dac_bit_interface> m_dac;
  	required_ioport m_inputs;
  
  	// I/O handlers
  	void update_display();
  	void mux_w(u8 data);
  	u8 mux_r();
  	void control_w(u8 data);
  	DECLARE_READ_LINE_MEMBER(t0_r);
  	u8 input_r();
  
  	bool m_kp_select = false;
  	u16 m_inp_mux = 0;
  	u8 m_led_select = 0;
  };
  
  void eldorado_state::machine_start()
  {
  	// register for savestates
  	save_item(NAME(m_kp_select));
  	save_item(NAME(m_inp_mux));
  	save_item(NAME(m_led_select));
  }
  
  
  
  /******************************************************************************
      I/O
  ******************************************************************************/
  
  void eldorado_state::update_display()
  {
  	m_display->matrix(m_led_select, m_inp_mux);
  }
  
  void eldorado_state::mux_w(u8 data)
  {
  	// D0-D7: input mux, led data
  	m_inp_mux = ~data;
  	update_display();
  }
  
  u8 eldorado_state::mux_r()
  {
  	return ~m_inp_mux;
  }
  
  void eldorado_state::control_w(u8 data)
  {
  	// P24: speaker out
  	m_dac->write(BIT(~data, 4));
  
  	// P25,P26: led select
  	m_led_select = ~data >> 5 & 3;
  	update_display();
  
  	// P27: keypad select
  	m_kp_select = !bool(data & 0x80);
  }
  
  READ_LINE_MEMBER(eldorado_state::t0_r)
  {
  	// T0: P27
  	return m_kp_select ? 0 : 1;
  }
  
  u8 eldorado_state::input_r()
  {
  	u8 data = 0;
  
  	// P10-P17: multiplexed inputs
  	// read chessboard buttons
  	for (int i = 0; i < 8; i++)
  		if (BIT(m_inp_mux, i))
  			data |= m_board->read_file(i);
  
  	// read sidepanel keypad
  	if (m_kp_select)
  		data |= m_inputs->read();
  
  	return ~data;
  }
  
  
  
  /******************************************************************************
      Input Ports
  ******************************************************************************/
  
  static INPUT_PORTS_START( eldorado )
  	PORT_START("IN.0")
  	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_1) PORT_CODE(KEYCODE_1_PAD) PORT_NAME("Reverse / Pawn")
  	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_2) PORT_CODE(KEYCODE_2_PAD) PORT_NAME("Move / Knight")
  	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_3) PORT_CODE(KEYCODE_3_PAD) PORT_NAME("Sound / Bishop")
  	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_4) PORT_CODE(KEYCODE_4_PAD) PORT_NAME("Level / Rook")
  	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_5) PORT_CODE(KEYCODE_5_PAD) PORT_NAME("Verify / Queen")
  	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_6) PORT_CODE(KEYCODE_6_PAD) PORT_NAME("Problem / King")
  	PORT_BIT(0x40, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_DEL) PORT_CODE(KEYCODE_BACKSPACE) PORT_NAME("Clear")
  	PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_N) PORT_NAME("New Game")
  INPUT_PORTS_END
  
  
  
  /******************************************************************************
      Machine Configs
  ******************************************************************************/
  
  void eldorado_state::eldorado(machine_config &config)
  {
  	/* basic machine hardware */
  	I8049(config, m_maincpu, 6_MHz_XTAL);
  	m_maincpu->p1_in_cb().set(FUNC(eldorado_state::input_r));
  	m_maincpu->p2_out_cb().set(FUNC(eldorado_state::control_w));
  	m_maincpu->bus_in_cb().set(FUNC(eldorado_state::mux_r));
  	m_maincpu->bus_out_cb().set(FUNC(eldorado_state::mux_w));
  	m_maincpu->t0_in_cb().set(FUNC(eldorado_state::t0_r));
  
  	SENSORBOARD(config, m_board).set_type(sensorboard_device::BUTTONS);
  	m_board->init_cb().set(m_board, FUNC(sensorboard_device::preset_chess));
  	m_board->set_delay(attotime::from_msec(150));
  
  	/* video hardware */
  	PWM_DISPLAY(config, m_display).set_size(2, 8);
  	config.set_default_layout(layout_fidel_eldorado);
  
  	/* sound hardware */
  	SPEAKER(config, "speaker").front_center();
  	DAC_1BIT(config, m_dac).add_route(ALL_OUTPUTS, "speaker", 0.25);
  }
  
  
  
  /******************************************************************************
      ROM Definitions
  ******************************************************************************/
  
  ROM_START( feldo )
  	ROM_REGION( 0x0800, "maincpu", 0 )
  	ROM_LOAD("100-1027a01", 0x0000, 0x0800, CRC(3b93b6d2) SHA1(353a741624b4c7fd74a0cf601e2e52f9914b58b8) )
  ROM_END
  
  } // anonymous namespace
  
  
  
  /******************************************************************************
      Drivers
  ******************************************************************************/
  
  //    YEAR  NAME    PARENT   COMPAT  MACHINE   INPUT     CLASS           INIT        COMPANY, FULLNAME, FLAGS
  CONS( 1990, feldo,  0,       0,      eldorado, eldorado, eldorado_state, empty_init, "Fidelity Electronics / CXG Systems", "Eldorado Chess Challenger", MACHINE_SUPPORTS_SAVE | MACHINE_CLICKABLE_ARTWORK )
  