mattelchess: add save switch (nw)

src/devices/video/hlcd0515.cpp

@@ -2,12 +2,16 @@
 // copyright-holders:hap
 /*
 
-  Hughes HLCD 0515 family LCD Driver
+Hughes HLCD 0515 family LCD Driver
 
-  0515: 25 columns(also size of buffer/ram)
+0515: 25 columns(also size of buffer/ram)
-  0569: 24 columns, display blank has no effect(instead it's external with VDRIVE?)
+0569: 24 columns, display blank has no effect(instead it's external with VDRIVE?)
-  0530: specifications unknown, pinout seems similar to 0569
+0530: specifications unknown, pinout seems similar to 0569
-  0601: specifications unknown, pinout seems similar to 0569
+0601: specifications unknown, pinout seems similar to 0569
+
+TODO:
+- Does DATA OUT pin function the same on each chip? The 0515 datasheet says that
+  the 25th column is output first, but on 0569(no datasheet available) it's reversed.
 
 */
 
@@ -129,7 +133,7 @@ void hlcd0515_device::set_control()
 	if (m_control & 1)
 	{
 		m_buffer = m_ram[m_rowsel];
-		clock_data(-1);
+		clock_data();
 	}
 	else
 		m_buffer = 0;
@@ -149,8 +153,7 @@ void hlcd0515_device::clock_data(int col)
 		m_dataout = m_buffer & 1;
 		m_write_data(m_dataout);
 
-		if (col < m_colmax)
+		m_buffer >>= 1;
-			m_buffer >>= 1;
 	}
 	else
 	{

src/devices/video/hlcd0515.h

@@ -63,7 +63,7 @@ protected:
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	virtual void set_control();
-	void clock_data(int col);
+	void clock_data(int col = 0);
 
 	const u8 m_colmax;    // number of column pins
 

src/mame/drivers/mattelchess.cpp

@@ -11,7 +11,6 @@ Hardware notes:
 - custom LCD screen with chess squares background
 
 TODO:
-- add SAVE switch
 - internal artwork
 
 ******************************************************************************/
@@ -37,19 +36,24 @@ public:
 
 	void mchess(machine_config &config);
 
+	DECLARE_INPUT_CHANGED_MEMBER(reset_switch) { update_reset(newval); }
+
 protected:
 	virtual void machine_start() override;
+	virtual void machine_reset() override;
 
 private:
 	// devices/pointers
 	required_device<mcs48_cpu_device> m_maincpu;
 	required_device_array<hlcd0569_device, 2> m_lcd;
-	required_ioport_array<3> m_inputs;
+	required_ioport_array<4> m_inputs;
 	output_finder<2, 8, 22> m_out_x;
 
 	u8 m_inp_mux;
 	u8 m_lcd_control;
 
+	void update_reset(ioport_value state);
+
 	// I/O handlers
 	template<int Sel> DECLARE_WRITE32_MEMBER(lcd_output_w);
 	DECLARE_WRITE8_MEMBER(input_w);
@@ -72,6 +76,19 @@ void mchess_state::machine_start()
 	save_item(NAME(m_lcd_control));
 }
 
+void mchess_state::machine_reset()
+{
+	update_reset(m_inputs[3]->read());
+}
+
+void mchess_state::update_reset(ioport_value state)
+{
+	// assume that SAVE switch powers off the CPU
+	// (at reboot, the game will read the chessboard positions from LCD RAM)
+	m_maincpu->set_input_line(INPUT_LINE_RESET, state ? ASSERT_LINE : CLEAR_LINE);
+}
+
+
 
 /******************************************************************************
     Devices, I/O
@@ -80,10 +97,12 @@ void mchess_state::machine_start()
 template<int Sel>
 WRITE32_MEMBER(mchess_state::lcd_output_w)
 {
+	int enabled = ~m_inputs[3]->read() & m_lcd_control & 1;
+
 	// output to x.y.z where x = chip, y = row, z = col
 	// up to 22 columns used
 	for (int i = 0; i < 22; i++)
-		m_out_x[Sel][offset][i] = BIT(data, i);
+		m_out_x[Sel][offset][i] = BIT(data, i) & enabled;
 }
 
 WRITE8_MEMBER(mchess_state::input_w)
@@ -161,6 +180,9 @@ static INPUT_PORTS_START( mchess )
 	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_BACKSPACE) PORT_CODE(KEYCODE_DEL) PORT_NAME("Clear")
 	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_C) PORT_NAME("Color")
 	PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_CODE(KEYCODE_B) PORT_NAME("Take Back")
+
+	PORT_START("IN.3")
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_CODE(KEYCODE_F1) PORT_TOGGLE PORT_CHANGED_MEMBER(DEVICE_SELF, mchess_state, reset_switch, nullptr) PORT_NAME("Save Switch")
 INPUT_PORTS_END