Cleaned up serial, matrix keyboard and TI-8x link protocol interfaces:

* Switched to delegate timers
 - Frees implementations from having to call timer method
 - Eliminates risk of ID conflicts with implementations/other interfaces
* Moved save state registration to interface post start
 - Plays nicely with device_missing_dependencies exceptions
 - Frees implementation from having to call save state registration method
 - Improves save state support in devices that neglected to call method

src/devices/bus/apricot/keyboard/hle.cpp

@@ -224,7 +224,6 @@ apricot_keyboard_hle_device::apricot_keyboard_hle_device(const machine_config &m
 
 void apricot_keyboard_hle_device::device_start()
 {
-	device_buffered_serial_interface::register_save_state(machine().save(), this);
 }
 
 //-------------------------------------------------
@@ -348,13 +347,3 @@ void apricot_keyboard_hle_device::out_w(int state)
 {
 	device_buffered_serial_interface::rx_w(state);
 }
-
-//-------------------------------------------------
-//  device_timer - device-specific timer
-//-------------------------------------------------
-
-void apricot_keyboard_hle_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	device_buffered_serial_interface::device_timer(timer, id, param, ptr);
-}

src/devices/bus/apricot/keyboard/hle.h

@@ -49,8 +49,6 @@ protected:
 	virtual void key_make(uint8_t row, uint8_t column) override;
 	virtual void key_break(uint8_t row, uint8_t column) override;
 
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
-
 private:
 	enum {
 		CMD_REQ_TIME_AND_DATE = 0xe1,

src/devices/bus/hp_hil/hlekbd.cpp

@@ -277,16 +277,6 @@ void hle_device_base::device_reset()
 }
 
 
-/*--------------------------------------------------
-    hle_device_base::device_timer
-    handle timed events
---------------------------------------------------*/
-
-void hle_device_base::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-}
-
 void hle_device_base::hil_write(uint16_t data)
 {
 	int frames = 0;

src/devices/bus/hp_hil/hlekbd.h

@@ -26,7 +26,6 @@ protected:
 	// device overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_matrix_keyboard_interface overrides
 	virtual void key_make(uint8_t row, uint8_t column) override;
@@ -36,9 +35,6 @@ protected:
 	virtual void hil_write(uint16_t data) override;
 
 private:
-	// device_serial_interface uses 10'000 range
-	// device_matrix_keyboard_interface uses 20'000 range
-
 	void transmit_byte(uint8_t byte);
 
 	util::fifo<uint8_t, 8> m_fifo;

src/devices/bus/intellec4/intellec4.cpp

@@ -20,17 +20,40 @@ namespace bus { namespace intellec4 {
 univ_slot_device::univ_slot_device(machine_config const &mconfig, char const *tag, device_t *owner, uint32_t clock)
 	: device_t(mconfig, INTELLEC4_UNIV_SLOT, tag, owner, clock)
 	, device_slot_interface(mconfig, *this)
+	, m_bus(*this, finder_base::DUMMY_TAG)
 {
 }
 
 
+/*----------------------------------
+  configuration helpers
+----------------------------------*/
+
 void univ_slot_device::set_bus_tag(device_t &device, char const *tag)
 {
+	downcast<univ_slot_device &>(device).m_bus.set_tag(tag);
 }
 
 
+/*----------------------------------
+  device_t implementation
+----------------------------------*/
+
+void univ_slot_device::device_validity_check(validity_checker &valid) const
+{
+	device_t *const card(get_card_device());
+	if (card && !dynamic_cast<device_univ_card_interface *>(card))
+		osd_printf_error("Card device %s (%s) does not implement device_univ_card_interface\n", card->tag(), card->name());
+}
+
 void univ_slot_device::device_start()
 {
+	device_t *const card_device(get_card_device());
+	device_univ_card_interface *const univ_card(dynamic_cast<device_univ_card_interface *>(card_device));
+	if (card_device && !univ_card)
+		throw emu_fatalerror("univ_slot_device: card device %s (%s) does not implement device_univ_card_interface\n", card_device->tag(), card_device->name());
+	if (univ_card)
+		univ_card->set_bus(*m_bus);
 }
 
 
@@ -39,6 +62,31 @@ void univ_slot_device::device_start()
     BUS DEVICE
 ***********************************************************************/
 
+univ_bus_device::univ_bus_device(machine_config const &mconfig, char const *tag, device_t *owner, uint32_t clock)
+	: device_t(mconfig, INTELLEC4_UNIV_BUS, tag, owner, clock)
+	, m_rom_device(*this, finder_base::DUMMY_TAG)
+	, m_rom_ports_device(*this, finder_base::DUMMY_TAG)
+	, m_memory_device(*this, finder_base::DUMMY_TAG)
+	, m_status_device(*this, finder_base::DUMMY_TAG)
+	, m_ram_ports_device(*this, finder_base::DUMMY_TAG)
+	, m_rom_space(-1)
+	, m_rom_ports_space(-1)
+	, m_memory_space(-1)
+	, m_status_space(-1)
+	, m_ram_ports_space(-1)
+	, m_stop_out_cb(*this)
+	, m_test_out_cb(*this)
+	, m_reset_4002_out_cb(*this)
+	, m_user_reset_out_cb(*this)
+	, m_stop(0U)
+	, m_test(0U)
+	, m_reset_4002(0U)
+	, m_user_reset(0U)
+{
+	std::fill(std::begin(m_cards), std::end(m_cards), nullptr);
+}
+
+
 /*----------------------------------
   address space configuration
 ----------------------------------*/
@@ -79,31 +127,6 @@ void univ_bus_device::set_ram_ports_space(device_t &device, char const *tag, int
 }
 
 
-univ_bus_device::univ_bus_device(machine_config const &mconfig, char const *tag, device_t *owner, uint32_t clock)
-	: device_t(mconfig, INTELLEC4_UNIV_BUS, tag, owner, clock)
-	, m_rom_device(*this, finder_base::DUMMY_TAG)
-	, m_rom_ports_device(*this, finder_base::DUMMY_TAG)
-	, m_memory_device(*this, finder_base::DUMMY_TAG)
-	, m_status_device(*this, finder_base::DUMMY_TAG)
-	, m_ram_ports_device(*this, finder_base::DUMMY_TAG)
-	, m_rom_space(-1)
-	, m_rom_ports_space(-1)
-	, m_memory_space(-1)
-	, m_status_space(-1)
-	, m_ram_ports_space(-1)
-	, m_stop_out_cb(*this)
-	, m_test_out_cb(*this)
-	, m_reset_4002_out_cb(*this)
-	, m_user_reset_out_cb(*this)
-	, m_stop(0U)
-	, m_test(0U)
-	, m_reset_4002(0U)
-	, m_user_reset(0U)
-{
-	std::fill(std::begin(m_cards), std::end(m_cards), nullptr);
-}
-
-
 /*----------------------------------
   input lines
 ----------------------------------*/
@@ -177,6 +200,50 @@ void univ_bus_device::device_start()
 	m_user_reset_out_cb.resolve_safe();
 }
 
+
+/*----------------------------------
+  helpers for cards
+----------------------------------*/
+
+unsigned univ_bus_device::add_card(device_univ_card_interface &card)
+{
+	for (unsigned i = 0; ARRAY_LENGTH(m_cards) > i; ++i)
+	{
+		if (!m_cards[i])
+		{
+			m_cards[i] = &card;
+			return i;
+		}
+	}
+	throw emu_fatalerror("univ_bus_device: maximum number of cards (%u) exceeded\n", unsigned(ARRAY_LENGTH(m_cards)));
+}
+
+
+
+/***********************************************************************
+    CARD INTERFACE
+***********************************************************************/
+
+device_univ_card_interface::device_univ_card_interface(const machine_config &mconfig, device_t &device)
+	: device_slot_card_interface(mconfig, device)
+	, m_bus(nullptr)
+	, m_index(~unsigned(0))
+{
+}
+
+
+void device_univ_card_interface::interface_pre_start()
+{
+	if (!m_bus)
+		throw device_missing_dependencies();
+}
+
+
+void device_univ_card_interface::set_bus(univ_bus_device &bus)
+{
+	m_index = (m_bus = &bus)->add_card(*this);
+}
+
 } } // namespace bus::intellec4
 
 

src/devices/bus/intellec4/intellec4.h

@@ -117,7 +117,7 @@ to implement the card in both systems.
 #define MCFG_INTELLEC4_UNIV_SLOT_ADD(bus_tag, slot_tag, clock, slot_intf, def_slot) \
 		MCFG_DEVICE_ADD(slot_tag, INTELLEC4_UNIV_SLOT, clock) \
 		MCFG_DEVICE_SLOT_INTERFACE(slot_intf, def_slot, false) \
-		bus::intellec4::univ_slot_device::set_bus_tag(*device, bus_tag);
+		bus::intellec4::univ_slot_device::set_bus_tag(*device, "^" bus_tag);
 
 #define MCFG_INTELLEC4_UNIV_SLOT_REMOVE(slot_tag) \
 		MCFG_DEVICE_REMOVE(slot_tag)
@@ -168,13 +168,19 @@ public:
 
 protected:
 	// device_t implementation
+	virtual void device_validity_check(validity_checker &valid) const override ATTR_COLD;
 	virtual void device_start() override;
+
+private:
+	required_device<univ_bus_device>    m_bus;
 };
 
 
 class univ_bus_device : public device_t
 {
 public:
+	friend class device_univ_card_interface;
+
 	// address space configuration
 	static void set_rom_space(device_t &device, char const *tag, int space);
 	static void set_rom_ports_space(device_t &device, char const *tag, int space);
@@ -214,6 +220,9 @@ protected:
 	virtual void device_start() override;
 
 private:
+	// helpers for cards
+	unsigned add_card(device_univ_card_interface &card);
+
 	// finding address spaces
 	required_device<device_memory_interface>    m_rom_device, m_rom_ports_device;
 	required_device<device_memory_interface>    m_memory_device, m_status_device, m_ram_ports_device;
@@ -236,6 +245,20 @@ private:
 
 class device_univ_card_interface : public device_slot_card_interface
 {
+protected:
+	friend class univ_slot_device;
+	friend class univ_bus_device;
+
+	device_univ_card_interface(const machine_config &mconfig, device_t &device);
+
+	// device_interface implementation
+	void interface_pre_start() override;
+
+private:
+	void set_bus(univ_bus_device &bus);
+
+	univ_bus_device *m_bus;
+	unsigned        m_index;
 };
 
 } } // namespace bus::intellec4

src/devices/bus/isa/sblaster.cpp

@@ -1568,13 +1568,10 @@ void sb_device::dack_w(int line, uint8_t data)
 
 void sb_device::device_timer(emu_timer &timer, device_timer_id tid, int param, void *ptr)
 {
-//    printf("DMA timer expire\n");
 	if (tid)
-	{
-		device_serial_interface::device_timer(timer, tid, param, ptr);
 		return;
-	}
 
+//    printf("DMA timer expire\n");
 	uint16_t lsample, rsample;
 	switch (m_dsp.flags) {
 		case 0: // 8-bit unsigned mono

src/devices/bus/nes_ctrl/miracle.cpp

@@ -40,10 +40,6 @@ void nes_miracle_device::device_timer(emu_timer &timer, device_timer_id id, int
 	{
 		m_strobe_clock++;
 	}
-	else
-	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-	}
 }
 
 //**************************************************************************

src/devices/bus/rs232/keyboard.cpp

@@ -47,12 +47,6 @@ WRITE_LINE_MEMBER( serial_keyboard_device::update_serial )
 	reset();
 }
 
-void serial_keyboard_device::device_start()
-{
-	generic_keyboard_device::device_start();
-	device_buffered_serial_interface::register_save_state(machine().save(), this);
-}
-
 void serial_keyboard_device::device_reset()
 {
 	generic_keyboard_device::device_reset();
@@ -79,13 +73,6 @@ void serial_keyboard_device::device_reset()
 	transmit_register_reset();
 }
 
-void serial_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	// give both bases a chance to handle it
-	device_buffered_serial_interface::device_timer(timer, id, param, ptr);
-	generic_keyboard_device::device_timer(timer, id, param, ptr);
-}
-
 void serial_keyboard_device::tra_callback()
 {
 	output_rxd(transmit_register_get_data_bit());

src/devices/bus/rs232/keyboard.h

@@ -27,9 +27,7 @@ public:
 protected:
 	serial_keyboard_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock);
 
-	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void tra_callback() override;
 	virtual void send_key(uint8_t code) override;
 

src/devices/bus/rs232/null_modem.cpp

@@ -89,7 +89,7 @@ void null_modem_device::device_timer(emu_timer &timer, device_timer_id id, int p
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
+		break;
 	}
 }
 

src/devices/bus/rs232/printer.cpp

@@ -67,11 +67,6 @@ WRITE_LINE_MEMBER(serial_printer_device::printer_online)
 	/// TODO: ?
 }
 
-void serial_printer_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 void serial_printer_device::rcv_complete()
 {
 	receive_register_extract();

src/devices/bus/rs232/printer.h

@@ -24,7 +24,6 @@ protected:
 	virtual ioport_constructor device_input_ports() const override;
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	virtual void rcv_complete() override;
 

src/devices/bus/rs232/pty.cpp

@@ -90,7 +90,7 @@ void pseudo_terminal_device::device_timer(emu_timer &timer, device_timer_id id,
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
+		break;
 	}
 }
 

src/devices/bus/rs232/rs232.h

@@ -276,15 +276,12 @@ protected:
 
 	virtual void device_start() override
 	{
-		device_buffered_serial_interface<FIFO_LENGTH>::register_save_state(machine().save(), this);
 	}
 
 	virtual void tra_callback() override
 	{
 		output_rxd(this->transmit_register_get_data_bit());
 	}
-
-	using device_buffered_serial_interface<FIFO_LENGTH>::device_timer;
 };
 
 DECLARE_DEVICE_TYPE(RS232_PORT, rs232_port_device)

src/devices/bus/rs232/ser_mouse.cpp

@@ -86,12 +86,8 @@ void serial_mouse_device::tra_callback()
  **************************************************************************/
 void serial_mouse_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if (id)
+	if (!id)
 	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-		return;
-	}
-
 		static int ox = 0, oy = 0;
 		int nx,ny;
 		int dx, dy, nb;
@@ -123,9 +119,9 @@ void serial_mouse_device::device_timer(emu_timer &timer, device_timer_id id, int
 				mouse_trans(dx, dy, nb, mbc);
 		}
 
-
 		if(m_tail != m_head && is_transmit_register_empty())
 			transmit_register_setup(unqueue_data());
+	}
 }
 
 void microsoft_mouse_device::mouse_trans(int dx, int dy, int nb, int mbc)

src/devices/bus/rs232/terminal.cpp

@@ -32,12 +32,6 @@ ioport_constructor serial_terminal_device::device_input_ports() const
 	return INPUT_PORTS_NAME(serial_terminal);
 }
 
-void serial_terminal_device::device_start()
-{
-	generic_terminal_device::device_start();
-	device_buffered_serial_interface::register_save_state(machine().save(), this);
-}
-
 WRITE_LINE_MEMBER(serial_terminal_device::update_serial)
 {
 	clear_fifo();
@@ -72,12 +66,6 @@ void serial_terminal_device::device_reset()
 	update_serial(0);
 }
 
-void serial_terminal_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	generic_terminal_device::device_timer(timer, id, param, ptr);
-	device_buffered_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 void serial_terminal_device::send_key(uint8_t code)
 {
 	transmit_byte(code);

src/devices/bus/rs232/terminal.h

@@ -20,9 +20,7 @@ public:
 
 protected:
 	virtual ioport_constructor device_input_ports() const override;
-	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	virtual void tra_callback() override;
 	virtual void send_key(uint8_t code) override;

src/devices/bus/rs232/xvd701.cpp

@@ -65,7 +65,7 @@ void jvc_xvd701_device::device_timer(emu_timer &timer, device_timer_id id, int p
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
+		break;
 	}
 }
 

src/devices/bus/snes_ctrl/miracle.cpp

@@ -41,10 +41,6 @@ void snes_miracle_device::device_timer(emu_timer &timer, device_timer_id id, int
 	{
 		m_strobe_clock++;
 	}
-	else
-	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-	}
 }
 
 //**************************************************************************

src/devices/bus/sunkbd/hlekbd.cpp

@@ -802,8 +802,6 @@ MACHINE_CONFIG_END
 
 void hle_device_base::device_start()
 {
-	device_buffered_serial_interface::register_save_state(machine().save(), this);
-
 	m_click_timer = timer_alloc(CLICK_TIMER_ID);
 
 	save_item(NAME(m_make_count));
@@ -874,8 +872,7 @@ void hle_device_base::device_timer(emu_timer &timer, device_timer_id id, int par
 		break;
 
 	default:
-		device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
+		break;
-		device_buffered_serial_interface::device_timer(timer, id, param, ptr);
 	}
 }
 

src/devices/bus/sunkbd/hlekbd.h

@@ -52,8 +52,6 @@ protected:
 	required_ioport m_dips;
 
 private:
-	// device_serial_interface uses 10'000 range
-	// device_matrix_keyboard_interface uses 20'000 range
 	enum {
 		CLICK_TIMER_ID = 30'000
 	};

src/devices/bus/ti8x/graphlinkhle.cpp

@@ -30,8 +30,6 @@ graph_link_hle_device::graph_link_hle_device(
 
 void graph_link_hle_device::device_start()
 {
-	device_serial_interface::register_save_state(machine().save(), this);
-
 	m_buffer = std::make_unique<u8 []>(BUFLEN);
 
 	save_pointer(NAME(m_buffer.get()), BUFLEN);
@@ -51,13 +49,6 @@ void graph_link_hle_device::device_reset()
 }
 
 
-void graph_link_hle_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_ti8x_link_port_byte_interface::device_timer(timer, id, param, ptr);
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
-
 MACHINE_CONFIG_MEMBER(graph_link_hle_device::device_add_mconfig)
 	MCFG_RS232_PORT_ADD("rs232", default_rs232_devices, nullptr)
 	MCFG_RS232_RXD_HANDLER(WRITELINE(graph_link_hle_device, rx_w))

src/devices/bus/ti8x/graphlinkhle.h

@@ -37,7 +37,6 @@ protected:
 	virtual void device_add_mconfig(machine_config &config) override;
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	virtual void byte_collision() override;
 	virtual void byte_send_timeout() override;

src/devices/bus/ti8x/ti8x.cpp

@@ -120,16 +120,23 @@ void device_ti8x_link_port_bit_interface::interface_pre_start()
 {
 	device_ti8x_link_port_interface::interface_pre_start();
 
-	m_error_timer = device().timer_alloc(TIMER_ID_BIT_TIMEOUT);
+	if (!m_error_timer)
+		m_error_timer = device().machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(device_ti8x_link_port_bit_interface::bit_timeout), this));
+
+	m_bit_phase = IDLE;
+	m_tx_bit_buffer = EMPTY;
+	m_tip_in = m_ring_in = true;
+}
+
+
+void device_ti8x_link_port_bit_interface::interface_post_start()
+{
+	device_ti8x_link_port_interface::interface_post_start();
 
 	device().save_item(NAME(m_bit_phase));
 	device().save_item(NAME(m_tx_bit_buffer));
 	device().save_item(NAME(m_tip_in));
 	device().save_item(NAME(m_ring_in));
-
-	m_bit_phase = IDLE;
-	m_tx_bit_buffer = EMPTY;
-	m_tip_in = m_ring_in = true;
 }
 
 
@@ -146,66 +153,6 @@ void device_ti8x_link_port_bit_interface::interface_pre_reset()
 }
 
 
-void device_ti8x_link_port_bit_interface::device_timer(
-		emu_timer &timer,
-		device_timer_id id,
-		int param, void *ptr)
-{
-	switch (id)
-	{
-	case TIMER_ID_BIT_TIMEOUT:
-		switch (m_bit_phase)
-		{
-		// something very bad happened (heap smash?)
-		case IDLE:
-		case HOLD_0:
-		case HOLD_1:
-		default:
-			throw false;
-
-		// receive timeout
-		case ACK_0:
-		case ACK_1:
-			LOGBITPROTO("timeout acknowledging %d bit\n", (ACK_0 == m_bit_phase) ? 0 : 1);
-			output_tip(1);
-			output_ring(1);
-			if (m_tip_in && m_ring_in)
-			{
-				check_tx_bit_buffer();
-			}
-			else
-			{
-				LOGBITPROTO("waiting for bus idle\n");
-				m_error_timer->reset((EMPTY == m_tx_bit_buffer) ? attotime::never : attotime(1, 0)); // TODO: configurable timeout
-				m_bit_phase = WAIT_IDLE;
-			}
-			bit_receive_timeout();
-			break;
-
-		// send timeout:
-		case WAIT_IDLE:
-			assert(EMPTY != m_tx_bit_buffer);
-		case WAIT_ACK_0:
-		case WAIT_ACK_1:
-		case WAIT_REL_0:
-		case WAIT_REL_1:
-			LOGBITPROTO("timeout sending bit\n");
-			m_error_timer->reset();
-			m_bit_phase = (m_tip_in && m_ring_in) ? IDLE : WAIT_IDLE;
-			m_tx_bit_buffer = EMPTY;
-			output_tip(1);
-			output_ring(1);
-			bit_send_timeout();
-			break;
-		}
-		break;
-
-	default:
-		break;
-	}
-}
-
-
 void device_ti8x_link_port_bit_interface::send_bit(bool data)
 {
 	LOGBITPROTO("queue %d bit\n", data ? 1 : 0);
@@ -452,6 +399,55 @@ WRITE_LINE_MEMBER(device_ti8x_link_port_bit_interface::input_ring)
 }
 
 
+TIMER_CALLBACK_MEMBER(device_ti8x_link_port_bit_interface::bit_timeout)
+{
+	switch (m_bit_phase)
+	{
+	// something very bad happened (heap smash?)
+	case IDLE:
+	case HOLD_0:
+	case HOLD_1:
+	default:
+		throw false;
+
+	// receive timeout
+	case ACK_0:
+	case ACK_1:
+		LOGBITPROTO("timeout acknowledging %d bit\n", (ACK_0 == m_bit_phase) ? 0 : 1);
+		output_tip(1);
+		output_ring(1);
+		if (m_tip_in && m_ring_in)
+		{
+			check_tx_bit_buffer();
+		}
+		else
+		{
+			LOGBITPROTO("waiting for bus idle\n");
+			m_error_timer->reset((EMPTY == m_tx_bit_buffer) ? attotime::never : attotime(1, 0)); // TODO: configurable timeout
+			m_bit_phase = WAIT_IDLE;
+		}
+		bit_receive_timeout();
+		break;
+
+	// send timeout:
+	case WAIT_IDLE:
+		assert(EMPTY != m_tx_bit_buffer);
+	case WAIT_ACK_0:
+	case WAIT_ACK_1:
+	case WAIT_REL_0:
+	case WAIT_REL_1:
+		LOGBITPROTO("timeout sending bit\n");
+		m_error_timer->reset();
+		m_bit_phase = (m_tip_in && m_ring_in) ? IDLE : WAIT_IDLE;
+		m_tx_bit_buffer = EMPTY;
+		output_tip(1);
+		output_ring(1);
+		bit_send_timeout();
+		break;
+	}
+}
+
+
 void device_ti8x_link_port_bit_interface::check_tx_bit_buffer()
 {
 	assert(m_tip_in);
@@ -506,10 +502,16 @@ void device_ti8x_link_port_byte_interface::interface_pre_start()
 {
 	device_ti8x_link_port_bit_interface::interface_pre_start();
 
+	m_tx_byte_buffer = m_rx_byte_buffer = 0U;
+}
+
+
+void device_ti8x_link_port_byte_interface::interface_post_start()
+{
+	device_ti8x_link_port_bit_interface::interface_post_start();
+
 	device().save_item(NAME(m_tx_byte_buffer));
 	device().save_item(NAME(m_rx_byte_buffer));
-
-	m_tx_byte_buffer = m_rx_byte_buffer = 0U;
 }
 
 

src/devices/bus/ti8x/ti8x.h

@@ -125,19 +125,13 @@ protected:
 	device_ti8x_link_port_bit_interface(machine_config const &mconfig, device_t &device);
 
 	virtual void interface_pre_start() override;
+	virtual void interface_post_start() override;
 	virtual void interface_pre_reset() override;
 
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr);
-
 	void send_bit(bool data);
 	void accept_bit();
 
 private:
-	enum
-	{
-		TIMER_ID_BIT_TIMEOUT = 20000 // ensure this doesn't clash with device_serial_interface
-	};
-
 	enum bit_phase
 	{
 		IDLE,
@@ -168,6 +162,8 @@ private:
 	virtual void bit_sent() = 0;
 	virtual void bit_received(bool data) = 0;
 
+	TIMER_CALLBACK_MEMBER(bit_timeout);
+
 	void check_tx_bit_buffer();
 
 	emu_timer * m_error_timer;
@@ -183,6 +179,7 @@ protected:
 	device_ti8x_link_port_byte_interface(machine_config const &mconfig, device_t &device);
 
 	virtual void interface_pre_start() override;
+	virtual void interface_post_start() override;
 	virtual void interface_pre_reset() override;
 
 	void send_byte(u8 data);

src/devices/imagedev/midiin.cpp

@@ -64,11 +64,7 @@ void midiin_device::device_reset()
 
 void midiin_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if (id) {
+	if (!id) {
-		device_serial_interface::device_timer(timer, id, param, ptr);
-		return;
-	}
-
 		uint8_t buf[8192*4];
 		int bytesRead;
 
@@ -88,6 +84,7 @@ void midiin_device::device_timer(emu_timer &timer, device_timer_id id, int param
 				}
 			}
 		}
+	}
 }
 
 /*-------------------------------------------------

src/devices/imagedev/midiout.cpp

@@ -47,11 +47,6 @@ void midiout_device::device_reset()
 	set_tra_rate(0);
 }
 
-void midiout_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 /*-------------------------------------------------
     call_load
 -------------------------------------------------*/

src/devices/imagedev/midiout.h

@@ -53,7 +53,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// serial overrides
 	virtual void rcv_complete() override;    // Rx completed receiving byte

src/devices/machine/68561mpcc.cpp

@@ -205,8 +205,6 @@ void mpcc_device::device_start()
 	save_item(NAME(m_ccr));
 	save_item(NAME(m_ecr));
 	LOG(" - MPCC variant %02x\n", m_variant);
-
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 //-------------------------------------------------
@@ -259,11 +257,6 @@ void mpcc_device::device_reset()
 /*
  * Serial device implementation
  */
-void mpcc_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 WRITE_LINE_MEMBER(mpcc_device::cts_w)
 {
 	if (state == CLEAR_LINE)

src/devices/machine/68561mpcc.h

@@ -130,7 +130,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/devices/machine/i8251.cpp

@@ -97,7 +97,6 @@ void i8251_device::device_start()
 	save_item(NAME(m_br_factor));
 	save_item(NAME(m_rx_data));
 	save_item(NAME(m_tx_data));
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 
@@ -678,12 +677,6 @@ READ8_MEMBER(i8251_device::data_r)
 }
 
 
-void i8251_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
-
 WRITE_LINE_MEMBER(i8251_device::write_rxd)
 {
 	m_rxd = state;

src/devices/machine/i8251.h

@@ -91,7 +91,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	void command_w(uint8_t data);
 	void mode_w(uint8_t data);

src/devices/machine/ie15.cpp

@@ -208,8 +208,6 @@ READ8_MEMBER(ie15_device::kb_s_lin_r)
 
 void ie15_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	device_serial_interface::device_timer(timer, id, param, ptr);
-
 	switch (id)
 	{
 	case TIMER_HBLANK:

src/devices/machine/im6402.cpp

@@ -151,16 +151,6 @@ void im6402_device::device_reset()
 }
 
 
-//-------------------------------------------------
-//  device_timer - handler timer events
-//-------------------------------------------------
-
-void im6402_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
-
 //-------------------------------------------------
 //  tra_callback -
 //-------------------------------------------------

src/devices/machine/im6402.h

@@ -114,7 +114,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/devices/machine/ins8250.cpp

@@ -560,7 +560,6 @@ void ins8250_uart_device::device_start()
 	set_tra_rate(0);
 	set_rcv_rate(0);
 
-	device_serial_interface::register_save_state(machine().save(), this);
 	save_item(NAME(m_regs.thr));
 	save_item(NAME(m_regs.rbr));
 	save_item(NAME(m_regs.ier));
@@ -602,11 +601,6 @@ void ins8250_uart_device::device_reset()
 	m_out_out2_cb(1);
 }
 
-void ins8250_uart_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 void ns16550_device::device_start()
 {
 	m_timeout = timer_alloc();
@@ -633,9 +627,7 @@ void ns16550_device::device_reset()
 
 void ns16550_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if(id)
+	if(!id)
-		device_serial_interface::device_timer(timer, id, param, ptr);
-	else
 	{
 		trigger_int(COM_INT_PENDING_CHAR_TIMEOUT);
 		m_timeout->adjust(attotime::never);

src/devices/machine/ins8250.h

@@ -51,7 +51,6 @@ protected:
 	virtual void rcv_complete() override;
 	virtual void tra_complete() override;
 	virtual void tra_callback() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	virtual void set_fcr(uint8_t data) { }
 	virtual void push_tx(uint8_t data) { }

src/devices/machine/keyboard.cpp

@@ -288,12 +288,6 @@ void generic_keyboard_device::device_reset()
 }
 
 
-void generic_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-}
-
-
 void generic_keyboard_device::key_make(u8 row, u8 column)
 {
 	send_translated((row << 4) | column);

src/devices/machine/keyboard.h

@@ -47,7 +47,6 @@ protected:
 
 	virtual void interface_pre_start() override;
 	virtual void interface_post_start() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr);
 
 	void start_processing(const attotime &period);
 	void stop_processing();
@@ -66,13 +65,8 @@ protected:
 	bool are_all_keys_up();
 
 private:
-	// device_serial_interface uses 10'000 range
+	TIMER_CALLBACK_MEMBER(scan_row);
-	enum {
+	TIMER_CALLBACK_MEMBER(typematic);
-		TIMER_ID_SCAN = 20'000,
-		TIMER_ID_TYPEMATIC
-	};
-
-	void scan_row();
 
 	emu_timer       *m_scan_timer;
 	emu_timer       *m_typematic_timer;
@@ -109,7 +103,6 @@ protected:
 			u32 clock);
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(u8 row, u8 column) override;
 	virtual void key_repeat(u8 row, u8 column) override;
 	virtual void send_key(u8 code);

src/devices/machine/keyboard.ipp

@@ -33,8 +33,10 @@ device_matrix_keyboard_interface<ROW_COUNT>::device_matrix_keyboard_interface(ma
 template <uint8_t ROW_COUNT>
 void device_matrix_keyboard_interface<ROW_COUNT>::interface_pre_start()
 {
-	m_scan_timer = device().timer_alloc(TIMER_ID_SCAN);
+	if (!m_scan_timer)
-	m_typematic_timer = device().timer_alloc(TIMER_ID_TYPEMATIC);
+		m_scan_timer = device().machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(device_matrix_keyboard_interface<ROW_COUNT>::scan_row), this));
+	if (!m_typematic_timer)
+		m_typematic_timer = device().machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(device_matrix_keyboard_interface<ROW_COUNT>::typematic), this));
 	reset_key_state();
 	typematic_stop();
 }
@@ -51,22 +53,6 @@ void device_matrix_keyboard_interface<ROW_COUNT>::interface_post_start()
 }
 
 
-template <uint8_t ROW_COUNT>
-void device_matrix_keyboard_interface<ROW_COUNT>::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	switch (id)
-	{
-	case TIMER_ID_SCAN:
-		scan_row();
-		break;
-	case TIMER_ID_TYPEMATIC:
-		assert((m_typematic_row != uint8_t(~0U)) || (m_typematic_column != uint8_t(~0U)));
-		key_repeat(m_typematic_row, m_typematic_column);
-		break;
-	}
-}
-
-
 template <uint8_t ROW_COUNT>
 void device_matrix_keyboard_interface<ROW_COUNT>::start_processing(const attotime &period)
 {
@@ -118,7 +104,7 @@ void device_matrix_keyboard_interface<ROW_COUNT>::typematic_stop()
 
 
 template <uint8_t ROW_COUNT>
-void device_matrix_keyboard_interface<ROW_COUNT>::scan_row()
+TIMER_CALLBACK_MEMBER(device_matrix_keyboard_interface<ROW_COUNT>::scan_row)
 {
 	assert(m_next_row < ARRAY_LENGTH(m_key_rows));
 	assert(m_next_row < ARRAY_LENGTH(m_key_states));
@@ -146,6 +132,14 @@ void device_matrix_keyboard_interface<ROW_COUNT>::scan_row()
 }
 
 
+template <uint8_t ROW_COUNT>
+TIMER_CALLBACK_MEMBER(device_matrix_keyboard_interface<ROW_COUNT>::typematic)
+{
+	assert((m_typematic_row != uint8_t(~0U)) || (m_typematic_column != uint8_t(~0U)));
+	key_repeat(m_typematic_row, m_typematic_column);
+}
+
+
 template <uint8_t ROW_COUNT>
 void device_matrix_keyboard_interface<ROW_COUNT>::key_repeat(uint8_t row, uint8_t column)
 {

src/devices/machine/mc2661.cpp

@@ -492,9 +492,3 @@ READ_LINE_MEMBER( mc2661_device::txemt_r )
 {
 	return (m_sr & STATUS_TXEMT) ? ASSERT_LINE : CLEAR_LINE;
 }
-
-
-void mc2661_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}

src/devices/machine/mc2661.h

@@ -108,7 +108,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/devices/machine/mc6852.cpp

@@ -113,16 +113,6 @@ void mc6852_device::device_reset()
 }
 
 
-//-------------------------------------------------
-//  device_timer - handler timer events
-//-------------------------------------------------
-
-void mc6852_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
-
 //-------------------------------------------------
 //  tra_callback -
 //-------------------------------------------------

src/devices/machine/mc6852.h

@@ -90,7 +90,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int m_param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/devices/machine/mc68681.cpp

@@ -805,11 +805,6 @@ void mc68681_channel::device_reset()
 	CSR = 0;
 }
 
-void mc68681_channel::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 // serial device virtual overrides
 void mc68681_channel::rcv_complete()
 {

src/devices/machine/mc68681.h

@@ -55,7 +55,6 @@ public:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial overrides
 	virtual void rcv_complete() override;    // Rx completed receiving byte

src/devices/machine/mc68901.cpp

@@ -472,8 +472,6 @@ void mc68901_device::device_timer(emu_timer &timer, device_timer_id id, int para
 {
 	if(id >= TIMER_A && id <= TIMER_D)
 		timer_count(id);
-	else
-		device_serial_interface::device_timer(timer, id, param, ptr);
 }
 
 

src/devices/machine/microtch.cpp

@@ -118,12 +118,8 @@ void microtouch_device::send_touch_packet()
 
 void microtouch_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if(id)
+	if (!id)
 	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-		return;
-	}
-
 		if ( m_tx_buffer_ptr < m_tx_buffer_num )
 		{
 			if(is_transmit_register_empty())
@@ -170,6 +166,7 @@ void microtouch_device::device_timer(emu_timer &timer, device_timer_id id, int p
 				}
 			}
 		}
+	}
 }
 
 void microtouch_device::device_start()

src/devices/machine/scnxx562.cpp

@@ -808,8 +808,7 @@ void duscc_channel::device_timer(emu_timer &timer, device_timer_id id, int param
 			m_uart->m_out_trxcb_cb(m_trxc);
 		break;
 	default:
-		LOGR("Unhandled Timer ID passed to device_serial_interface%d\n", id);
+		LOGR("Unhandled Timer ID %d\n", id);
-		device_serial_interface::device_timer(timer, id, param, ptr);
 		break;
 	}
 	//  LOG("%s %d\n", FUNCNAME, id);

src/devices/machine/tms5501.cpp

@@ -152,7 +152,7 @@ void tms5501_device::device_timer(emu_timer &timer, device_timer_id id, int para
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
+		break;
 	}
 }
 

src/devices/machine/z80dart.cpp

@@ -513,7 +513,6 @@ void z80dart_channel::device_start()
 	save_item(NAME(m_dtr));
 	save_item(NAME(m_rts));
 	save_item(NAME(m_sync));
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 
@@ -545,11 +544,6 @@ void z80dart_channel::device_reset()
 	}
 }
 
-void z80dart_channel::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 
 //-------------------------------------------------
 //  tra_callback -

src/devices/machine/z80dart.h

@@ -289,7 +289,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/devices/machine/z80scc.cpp

@@ -969,8 +969,6 @@ void z80scc_channel::device_start()
 	save_item(NAME(m_rts));
 	save_item(NAME(m_tx_int_disarm));
 	save_item(NAME(m_sync_pattern));
-
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 
@@ -1050,10 +1048,6 @@ void z80scc_channel::device_timer(emu_timer &timer, device_timer_id id, int para
 	default:
 		logerror("Spurious timer %d event\n", id);
 	}
-#else
-	// TODO: Hmmm, either the above default clause is called OR the bellow call is not needed  since we handled our local event anyway...?!
-		// and the above default is not called unless we implement the BRG timer using diserial timer interfaces...
-	device_serial_interface::device_timer(timer, id, param, ptr);
 #endif
 }
 

src/devices/machine/z80sio.cpp

@@ -569,7 +569,6 @@ void z80sio_channel::device_start()
 	save_item(NAME(m_rts));
 	save_item(NAME(m_sync));
 	save_item(NAME(m_variant));
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 
@@ -603,11 +602,6 @@ void z80sio_channel::device_reset()
 	}
 }
 
-void z80sio_channel::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 //-------------------------------------------------
 //  tra_callback -
 //-------------------------------------------------

src/devices/machine/z80sio.h

@@ -152,7 +152,6 @@ public:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// device_serial_interface overrides
 	virtual void tra_callback() override;

src/emu/diserial.cpp

@@ -56,40 +56,40 @@ device_serial_interface::~device_serial_interface()
 {
 }
 
-void device_serial_interface::register_save_state(save_manager &save, device_t *device)
-{
-	const char *module = device->name();
-	const char *tag = device->tag();
-	save.save_item(device, module, tag, 0, NAME(m_df_start_bit_count));
-	save.save_item(device, module, tag, 0, NAME(m_df_word_length));
-	save.save_item(device, module, tag, 0, NAME(m_df_parity));
-	save.save_item(device, module, tag, 0, NAME(m_df_stop_bit_count));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_register_data));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_flags));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_bit_count_received));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_bit_count));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_byte_received));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_framing_error));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_parity_error));
-	save.save_item(device, module, tag, 0, NAME(m_tra_register_data));
-	save.save_item(device, module, tag, 0, NAME(m_tra_flags));
-	save.save_item(device, module, tag, 0, NAME(m_tra_bit_count_transmitted));
-	save.save_item(device, module, tag, 0, NAME(m_tra_bit_count));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_rate));
-	save.save_item(device, module, tag, 0, NAME(m_tra_rate));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_line));
-	save.save_item(device, module, tag, 0, NAME(m_tra_clock_state));
-	save.save_item(device, module, tag, 0, NAME(m_rcv_clock_state));
-}
-
 void device_serial_interface::interface_pre_start()
 {
-	m_rcv_clock = device().timer_alloc(RCV_TIMER_ID);
+	if (!m_rcv_clock)
-	m_tra_clock = device().timer_alloc(TRA_TIMER_ID);
+		m_rcv_clock = device().machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(device_serial_interface::rcv_clock), this));
+	if (!m_tra_clock)
+		m_tra_clock = device().machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(device_serial_interface::tra_clock), this));
 	m_rcv_clock_state = false;
 	m_tra_clock_state = false;
 }
 
+void device_serial_interface::interface_post_start()
+{
+	device().save_item(NAME(m_df_start_bit_count));
+	device().save_item(NAME(m_df_word_length));
+	device().save_item(NAME(m_df_parity));
+	device().save_item(NAME(m_df_stop_bit_count));
+	device().save_item(NAME(m_rcv_register_data));
+	device().save_item(NAME(m_rcv_flags));
+	device().save_item(NAME(m_rcv_bit_count_received));
+	device().save_item(NAME(m_rcv_bit_count));
+	device().save_item(NAME(m_rcv_byte_received));
+	device().save_item(NAME(m_rcv_framing_error));
+	device().save_item(NAME(m_rcv_parity_error));
+	device().save_item(NAME(m_tra_register_data));
+	device().save_item(NAME(m_tra_flags));
+	device().save_item(NAME(m_tra_bit_count_transmitted));
+	device().save_item(NAME(m_tra_bit_count));
+	device().save_item(NAME(m_rcv_rate));
+	device().save_item(NAME(m_tra_rate));
+	device().save_item(NAME(m_rcv_line));
+	device().save_item(NAME(m_tra_clock_state));
+	device().save_item(NAME(m_rcv_clock_state));
+}
+
 void device_serial_interface::set_rcv_rate(const attotime &rate)
 {
 	m_rcv_rate = rate/2;
@@ -153,14 +153,6 @@ WRITE_LINE_MEMBER(device_serial_interface::clock_w)
 	rx_clock_w(state);
 }
 
-void device_serial_interface::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	switch(id) {
-	case TRA_TIMER_ID: tx_clock_w(!m_tra_clock_state); break;
-	case RCV_TIMER_ID: rx_clock_w(!m_rcv_clock_state); break;
-	}
-}
-
 
 void device_serial_interface::set_data_frame(int start_bit_count, int data_bit_count, parity_t parity, stop_bits_t stop_bits)
 {

src/emu/diserial.h

@@ -123,19 +123,16 @@ protected:
 
 	// interface-level overrides
 	virtual void interface_pre_start() override;
-
+	virtual void interface_post_start() override;
-	// Must be called from device_timer in the underlying device
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr);
 
 	bool m_start_bit_hack_for_external_clocks;
 
 	const char *parity_tostring(parity_t stop_bits);
 	const char *stop_bits_tostring(stop_bits_t stop_bits);
 
-	void register_save_state(save_manager &save, device_t *device);
-
 private:
-	enum { TRA_TIMER_ID = 10000, RCV_TIMER_ID };
+	TIMER_CALLBACK_MEMBER(rcv_clock) { rx_clock_w(!m_rcv_clock_state); }
+	TIMER_CALLBACK_MEMBER(tra_clock) { tx_clock_w(!m_tra_clock_state); }
 
 	u8 m_serial_parity_table[256];
 
@@ -246,17 +243,15 @@ protected:
 		return !m_empty && (m_head == m_tail);
 	}
 
-	void register_save_state(save_manager &save, device_t *device)
+protected:
+	void interface_post_start() override
 	{
-		device_serial_interface::register_save_state(save, device);
+		device_serial_interface::interface_post_start();
 
-		char const *const module(device->name());
+		device().save_item(NAME(m_fifo));
-		char const *const tag(device->tag());
+		device().save_item(NAME(m_head));
-
+		device().save_item(NAME(m_tail));
-		save.save_item(device, module, tag, 0, NAME(m_fifo));
+		device().save_item(NAME(m_empty));
-		save.save_item(device, module, tag, 0, NAME(m_head));
-		save.save_item(device, module, tag, 0, NAME(m_tail));
-		save.save_item(device, module, tag, 0, NAME(m_empty));
 	}
 
 private:

src/emu/dislot.h

@@ -143,7 +143,7 @@ public:
 	const std::unordered_map<std::string, std::unique_ptr<device_slot_option>> &option_list() const { return m_options; }
 	device_slot_option *option(const char *name) const;
 	virtual std::string get_default_card_software(get_default_card_software_hook &hook) const { return std::string(); }
-	device_t *get_card_device() { return m_card_device; }
+	device_t *get_card_device() const { return m_card_device; }
 	void set_card_device(device_t *dev) { m_card_device = dev; }
 	const char *slot_name() const { return device().tag() + 1; }
 

src/mame/drivers/px4.cpp

@@ -144,8 +144,6 @@ protected:
 	virtual void rcv_callback() override;
 	virtual void rcv_complete() override;
 
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
-
 private:
 	// z80 interrupt sources
 	enum
@@ -827,11 +825,6 @@ WRITE_LINE_MEMBER( px4_state::rs232_cts_w )
 	m_rs232_cts = state;
 }
 
-void px4_state::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 void px4_state::tra_callback()
 {
 	if (ART_TX_ENABLED)

src/mame/drivers/seta2.cpp

@@ -705,7 +705,6 @@ void funcube_touchscreen_device::device_start()
 	save_item(NAME(m_button_state));
 	save_item(NAME(m_serial_pos));
 	save_item(NAME(m_serial));
-	device_serial_interface::register_save_state(machine().save(), this);
 }
 
 void funcube_touchscreen_device::device_reset()
@@ -717,11 +716,7 @@ void funcube_touchscreen_device::device_reset()
 
 void funcube_touchscreen_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if(id) {
+	if(!id) {
-		device_serial_interface::device_timer(timer, id, param, ptr);
-		return;
-	}
-
 		uint8_t button_state = m_btn->read();
 		if(m_button_state != button_state) {
 			m_button_state = button_state;
@@ -732,6 +727,7 @@ void funcube_touchscreen_device::device_timer(emu_timer &timer, device_timer_id
 			m_serial_pos = 0;
 			transmit_register_setup(m_serial[m_serial_pos++]);
 		}
+	}
 }
 
 void funcube_touchscreen_device::tra_complete()

src/mame/includes/osborne1.h

@@ -28,12 +28,6 @@
 class osborne1_state : public driver_device
 {
 public:
-	enum
-	{
-		TIMER_VIDEO,
-		TIMER_ACIA_RXC_TXC
-	};
-
 	osborne1_state(const machine_config &mconfig, device_type type, const char *tag) :
 		driver_device(mconfig, type, tag),
 		m_maincpu(*this, "maincpu"),
@@ -102,8 +96,8 @@ public:
 	required_device<floppy_connector>       m_floppy1;
 
 protected:
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	TIMER_CALLBACK_MEMBER(video_callback);
+	TIMER_CALLBACK_MEMBER(acia_rxc_txc_callback);
 
 	TILE_GET_INFO_MEMBER(get_tile_info);
 

src/mame/machine/apollo_kbd.cpp

@@ -127,11 +127,6 @@ void apollo_kbd_device::device_reset()
 	m_xmit_read = m_xmit_write = 0;
 }
 
-void apollo_kbd_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
 /***************************************************************************
  cpu_context - return a string describing the current CPU context
  ***************************************************************************/

src/mame/machine/apollo_kbd.h

@@ -58,7 +58,6 @@ private:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// serial overrides
 	virtual void rcv_complete() override;    // Rx completed receiving byte

src/mame/machine/dec_lk201.cpp

@@ -589,8 +589,8 @@ void lk201_device::device_timer(emu_timer &timer, device_timer_id id, int param,
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
+		break;
-}
+	}
 }
 
 

src/mame/machine/esqpanel.cpp

@@ -483,10 +483,6 @@ void esqpanel_device::device_timer(emu_timer &timer, device_timer_id id, int par
 	{
 		check_external_panel_server();
 	}
-	else
-	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-	}
 }
 
 void esqpanel_device::rcv_complete()    // Rx completed receiving byte

src/mame/machine/gridkeyb.cpp

@@ -241,12 +241,6 @@ void grid_keyboard_device::device_reset()
 }
 
 
-void grid_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-}
-
-
 void grid_keyboard_device::key_make(u8 row, u8 column)
 {
 	send_translated((row << 4) | column);

src/mame/machine/gridkeyb.h

@@ -65,7 +65,6 @@ protected:
 			u32 clock);
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(u8 row, u8 column) override;
 	virtual void key_repeat(u8 row, u8 column) override;
 	virtual void send_key(u16 code);

src/mame/machine/m20_kbd.cpp

@@ -189,13 +189,6 @@ void m20_keyboard_device::device_reset()
 }
 
 
-void m20_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	buffered_rs232_device::device_timer(timer, id, param, ptr);
-}
-
-
 void m20_keyboard_device::key_make(uint8_t row, uint8_t column)
 {
 	uint8_t const row_code(((row < 6U) ? row : (0x18U | (row - 6U))) << 3);

src/mame/machine/m20_kbd.h

@@ -14,7 +14,6 @@ public:
 
 protected:
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(uint8_t row, uint8_t column) override;
 
 private:

src/mame/machine/midikbd.cpp

@@ -15,11 +15,7 @@ midi_keyboard_device::midi_keyboard_device(const machine_config &mconfig, const
 
 void midi_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if(id)
+	if(!id)
-	{
-		device_serial_interface::device_timer(timer, id, param, ptr);
-	}
-	else
 	{
 		const int keyboard_notes[24] =
 		{

src/mame/machine/octo_kbd.cpp

@@ -253,11 +253,5 @@ void octopus_keyboard_device::device_reset()
 	start_processing(attotime::from_hz(9600));
 }
 
-void octopus_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	buffered_rs232_device::device_timer(timer, id, param, ptr);
-}
-
 
 DEFINE_DEVICE_TYPE(OCTOPUS_KEYBOARD, octopus_keyboard_device, "octopus_kb", "Octopus Keyboard")

src/mame/machine/octo_kbd.h

@@ -16,7 +16,6 @@ public:
 protected:
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(uint8_t row, uint8_t column) override;
 	virtual void key_repeat(uint8_t row, uint8_t column) override;
 	virtual void key_break(uint8_t row, uint8_t column) override;

src/mame/machine/osborne1.cpp

@@ -267,13 +267,13 @@ DRIVER_INIT_MEMBER( osborne1_state, osborne1 )
 	m_bank_fxxx->configure_entries(0, 1, m_ram->pointer() + 0xF000, 0);
 	m_bank_fxxx->configure_entries(1, 1, m_ram->pointer() + 0x10000, 0);
 
-	m_video_timer = timer_alloc(TIMER_VIDEO);
+	m_video_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(osborne1_state::video_callback), this));
 	m_tilemap = &machine().tilemap().create(
 			*m_gfxdecode,
 			tilemap_get_info_delegate(FUNC(osborne1_state::get_tile_info), this), TILEMAP_SCAN_ROWS,
 			8, 10, 128, 32);
 
-	m_acia_rxc_txc_timer = timer_alloc(TIMER_ACIA_RXC_TXC);
+	m_acia_rxc_txc_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(osborne1_state::acia_rxc_txc_callback), this));
 
 	save_item(NAME(m_screen_pac));
 	save_item(NAME(m_acia_rxc_txc_div));
@@ -357,22 +357,6 @@ uint32_t osborne1_state::screen_update(screen_device &screen, bitmap_ind16 &bitm
 }
 
 
-void osborne1_state::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	switch (id)
-	{
-	case TIMER_VIDEO:
-		video_callback(ptr, param);
-		break;
-	case TIMER_ACIA_RXC_TXC:
-		m_acia_rxc_txc_state = m_acia_rxc_txc_state ? 0 : 1;
-		update_acia_rxc_txc();
-		break;
-	default:
-		assert_always(false, "Unknown id in osborne1_state::device_timer");
-	}
-}
-
 TIMER_CALLBACK_MEMBER(osborne1_state::video_callback)
 {
 	int const y = machine().first_screen()->vpos();
@@ -451,6 +435,12 @@ TIMER_CALLBACK_MEMBER(osborne1_state::video_callback)
 	m_video_timer->adjust(machine().first_screen()->time_until_pos(y + 1, 0));
 }
 
+TIMER_CALLBACK_MEMBER(osborne1_state::acia_rxc_txc_callback)
+{
+	m_acia_rxc_txc_state = m_acia_rxc_txc_state ? 0 : 1;
+	update_acia_rxc_txc();
+}
+
 
 TILE_GET_INFO_MEMBER(osborne1_state::get_tile_info)
 {

src/mame/machine/qx10kbd.cpp

@@ -36,13 +36,6 @@ void qx10_keyboard_device::device_reset()
 }
 
 
-void qx10_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	buffered_rs232_device::device_timer(timer, id, param, ptr);
-}
-
-
 void qx10_keyboard_device::key_make(uint8_t row, uint8_t column)
 {
 	transmit_byte((column << 4) | row);

src/mame/machine/qx10kbd.h

@@ -17,7 +17,6 @@ public:
 
 protected:
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(uint8_t row, uint8_t column) override;
 
 private:

src/mame/machine/rmnkbd.cpp

@@ -153,13 +153,6 @@ void rmnimbus_keyboard_device::device_reset()
 }
 
 
-void rmnimbus_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	buffered_rs232_device::device_timer(timer, id, param, ptr);
-}
-
-
 void rmnimbus_keyboard_device::key_make(uint8_t row, uint8_t column)
 {
 	transmit_byte((row << 3) | column);

src/mame/machine/rmnkbd.h

@@ -14,7 +14,6 @@ public:
 
 protected:
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(uint8_t row, uint8_t column) override;
 	virtual void key_break(uint8_t row, uint8_t column) override;
 

src/mame/machine/wangpckb.cpp

@@ -406,16 +406,6 @@ void wangpc_keyboard_device::device_reset()
 }
 
 
-//-------------------------------------------------
-//  device_timer - handler timer events
-//-------------------------------------------------
-
-void wangpc_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}
-
-
 //-------------------------------------------------
 //  tra_callback -
 //-------------------------------------------------

src/mame/machine/wangpckb.h

@@ -63,7 +63,6 @@ protected:
 	// device-level overrides
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	// optional information overrides
 	virtual const tiny_rom_entry *device_rom_region() const override;

src/mame/machine/x68k_kbd.cpp

@@ -295,12 +295,6 @@ void x68k_keyboard_device::device_reset()
 	output_rxd(1);
 }
 
-void x68k_keyboard_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_matrix_keyboard_interface::device_timer(timer, id, param, ptr);
-	buffered_rs232_device::device_timer(timer, id, param, ptr);
-}
-
 
 DEFINE_DEVICE_TYPE(X68K_KEYBOARD, x68k_keyboard_device, "x68k_keyboard", "Sharp X68000 Keyboard")
 

src/mame/machine/x68k_kbd.h

@@ -14,7 +14,6 @@ public:
 protected:
 	virtual void device_start() override;
 	virtual void device_reset() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void key_make(uint8_t row, uint8_t column) override;
 	virtual void key_repeat(uint8_t row, uint8_t column) override;
 	virtual void key_break(uint8_t row, uint8_t column) override;

src/mame/machine/zx8302.cpp

@@ -238,7 +238,6 @@ void zx8302_device::device_timer(emu_timer &timer, device_timer_id id, int param
 		break;
 
 	default:
-		device_serial_interface::device_timer(timer, id, param, ptr);
 		break;
 	}
 }

src/mame/video/pcd.cpp

@@ -468,8 +468,3 @@ void pcx_video_device::rcv_complete()
 	m_mcu->set_input_line(MCS51_RX_LINE, ASSERT_LINE);
 	m_mcu->set_input_line(MCS51_RX_LINE, CLEAR_LINE);
 }
-
-void pcx_video_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
-{
-	device_serial_interface::device_timer(timer, id, param, ptr);
-}

src/mame/video/pcd.h

@@ -100,7 +100,6 @@ protected:
 	void device_reset() override;
 	virtual const tiny_rom_entry *device_rom_region() const override;
 	virtual void device_add_mconfig(machine_config &config) override;
-	void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
 	void tra_callback() override;
 	void rcv_complete() override;