pic8259: Emulate three-cycle acknowledge for non-8086 mode

src/devices/machine/i82357.cpp

@@ -46,12 +46,12 @@ void i82357_device::device_add_mconfig(machine_config &config)
 	PIC8259(config, m_pic[0], 0);
 	m_pic[0]->in_sp_callback().set_constant(1);
 	m_pic[0]->read_slave_ack_callback().set(
-		[this](offs_t offset)
+		[this](offs_t offset) -> u8
 		{
 			if (offset == 2)
 				return m_pic[1]->acknowledge();
 
-			return u32(0);
+			return 0;
 		});
 
 	PIC8259(config, m_pic[1], 0);

src/devices/machine/pic8259.cpp

@@ -39,14 +39,15 @@ void pic8259_device::device_timer(emu_timer &timer, device_timer_id id, int para
 		/* is this IRQ in service and not cascading and sfnm? */
 		if ((m_isr & mask) && !(m_master && m_cascade && m_nested && (m_slave & mask)))
 		{
-			LOG("pic8259_timerproc(): PIC IRQ #%d still in service\n", irq);
+			LOG("pic8259_timerproc(): PIC IR%d still in service\n", irq);
 			break;
 		}
 
 		/* is this IRQ pending and enabled? */
 		if ((m_state == state_t::READY) && (m_irr & mask) && !(m_imr & mask))
 		{
-			LOG("pic8259_timerproc(): PIC triggering IRQ #%d\n", irq);
+			LOG("pic8259_timerproc(): PIC triggering IR%d\n", irq);
+			m_current_level = irq;
 			m_out_int_func(1);
 			return;
 		}
@@ -54,6 +55,7 @@ void pic8259_device::device_timer(emu_timer &timer, device_timer_id id, int para
 		if((m_isr & mask) && m_master && m_cascade && m_nested && (m_slave & mask))
 			break;
 	}
+	m_current_level = -1;
 	m_out_int_func(0);
 }
 
@@ -64,7 +66,7 @@ void pic8259_device::set_irq_line(int irq, int state)
 	if (state)
 	{
 		/* setting IRQ line */
-		LOG("set_irq_line(): PIC set IRQ line #%d\n", irq);
+		LOG("set_irq_line(): PIC set IR%d line\n", irq);
 
 		if(m_level_trig_mode || (!m_level_trig_mode && !(m_irq_lines & mask)))
 		{
@@ -75,26 +77,28 @@ void pic8259_device::set_irq_line(int irq, int state)
 	else
 	{
 		/* clearing IRQ line */
-		LOG("set_irq_line(): PIC cleared IRQ line #%d\n", irq);
+		LOG("set_irq_line(): PIC cleared IR%d line\n", irq);
 
 		m_irq_lines &= ~mask;
 		m_irr &= ~mask;
 	}
-	set_timer();
+
+	if (m_inta_sequence == 0)
+		set_timer();
 }
 
 
-uint32_t pic8259_device::acknowledge()
+uint8_t pic8259_device::acknowledge()
 {
-	for (int n = 0, irq = m_prio; n < 8; n++, irq = (irq + 1) & 7)
+	if (is_x86())
 	{
-		uint8_t mask = 1 << irq;
-
 		/* is this IRQ pending and enabled? */
-		if ((m_irr & mask) && !(m_imr & mask))
+		if (m_current_level != -1)
 		{
-			if (!machine().side_effects_disabled()) {
+			uint8_t mask = 1 << m_current_level;
-				LOG("pic8259_acknowledge(): PIC acknowledge IRQ #%d\n", irq);
+			if (!machine().side_effects_disabled())
+			{
+				LOG("pic8259_acknowledge(): PIC acknowledge IR%d\n", m_current_level);
 				if (!m_level_trig_mode)
 					m_irr &= ~mask;
 
@@ -107,29 +111,70 @@ uint32_t pic8259_device::acknowledge()
 			if ((m_cascade!=0) && (m_master!=0) && (mask & m_slave))
 			{
 				// it's from slave device
-				return m_read_slave_ack_func(irq);
+				return m_read_slave_ack_func(m_current_level);
 			}
 			else
 			{
-				if (is_x86())
+				/* For x86 mode*/
-				{
+				return m_current_level + m_base;
-					/* For x86 mode*/
-					return irq + m_base;
-				}
-				else
-				{
-					/* in case of 8080/85) */
-					return 0xcd0000 + (m_vector_addr_high << 8) + m_vector_addr_low + (irq << (3-m_vector_size));
-				}
 			}
 		}
+		else
+		{
+			if (!machine().side_effects_disabled())
+				logerror("Spurious INTA\n");
+			return m_base + 7;
+		}
 	}
-	if (!machine().side_effects_disabled())
-		logerror("Spurious IRQ\n");
-	if (is_x86())
-		return m_base + 7;
 	else
-		return 0xcd0000 + (m_vector_addr_high << 8) + m_vector_addr_low + (7 << (3-m_vector_size));
+	{
+		/* in case of 8080/85 */
+		if (m_inta_sequence == 0)
+		{
+			if (!machine().side_effects_disabled())
+			{
+				if (m_current_level != -1)
+				{
+					LOG("pic8259_acknowledge(): PIC acknowledge IR%d\n", m_current_level);
+
+					uint8_t mask = 1 << m_current_level;
+					if (!m_level_trig_mode)
+						m_irr &= ~mask;
+					m_isr |= mask;
+				}
+				else
+					logerror("Spurious INTA\n");
+				m_inta_sequence = 1;
+			}
+			if (m_cascade && m_master && m_current_level != -1 && BIT(m_slave, m_current_level))
+				return m_read_slave_ack_func(m_current_level);
+			else
+				return 0xcd;
+		}
+		else if (m_inta_sequence == 1)
+		{
+			if (!machine().side_effects_disabled())
+				m_inta_sequence = 2;
+			if (m_cascade && m_master && m_current_level != -1 && BIT(m_slave, m_current_level))
+				return m_read_slave_ack_func(m_current_level);
+			else
+				return m_vector_addr_low + ((m_current_level & 7) << (3-m_vector_size));
+		}
+		else
+		{
+			if (!machine().side_effects_disabled())
+			{
+				m_inta_sequence = 0;
+				if (m_auto_eoi && m_current_level != -1)
+					m_isr &= ~(1 << m_current_level);
+				set_timer();
+			}
+			if (m_cascade && m_master && m_current_level != -1 && BIT(m_slave, m_current_level))
+				return m_read_slave_ack_func(m_current_level);
+			else
+				return m_vector_addr_high;
+		}
+	}
 }
 
 
@@ -138,6 +183,15 @@ IRQ_CALLBACK_MEMBER(pic8259_device::inta_cb)
 	return acknowledge();
 }
 
+IRQ_CALLBACK_MEMBER(pic8259_device::inta_call)
+{
+	// FIXME: make 8085 and Z80 devices read CALL vectors one byte at a time, not all at once
+	uint32_t vector = acknowledge() << 16;
+	vector |= acknowledge();
+	vector |= acknowledge() << 8;
+	return vector;
+}
+
 
 uint8_t pic8259_device::read(offs_t offset)
 {
@@ -150,18 +204,17 @@ uint8_t pic8259_device::read(offs_t offset)
 			if ( m_ocw3 & 0x04 )
 			{
 				/* Polling mode */
-				if ( m_irr & ~m_imr )
+				if (m_current_level != -1)
 				{
-					/* check the various IRQs */
+					data = 0x80 | m_current_level;
-					for (int n = 0, irq = m_prio; n < 8; n++, irq = (irq + 1) & 7)
+
-					{
+					if (!m_level_trig_mode)
-						if ( ( 1 << irq ) & m_irr & ~m_imr )
+						m_irr &= ~(1 << m_current_level);
-						{
+
-							data = 0x80 | irq;
+					if (!m_auto_eoi)
-							break;
+						m_isr |= 1 << m_current_level;
-						}
+
-					}
+					set_timer();
-					acknowledge();
 				}
 			}
 			else
@@ -207,7 +260,9 @@ void pic8259_device::write(offs_t offset, uint8_t data)
 				m_cascade            = (data & 0x02) ? 0 : 1;
 				m_icw4_needed        = (data & 0x01) ? 1 : 0;
 				m_vector_addr_low    = (data & 0xe0);
-				m_state          = state_t::ICW2;
+				m_state              = state_t::ICW2;
+				m_current_level      = -1;
+				m_inta_sequence      = 0;
 				m_out_int_func(0);
 			}
 			else if (m_state == state_t::READY)
@@ -377,6 +432,8 @@ void pic8259_device::device_start()
 	save_item(NAME(m_mode));
 	save_item(NAME(m_auto_eoi));
 	save_item(NAME(m_is_x86));
+	save_item(NAME(m_current_level));
+	save_item(NAME(m_inta_sequence));
 }
 
 
@@ -406,6 +463,8 @@ void pic8259_device::device_reset()
 	m_is_x86 = 0;
 	m_vector_addr_low = 0;
 	m_vector_addr_high = 0;
+	m_current_level = -1;
+	m_inta_sequence = 0;
 
 	m_master = m_in_sp_func();
 }

src/devices/machine/pic8259.h

@@ -39,7 +39,7 @@ public:
 
 	uint8_t read(offs_t offset);
 	void write(offs_t offset, uint8_t data);
-	uint32_t acknowledge();
+	uint8_t acknowledge();
 
 	DECLARE_WRITE_LINE_MEMBER( ir0_w ) { set_irq_line(0, state); }
 	DECLARE_WRITE_LINE_MEMBER( ir1_w ) { set_irq_line(1, state); }
@@ -51,6 +51,7 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( ir7_w ) { set_irq_line(7, state); }
 
 	IRQ_CALLBACK_MEMBER(inta_cb);
+	IRQ_CALLBACK_MEMBER(inta_call);
 
 protected:
 	pic8259_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock);
@@ -81,7 +82,7 @@ private:
 
 	devcb_write_line m_out_int_func;
 	devcb_read_line m_in_sp_func;
-	devcb_read32 m_read_slave_ack_func;
+	devcb_read8 m_read_slave_ack_func;
 
 	state_t m_state;
 
@@ -113,6 +114,9 @@ private:
 	uint8_t m_mode;
 	uint8_t m_auto_eoi;
 	uint8_t m_is_x86;
+
+	int8_t m_current_level;
+	uint8_t m_inta_sequence;
 };
 
 class v5x_icu_device : public pic8259_device

src/mame/drivers/b2m.cpp

@@ -193,7 +193,7 @@ void b2m_state::b2m(machine_config &config)
 	m_maincpu->set_addrmap(AS_PROGRAM, &b2m_state::b2m_mem);
 	m_maincpu->set_addrmap(AS_IO, &b2m_state::b2m_io);
 	m_maincpu->set_vblank_int("screen", FUNC(b2m_state::b2m_vblank_interrupt));
-	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_call));
 
 	/* video hardware */
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER));

src/mame/drivers/dvk_ksm.cpp

@@ -416,7 +416,7 @@ void ksm_state::ksm(machine_config &config)
 	I8080(config, m_maincpu, XTAL(15'400'000)/10);
 	m_maincpu->set_addrmap(AS_PROGRAM, &ksm_state::ksm_mem);
 	m_maincpu->set_addrmap(AS_IO, &ksm_state::ksm_io);
-	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_call));
 
 	TIMER(config, "scantimer").configure_scanline(FUNC(ksm_state::scanline_callback), "screen", 0, 1);
 

src/mame/drivers/fastinvaders.cpp

@@ -634,7 +634,7 @@ void fastinvaders_state::fastinvaders(machine_config &config)
 //  m_maincpu->set_addrmap(AS_IO, &fastinvaders_state::fastinvaders_io_map);
 //  m_maincpu->set_vblank_int("screen", FUNC(fastinvaders_state::irq0_line_hold));
 	m_maincpu->in_sid_func().set(FUNC(fastinvaders_state::sid_read));
-	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_call));
 
 	TIMER(config, "scantimer").configure_scanline(FUNC(fastinvaders_state::scanline_timer), "screen", 0, 1);
 

src/mame/drivers/imds2.cpp

@@ -258,7 +258,7 @@ void imds2_state::imds2(machine_config &config)
 	I8085A(config, m_ipccpu, IPC_XTAL_Y2);  // CLK OUT = 4 MHz
 	m_ipccpu->set_addrmap(AS_PROGRAM, &imds2_state::ipc_mem_map);
 	m_ipccpu->set_addrmap(AS_IO, &imds2_state::ipc_io_map);
-	m_ipccpu->set_irq_acknowledge_callback("ipcsyspic", FUNC(pic8259_device::inta_cb));
+	m_ipccpu->set_irq_acknowledge_callback("ipcsyspic", FUNC(pic8259_device::inta_call));
 	//config.set_maximum_quantum(attotime::from_hz(100));
 
 	PIC8259(config, m_ipcsyspic, 0);
@@ -267,7 +267,7 @@ void imds2_state::imds2(machine_config &config)
 
 	PIC8259(config, m_ipclocpic, 0);
 	m_ipclocpic->out_int_callback().set(m_ipcsyspic, FUNC(pic8259_device::ir7_w));
-	m_ipclocpic->in_sp_callback().set_constant(1);
+	m_ipclocpic->in_sp_callback().set_constant(0);
 
 	PIT8253(config, m_ipctimer, 0);
 	m_ipctimer->set_clk<0>(IPC_XTAL_Y1 / 16);

src/mame/drivers/iq151.cpp

@@ -395,7 +395,7 @@ void iq151_state::iq151(machine_config &config)
 	m_maincpu->set_addrmap(AS_PROGRAM, &iq151_state::iq151_mem);
 	m_maincpu->set_addrmap(AS_IO, &iq151_state::iq151_io);
 	m_maincpu->set_vblank_int("screen", FUNC(iq151_state::iq151_vblank_interrupt));
-	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_call));
 
 	/* video hardware */
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER, rgb_t::green()));

src/mame/drivers/isbc8030.cpp

@@ -90,6 +90,7 @@ void isbc8030_state::isbc8030(machine_config &config)
 	I8085A(config, m_maincpu, XTAL(22'118'400) / 4);
 	m_maincpu->set_addrmap(AS_PROGRAM, &isbc8030_state::isbc8030_mem);
 	m_maincpu->set_addrmap(AS_IO, &isbc8030_state::isbc8030_io);
+	m_maincpu->set_irq_acknowledge_callback(m_pic, FUNC(pic8259_device::inta_call));
 
 	PIC8259(config, m_pic, 0);
 	m_pic->out_int_callback().set_inputline(m_maincpu, 0);

src/mame/drivers/juku.cpp

@@ -456,7 +456,7 @@ void juku_state::juku(machine_config &config)
 	I8080A(config, m_maincpu, 2000000);
 	m_maincpu->set_addrmap(AS_PROGRAM, &juku_state::mem_map);
 	m_maincpu->set_addrmap(AS_IO, &juku_state::io_map);
-	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_call));
 
 	ADDRESS_MAP_BANK(config, m_bank);
 	m_bank->set_map(&juku_state::bank_map);

src/mame/drivers/okean240.cpp

@@ -513,6 +513,7 @@ void okean240_state::okean240t(machine_config &config)
 	I8080(config, m_maincpu, XTAL(12'000'000) / 6);
 	m_maincpu->set_addrmap(AS_PROGRAM, &okean240_state::okean240_mem);
 	m_maincpu->set_addrmap(AS_IO, &okean240_state::okean240t_io);
+	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_call));
 
 	i8251_device &uart(I8251(config, "uart", 0));
 	uart.txd_handler().set("rs232", FUNC(rs232_port_device::write_txd));

src/mame/drivers/olyboss.cpp

@@ -255,7 +255,7 @@ WRITE_LINE_MEMBER( olyboss_state::romdis_w )
 IRQ_CALLBACK_MEMBER( olyboss_state::irq_cb )
 {
 	if(!irqline)
-		return m_pic->acknowledge();
+		return m_pic->inta_call(device, 0);
 	return 0;
 }
 

src/mame/drivers/pk8020.cpp

@@ -241,7 +241,7 @@ void pk8020_state::pk8020(machine_config &config)
 	m_maincpu->set_addrmap(AS_PROGRAM, &pk8020_state::pk8020_mem);
 	m_maincpu->set_addrmap(AS_IO, &pk8020_state::pk8020_io);
 	m_maincpu->set_vblank_int("screen", FUNC(pk8020_state::pk8020_interrupt));
-	m_maincpu->set_irq_acknowledge_callback("inr", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("inr", FUNC(pic8259_device::inta_call));
 
 	PLS100(config, m_decplm); // КР556РТ2 (82S100 equivalent; D31)
 

src/mame/drivers/qx10.cpp

@@ -113,7 +113,7 @@ private:
 	DECLARE_WRITE_LINE_MEMBER( tc_w );
 	DECLARE_READ8_MEMBER( mc146818_r );
 	DECLARE_WRITE8_MEMBER( mc146818_w );
-	DECLARE_READ32_MEMBER( get_slave_ack );
+	uint8_t get_slave_ack(offs_t offset);
 	DECLARE_READ8_MEMBER( vram_bank_r );
 	DECLARE_WRITE8_MEMBER( vram_bank_w );
 	DECLARE_READ16_MEMBER( vram_r );
@@ -504,7 +504,7 @@ WRITE_LINE_MEMBER(qx10_state::keyboard_clk)
     IR7     Slave cascade
 */
 
-READ32_MEMBER( qx10_state::get_slave_ack )
+uint8_t qx10_state::get_slave_ack(offs_t offset)
 {
 	if (offset==7) { // IRQ = 7
 		return m_pic_s->acknowledge();
@@ -727,7 +727,7 @@ void qx10_state::qx10(machine_config &config)
 	Z80(config, m_maincpu, MAIN_CLK / 4);
 	m_maincpu->set_addrmap(AS_PROGRAM, &qx10_state::qx10_mem);
 	m_maincpu->set_addrmap(AS_IO, &qx10_state::qx10_io);
-	m_maincpu->set_irq_acknowledge_callback("pic8259_master", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259_master", FUNC(pic8259_device::inta_call));
 
 	/* video hardware */
 	SCREEN(config, m_screen, SCREEN_TYPE_RASTER);

src/mame/drivers/sm7238.cpp

@@ -357,7 +357,7 @@ void sm7238_state::sm7238(machine_config &config)
 	I8080(config, m_maincpu, 16.5888_MHz_XTAL/9);
 	m_maincpu->set_addrmap(AS_PROGRAM, &sm7238_state::sm7238_mem);
 	m_maincpu->set_addrmap(AS_IO, &sm7238_state::sm7238_io);
-	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_call));
 
 	ADDRESS_MAP_BANK(config, "videobank").set_map(&sm7238_state::videobank_map).set_options(ENDIANNESS_LITTLE, 8, 32, 0x2000);
 

src/mame/drivers/tdv2324.cpp

@@ -270,6 +270,7 @@ void tdv2324_state::tdv2324(machine_config &config)
 	I8085A(config, m_maincpu, 8700000/2); // ???
 	m_maincpu->set_addrmap(AS_PROGRAM, &tdv2324_state::tdv2324_mem);
 	m_maincpu->set_addrmap(AS_IO, &tdv2324_state::tdv2324_io);
+	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_call));
 
 	I8085A(config, m_subcpu, 8000000/2); // ???
 	m_subcpu->set_addrmap(AS_PROGRAM, &tdv2324_state::tdv2324_sub_mem);

src/mame/drivers/vta2000.cpp

@@ -186,7 +186,7 @@ void vta2000_state::vta2000(machine_config &config)
 	I8080(config, m_maincpu, XTAL(4'000'000) / 4);
 	m_maincpu->set_addrmap(AS_PROGRAM, &vta2000_state::mem_map);
 	m_maincpu->set_addrmap(AS_IO, &vta2000_state::io_map);
-	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_cb));
+	m_maincpu->set_irq_acknowledge_callback("pic", FUNC(pic8259_device::inta_call));
 
 	PIT8253(config, m_mainpit, 0);
 	m_mainpit->set_clk<0>(500'000);