diff --git a/src/mess/drivers/geneve.c b/src/mess/drivers/geneve.c
index 74256bde3dc..5b9b5fcf17a 100644
--- a/src/mess/drivers/geneve.c
+++ b/src/mess/drivers/geneve.c
@@ -770,7 +770,7 @@ static MACHINE_CONFIG_START( geneve_60hz, geneve_state )
 	MCFG_DEVICE_ADD( GKEYBOARD_TAG, GENEVE_KEYBOARD, 0 )
 	MCFG_GENEVE_KBINT_HANDLER( WRITELINE(geneve_state, keyboard_interrupt) )
 	MCFG_GENEVE_MOUSE_ADD( GMOUSE_TAG )
-	MCFG_GENEVE_JOYPORT_ADD( JOYPORT_TAG, 60 )
+	MCFG_GENEVE_JOYPORT_ADD( JOYPORT_TAG )
 
 MACHINE_CONFIG_END
 
diff --git a/src/mess/drivers/ti99_4p.c b/src/mess/drivers/ti99_4p.c
index 301a8fa7030..912cb63b577 100644
--- a/src/mess/drivers/ti99_4p.c
+++ b/src/mess/drivers/ti99_4p.c
@@ -905,7 +905,7 @@ static MACHINE_CONFIG_START( ti99_4p_60hz, ti99_4p_state )
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "cass_out", 0.25)
 
 	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 60 )
+	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG )
 
 MACHINE_CONFIG_END
 
diff --git a/src/mess/drivers/ti99_4x.c b/src/mess/drivers/ti99_4x.c
index 9ca3fe65877..cc9cb008a24 100644
--- a/src/mess/drivers/ti99_4x.c
+++ b/src/mess/drivers/ti99_4x.c
@@ -99,13 +99,12 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( console_ready_cart );
 	DECLARE_WRITE_LINE_MEMBER( console_ready_grom );
 	DECLARE_WRITE_LINE_MEMBER( console_reset );
-	DECLARE_WRITE_LINE_MEMBER( extint );
 	DECLARE_WRITE_LINE_MEMBER( notconnected );
 
 	// Connections with the system interface chip 9901
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT2 );
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT12 );
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT2_from_v9938);
+	DECLARE_WRITE_LINE_MEMBER( extint );
+	DECLARE_WRITE_LINE_MEMBER( video_interrupt_in );
+	DECLARE_WRITE_LINE_MEMBER( handset_interrupt_in );
 
 	// Connections with the system interface TMS9901
 	DECLARE_READ8_MEMBER(read_by_9901);
@@ -135,7 +134,7 @@ private:
 	void    console_ready_join(int id, int state);
 
 	// Console type
-	int     m_console;
+	int     m_model;
 
 	// Latch for 9901 INT1, INT2, and INT12 lines
 	line_state  m_int1;
@@ -384,7 +383,7 @@ READ8_MEMBER( ti99_4x_state::cruread )
 	// Also, we translate the bit addresses to base addresses
 
 	// The QI version does not propagate the CRU signals to the cartridge slot
-	if (m_console != MODEL_4QI) m_gromport->crureadz(space, offset<<4, &value);
+	if (m_model != MODEL_4QI) m_gromport->crureadz(space, offset<<4, &value);
 	m_peribox->crureadz(space, offset<<4, &value);
 
 	return value;
@@ -394,7 +393,7 @@ WRITE8_MEMBER( ti99_4x_state::cruwrite )
 {
 	if (TRACE_CRU) logerror("ti99_4x: write access to CRU address %04x\n", offset << 1);
 	// The QI version does not propagate the CRU signals to the cartridge slot
-	if (m_console != MODEL_4QI) m_gromport->cruwrite(space, offset<<1, data);
+	if (m_model != MODEL_4QI) m_gromport->cruwrite(space, offset<<1, data);
 	m_peribox->cruwrite(space, offset<<1, data);
 }
 
@@ -452,7 +451,7 @@ READ8_MEMBER( ti99_4x_state::read_by_9901 )
 		//
 		// |K|K|K|K|K|I2|I1|C|
 		//
-		if (m_keyboard_column >= (m_console==MODEL_4? 5:6)) // joy 1, 2, handset
+		if (m_keyboard_column >= (m_model==MODEL_4? 5:6)) // joy 1, 2, handset
 		{
 			answer = m_joyport->read_port();
 			// The hardware bug of the TI-99/4A: you have to release the
@@ -463,7 +462,7 @@ READ8_MEMBER( ti99_4x_state::read_by_9901 )
 			// the line enough to make the TMS9901 sense the low level.
 			// A reported, feasible fix was to cut the line and insert a diode
 			// below the Alphalock key.
-			if ((ioport("ALPHABUG")!=0) && (m_console!=MODEL_4)) answer |= ioport("ALPHA")->read();
+			if ((ioport("ALPHABUG")!=0) && (m_model!=MODEL_4)) answer |= ioport("ALPHA")->read();
 		}
 		else
 		{
@@ -481,10 +480,10 @@ READ8_MEMBER( ti99_4x_state::read_by_9901 )
 
 	case TMS9901_INT8_INT15:
 		// |1|1|1|INT12|0|K|K|K|
-		if (m_keyboard_column >= (m_console==MODEL_4? 5:6)) answer = 0x07;
+		if (m_keyboard_column >= (m_model==MODEL_4? 5:6)) answer = 0x07;
 		else answer = ((ioport(column[m_keyboard_column])->read())>>5) & 0x07;
 		answer |= 0xe0;
-		if (m_console != MODEL_4 || m_int12==CLEAR_LINE) answer |= 0x10;
+		if (m_model != MODEL_4 || m_int12==CLEAR_LINE) answer |= 0x10;
 		break;
 
 	case TMS9901_P0_P7:
@@ -530,9 +529,9 @@ void ti99_4x_state::set_keyboard_column(int number, int data)
 	else
 		m_keyboard_column &= ~ (1 << number);
 
-	if (m_keyboard_column >= (m_console==MODEL_4? 5:6))
+	if (m_keyboard_column >= (m_model==MODEL_4? 5:6))
 	{
-		m_joyport->write_port(m_keyboard_column - (m_console==MODEL_4? 5:6) + 1);
+		m_joyport->write_port(m_keyboard_column - (m_model==MODEL_4? 5:6) + 1);
 	}
 
 	// TI-99/4:  joystick 1 = column 5
@@ -640,16 +639,13 @@ WRITE_LINE_MEMBER( ti99_4x_state::dbin_line )
 /*
     set the state of TMS9901's INT2 (called by the tms9928 core)
 */
-WRITE_LINE_MEMBER( ti99_4x_state::set_tms9901_INT2 )
+WRITE_LINE_MEMBER( ti99_4x_state::video_interrupt_in )
 {
 	if (TRACE_INTERRUPTS) logerror("ti99_4x: VDP INT2 on tms9901, level=%d\n", state);
-	m_int2 = (line_state)state;
-	m_tms9901->set_single_int(2, state);
-}
 
-WRITE_LINE_MEMBER(ti99_4x_state::set_tms9901_INT2_from_v9938)
-{
-	if (TRACE_INTERRUPTS) logerror("ti99_4x: VDP INT2 on tms9901, level=%d\n", state);
+	// Pulse for the handset
+	if (m_model == MODEL_4) m_joyport->pulse_clock();
+
 	m_int2 = (line_state)state;
 	m_tms9901->set_single_int(2, state);
 }
@@ -657,7 +653,7 @@ WRITE_LINE_MEMBER(ti99_4x_state::set_tms9901_INT2_from_v9938)
 /*
     set the state of TMS9901's INT12 (called by the handset prototype of TI-99/4)
 */
-WRITE_LINE_MEMBER( ti99_4x_state::set_tms9901_INT12)
+WRITE_LINE_MEMBER( ti99_4x_state::handset_interrupt_in)
 {
 	if (TRACE_INTERRUPTS) logerror("ti99_4x: joyport INT12 on tms9901, level=%d\n", state);
 	m_int12 = (line_state)state;
@@ -746,7 +742,7 @@ WRITE_LINE_MEMBER( ti99_4x_state::extint )
 {
 	if (TRACE_INTERRUPTS) logerror("ti99_4x: EXTINT level = %02x\n", state);
 	m_int1 = (line_state)state;
-	m_tms9901->set_single_int(11, state);
+	m_tms9901->set_single_int(1, state);
 }
 
 WRITE_LINE_MEMBER( ti99_4x_state::notconnected )
@@ -759,7 +755,7 @@ WRITE_LINE_MEMBER( ti99_4x_state::notconnected )
 static TMS9928A_INTERFACE(ti99_4_tms9928a_interface)
 {
 	0x4000,
-	DEVCB_DRIVER_LINE_MEMBER(ti99_4x_state, set_tms9901_INT2)
+	DEVCB_DRIVER_LINE_MEMBER(ti99_4x_state, video_interrupt_in)
 };
 
 /*
@@ -815,7 +811,7 @@ MACHINE_START_MEMBER(ti99_4x_state,ti99_4)
 	m_peribox->senila(CLEAR_LINE);
 	m_peribox->senilb(CLEAR_LINE);
 	m_nready_combined = 0;
-	m_console = MODEL_4;
+	m_model = MODEL_4;
 }
 
 MACHINE_RESET_MEMBER(ti99_4x_state,ti99_4)
@@ -889,6 +885,10 @@ static MACHINE_CONFIG_START( ti99_4, ti99_4x_state )
 	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_4x_state, console_ready_grom))
 	MCFG_GROM_ADD( GROM2_TAG, grom2_config )
 	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_4x_state, console_ready_grom))
+
+	// Joystick port
+	MCFG_TI_JOYPORT4_ADD( JOYPORT_TAG )
+	MCFG_JOYPORT_INT_HANDLER( WRITELINE(ti99_4x_state, handset_interrupt_in) )
 MACHINE_CONFIG_END
 
 /*
@@ -896,10 +896,6 @@ MACHINE_CONFIG_END
 */
 static MACHINE_CONFIG_DERIVED( ti99_4_60hz, ti99_4 )
 	MCFG_TI_TMS991x_ADD_NTSC(VIDEO_SYSTEM_TAG, TMS9918, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4_ADD( JOYPORT_TAG, 60 )
-	MCFG_JOYPORT_INT_HANDLER( WRITELINE(ti99_4x_state, set_tms9901_INT12) )
 MACHINE_CONFIG_END
 
 /*
@@ -907,10 +903,6 @@ MACHINE_CONFIG_END
 */
 static MACHINE_CONFIG_DERIVED( ti99_4_50hz, ti99_4 )
 	MCFG_TI_TMS991x_ADD_PAL(VIDEO_SYSTEM_TAG, TMS9929, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4_ADD( JOYPORT_TAG, 50 )
-	MCFG_JOYPORT_INT_HANDLER( WRITELINE(ti99_4x_state, set_tms9901_INT12) )
 MACHINE_CONFIG_END
 
 /**********************************************************************
@@ -922,7 +914,7 @@ MACHINE_START_MEMBER(ti99_4x_state,ti99_4a)
 	m_peribox->senila(CLEAR_LINE);
 	m_peribox->senilb(CLEAR_LINE);
 	m_nready_combined = 0;
-	m_console = MODEL_4A;
+	m_model = MODEL_4A;
 }
 
 MACHINE_RESET_MEMBER(ti99_4x_state,ti99_4a)
@@ -992,28 +984,23 @@ static MACHINE_CONFIG_START( ti99_4a, ti99_4x_state )
 	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_4x_state, console_ready_grom))
 	MCFG_GROM_ADD( GROM2_TAG, grom2_config )
 	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_4x_state, console_ready_grom))
+
+	// Joystick port
+	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG )
 MACHINE_CONFIG_END
 
 /*
     US version: 60 Hz, NTSC
 */
 static MACHINE_CONFIG_DERIVED( ti99_4a_60hz, ti99_4a )
-	// Video hardware
 	MCFG_TI_TMS991x_ADD_NTSC(VIDEO_SYSTEM_TAG, TMS9918A, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 60 )
 MACHINE_CONFIG_END
 
 /*
     European version: 50 Hz, PAL
 */
 static MACHINE_CONFIG_DERIVED( ti99_4a_50hz, ti99_4a )
-	// Video hardware
 	MCFG_TI_TMS991x_ADD_PAL(VIDEO_SYSTEM_TAG, TMS9929A, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 50 )
 MACHINE_CONFIG_END
 
 /************************************************************************
@@ -1029,7 +1016,7 @@ MACHINE_START_MEMBER(ti99_4x_state, ti99_4qi)
 {
 	m_peribox->senila(CLEAR_LINE);
 	m_peribox->senilb(CLEAR_LINE);
-	m_console = MODEL_4QI;
+	m_model = MODEL_4QI;
 	m_nready_combined = 0;
 }
 
@@ -1041,22 +1028,14 @@ MACHINE_CONFIG_END
     US version: 60 Hz, NTSC
 */
 static MACHINE_CONFIG_DERIVED( ti99_4qi_60hz, ti99_4qi )
-	/* Video hardware */
 	MCFG_TI_TMS991x_ADD_NTSC(VIDEO_SYSTEM_TAG, TMS9918A, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 60 )
 MACHINE_CONFIG_END
 
 /*
     European version: 50 Hz, PAL
 */
 static MACHINE_CONFIG_DERIVED( ti99_4qi_50hz, ti99_4qi )
-	// Video hardware
 	MCFG_TI_TMS991x_ADD_PAL(VIDEO_SYSTEM_TAG, TMS9929A, ti99_4_tms9928a_interface)
-
-	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 50 )
 MACHINE_CONFIG_END
 
 /************************************************************************
@@ -1085,7 +1064,7 @@ static MACHINE_CONFIG_START( ti99_4ev_60hz, ti99_4x_state )
 	// interlace mode, but in non-interlace modes only half of the lines are
 	// painted. Accordingly, the full set of lines is refreshed at 30 Hz,
 	// not 60 Hz. This should be fixed in the v9938 emulation.
-	MCFG_TI_V9938_ADD(VIDEO_SYSTEM_TAG, 30, SCREEN_TAG, 2500, 512+32, (212+28)*2, ti99_4x_state, set_tms9901_INT2_from_v9938)
+	MCFG_TI_V9938_ADD(VIDEO_SYSTEM_TAG, 30, SCREEN_TAG, 2500, 512+32, (212+28)*2, ti99_4x_state, video_interrupt_in)
 	MCFG_TIMER_DRIVER_ADD_SCANLINE("scantimer", ti99_4x_state, ti99_4ev_hblank_interrupt, SCREEN_TAG, 0, 1)
 
 	/* Main board */
@@ -1137,7 +1116,7 @@ static MACHINE_CONFIG_START( ti99_4ev_60hz, ti99_4x_state )
 	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_4x_state, console_ready_grom))
 
 	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 60 )
+	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG )
 
 MACHINE_CONFIG_END
 
diff --git a/src/mess/drivers/ti99_8.c b/src/mess/drivers/ti99_8.c
index 4f2c60fd988..ea817f548d2 100644
--- a/src/mess/drivers/ti99_8.c
+++ b/src/mess/drivers/ti99_8.c
@@ -218,7 +218,6 @@ Known Issues (MZ, 2010-11-07)
 #define TRACE_READY 0
 #define TRACE_INTERRUPTS 0
 #define TRACE_CRU 0
-#define LOG logerror
 
 /*
     READY bits.
@@ -265,14 +264,11 @@ public:
 	DECLARE_WRITE_LINE_MEMBER( console_ready_grom );
 	DECLARE_WRITE_LINE_MEMBER( console_ready_speech );
 	DECLARE_WRITE_LINE_MEMBER( console_reset );
-	DECLARE_WRITE_LINE_MEMBER( extint );
 	DECLARE_WRITE_LINE_MEMBER( notconnected );
 
 	// Connections with the system interface chip 9901
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT2 );
-
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT12 );
-	DECLARE_WRITE_LINE_MEMBER( set_tms9901_INT2_from_v9938);
+	DECLARE_WRITE_LINE_MEMBER( extint );
+	DECLARE_WRITE_LINE_MEMBER( video_interrupt );
 
 	// Connections with the system interface TMS9901
 	DECLARE_READ8_MEMBER(read_by_9901);
@@ -298,8 +294,8 @@ private:
 	void    console_ready_join(int id, int state);
 
 	// Latch for 9901 INT2, INT1 lines
-	int     m_9901_int;
-	void    set_9901_int(int line, line_state state);
+	line_state  m_int1;
+	line_state  m_int2;
 
 	// Connected devices
 	required_device<tms9995_device>     m_cpu;
@@ -523,7 +519,7 @@ GROM_LIBRARY_CONFIG3(pascal3, region_gromlib3)
 
 READ8_MEMBER( ti99_8_state::cruread )
 {
-//  if (VERBOSE>6) LOG("read access to CRU address %04x\n", offset << 4);
+//  if (VERBOSE>6) logerror("read access to CRU address %04x\n", offset << 4);
 	UINT8 value = 0;
 
 	// Similar to the bus8z_devices, just let the mapper, the gromport, and the p-box
@@ -533,13 +529,13 @@ READ8_MEMBER( ti99_8_state::cruread )
 	m_gromport->crureadz(space, offset<<4, &value);
 	m_peribox->crureadz(space, offset<<4, &value);
 
-	if (TRACE_CRU) LOG("ti99_8: CRU %04x -> %02x\n", offset<<4, value);
+	if (TRACE_CRU) logerror("ti99_8: CRU %04x -> %02x\n", offset<<4, value);
 	return value;
 }
 
 WRITE8_MEMBER( ti99_8_state::cruwrite )
 {
-	if (TRACE_CRU) LOG("ti99_8: CRU %04x <- %x\n", offset<<1, data);
+	if (TRACE_CRU) logerror("ti99_8: CRU %04x <- %x\n", offset<<1, data);
 	m_mainboard->cruwrite(space, offset<<1, data);
 	m_gromport->cruwrite(space, offset<<1, data);
 	m_peribox->cruwrite(space, offset<<1, data);
@@ -584,7 +580,9 @@ READ8_MEMBER( ti99_8_state::read_by_9901 )
 		{
 			answer = ioport(column[m_keyboard_column])->read();
 		}
-		answer = (answer << 6) | m_9901_int;
+		answer = (answer << 6);
+		if (m_int1 == CLEAR_LINE) answer |= 0x02;
+		if (m_int2 == CLEAR_LINE) answer |= 0x04;
 
 		break;
 
@@ -632,8 +630,10 @@ READ8_MEMBER( ti99_8_state::read_by_9901 )
 */
 void ti99_8_state::set_keyboard_column(int number, int data)
 {
-	if (data != 0)      m_keyboard_column |= 1 << number;
-	else                m_keyboard_column &= ~(1 << number);
+	if (data != 0)
+		m_keyboard_column |= 1 << number;
+	else
+		m_keyboard_column &= ~(1 << number);
 
 	if (m_keyboard_column >= 14)
 	{
@@ -667,6 +667,9 @@ WRITE_LINE_MEMBER( ti99_8_state::keyC3 )
 WRITE_LINE_MEMBER( ti99_8_state::CRUS )
 {
 	m_mainboard->CRUS_set(state==ASSERT_LINE);
+
+	// In Armadillo mode, GROMs are located at f830; accordingly, the
+	// gromport must be reconfigured
 	if (state==ASSERT_LINE)
 	{
 		m_gromport->set_grom_base(0x9800, 0xfbf1);
@@ -718,55 +721,16 @@ WRITE8_MEMBER( ti99_8_state::tms9901_interrupt )
 	m_cpu->set_input_line(INT_9995_INT1, data);
 }
 
-/*
-const tms9901_interface tms9901_wiring_ti99_8 =
-{
-    TMS9901_INT1 | TMS9901_INT2 | TMS9901_INTC,
-
-    // read handler
-    DEVCB_DRIVER_MEMBER(ti99_8_state, read_by_9901),
-
-    // write handlers
-    {
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, keyC0),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, keyC1),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, keyC2),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, keyC3),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, CRUS),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, PTGEN),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, cassette_motor),
-        DEVCB_NULL,
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, audio_gate),
-        DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, cassette_output),
-        DEVCB_NULL,
-        DEVCB_NULL,
-        DEVCB_NULL,
-        DEVCB_NULL,
-        DEVCB_NULL,
-        DEVCB_NULL
-    },
-
-    DEVCB_DRIVER_MEMBER(ti99_8_state, tms9901_interrupt)
-};
-*/
-
 /*****************************************************************************/
 
-void ti99_8_state::set_9901_int( int line, line_state state)
-{
-	m_tms9901->set_single_int(line, state);
-	// We latch the value for the read operation. Mind the negative logic.
-	if (state==CLEAR_LINE) m_9901_int |= (1<<line);
-	else m_9901_int &= ~(1<<line);
-}
-
 /*
     set the state of TMS9901's INT2 (called by the tms9928 core)
 */
-WRITE_LINE_MEMBER( ti99_8_state::set_tms9901_INT2 )
+WRITE_LINE_MEMBER( ti99_8_state::video_interrupt )
 {
-	if (TRACE_INTERRUPTS) LOG("ti99_8: VDP int 2 on tms9901, level=%02x\n", state);
-	set_9901_int(2, (line_state)state);
+	if (TRACE_INTERRUPTS) logerror("ti99_8: VDP int 2 on tms9901, level=%02x\n", state);
+	m_int2 = (line_state)state;
+	m_tms9901->set_single_int(2, state);
 }
 
 /***********************************************************
@@ -787,7 +751,7 @@ void ti99_8_state::console_ready_join(int id, int state)
 
 	if (TRACE_READY)
 	{
-		if (m_nready_prev != m_nready_combined) LOG("ti99_8: READY bits = %04x\n", ~m_nready_combined);
+		if (m_nready_prev != m_nready_combined) logerror("ti99_8: READY bits = %04x\n", ~m_nready_combined);
 	}
 
 	m_nready_prev = m_nready_combined;
@@ -842,19 +806,20 @@ WRITE_LINE_MEMBER( ti99_8_state::console_reset )
 
 WRITE_LINE_MEMBER( ti99_8_state::extint )
 {
-	if (TRACE_READY) LOG("ti99_8: EXTINT level = %02x\n", state);
-	set_9901_int(1, (line_state)state);
+	if (TRACE_READY) logerror("ti99_8: EXTINT level = %02x\n", state);
+	m_int1 = (line_state)state;
+	m_tms9901->set_single_int(1, state);
 }
 
 WRITE_LINE_MEMBER( ti99_8_state::notconnected )
 {
-	if (TRACE_READY) LOG("ti99_8: Setting a not connected line ... ignored\n");
+	if (TRACE_READY) logerror("ti99_8: Setting a not connected line ... ignored\n");
 }
 
 static TMS9928A_INTERFACE(ti99_8_tms9118a_interface)
 {
 	0x4000,
-	DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, set_tms9901_INT2)
+	DEVCB_DRIVER_LINE_MEMBER(ti99_8_state, video_interrupt)
 };
 
 WRITE8_MEMBER( ti99_8_state::external_operation )
@@ -863,7 +828,7 @@ WRITE8_MEMBER( ti99_8_state::external_operation )
 	if (offset == IDLE_OP) return;
 	else
 	{
-		LOG("ti99_4x: External operation %s not implemented on TI-99/8 board\n", extop[offset]);
+		logerror("ti99_4x: External operation %s not implemented on TI-99/8 board\n", extop[offset]);
 	}
 }
 
@@ -1002,11 +967,12 @@ MACHINE_RESET_MEMBER(ti99_8_state, ti99_8)
 	m_nready_combined = 0;
 	m_gromport->set_grom_base(0x9800, 0xfff1);
 
-	// Clear INT1 and INT2 latch (negative logic)
-	m_9901_int = 0x03;
+	// Clear INT1 and INT2 latch
+	m_int1 = CLEAR_LINE;
+	m_int2 = CLEAR_LINE;
 }
 
-static MACHINE_CONFIG_START( ti99_8_60hz, ti99_8_state )
+static MACHINE_CONFIG_START( ti99_8, ti99_8_state )
 	// basic machine hardware */
 	// TMS9995-MP9537 CPU @ 10.7 MHz
 	// MP9537 mask: This variant of the TMS9995 does not contain on-chip RAM
@@ -1017,9 +983,6 @@ static MACHINE_CONFIG_START( ti99_8_60hz, ti99_8_state )
 	MCFG_MACHINE_START_OVERRIDE(ti99_8_state, ti99_8 )
 	MCFG_MACHINE_RESET_OVERRIDE(ti99_8_state, ti99_8 )
 
-	/* Video hardware */
-	MCFG_TI998_ADD_NTSC(VIDEO_SYSTEM_TAG, TMS9118, ti99_8_tms9118a_interface)
-
 	/* Main board */
 	MCFG_DEVICE_ADD(TMS9901_TAG, TMS9901, XTAL_10_738635MHz/4.0)
 	MCFG_TMS9901_READBLOCK_HANDLER( READ8(ti99_8_state, read_by_9901) )
@@ -1074,77 +1037,21 @@ static MACHINE_CONFIG_START( ti99_8_60hz, ti99_8_state )
 	MCFG_SPEECH8_READY_CALLBACK(WRITELINE(ti99_8_state, console_ready_speech))
 
 	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 60 )
+	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG )
 MACHINE_CONFIG_END
 
+/*
+    TI-99/8 US version (NTSC, 60 Hz)
+*/
+static MACHINE_CONFIG_DERIVED( ti99_8_60hz, ti99_8 )
+	MCFG_TI998_ADD_NTSC(VIDEO_SYSTEM_TAG, TMS9118, ti99_8_tms9118a_interface)
+MACHINE_CONFIG_END
 
-static MACHINE_CONFIG_START( ti99_8_50hz, ti99_8_state )
-	/* basic machine hardware */
-	/* TMS9995-MP9537 CPU @ 10.7 MHz */
-	MCFG_TMS99xx_ADD("maincpu", TMS9995_MP9537, XTAL_10_738635MHz, memmap, crumap)
-	MCFG_TMS9995_EXTOP_HANDLER( WRITE8(ti99_8_state, external_operation) )
-	MCFG_TMS9995_CLKOUT_HANDLER( WRITELINE(ti99_8_state, clock_out) )
-
-	MCFG_MACHINE_START_OVERRIDE(ti99_8_state, ti99_8 )
-	MCFG_MACHINE_RESET_OVERRIDE(ti99_8_state, ti99_8 )
-
-	/* Video hardware */
+/*
+    TI-99/8 European version (PAL, 50 Hz)
+*/
+static MACHINE_CONFIG_DERIVED( ti99_8_50hz, ti99_8 )
 	MCFG_TI998_ADD_PAL(VIDEO_SYSTEM_TAG, TMS9129, ti99_8_tms9118a_interface)
-
-	/* Main board */
-	MCFG_DEVICE_ADD(TMS9901_TAG, TMS9901, XTAL_10_738635MHz/4.0)
-	MCFG_TMS9901_READBLOCK_HANDLER( READ8(ti99_8_state, read_by_9901) )
-	MCFG_TMS9901_P0_HANDLER( WRITELINE( ti99_8_state, keyC0) )
-	MCFG_TMS9901_P1_HANDLER( WRITELINE( ti99_8_state, keyC1) )
-	MCFG_TMS9901_P2_HANDLER( WRITELINE( ti99_8_state, keyC2) )
-	MCFG_TMS9901_P3_HANDLER( WRITELINE( ti99_8_state, keyC3) )
-	MCFG_TMS9901_P4_HANDLER( WRITELINE( ti99_8_state, CRUS) )
-	MCFG_TMS9901_P5_HANDLER( WRITELINE( ti99_8_state, PTGEN) )
-	MCFG_TMS9901_P6_HANDLER( WRITELINE( ti99_8_state, cassette_motor) )
-	MCFG_TMS9901_P8_HANDLER( WRITELINE( ti99_8_state, audio_gate) )
-	MCFG_TMS9901_P9_HANDLER( WRITELINE( ti99_8_state, cassette_output) )
-	MCFG_TMS9901_INTLEVEL_HANDLER( WRITE8( ti99_8_state, tms9901_interrupt) )
-
-	MCFG_MAINBOARD8_ADD( MAINBOARD8_TAG, mapper_conf )
-	MCFG_TI99_GROMPORT_ADD( GROMPORT_TAG )
-	MCFG_GROMPORT_READY_HANDLER( WRITELINE(ti99_8_state, console_ready_cart) )
-	MCFG_GROMPORT_RESET_HANDLER( WRITELINE(ti99_8_state, console_reset) )
-
-	/* Peripheral expansion box */
-	MCFG_DEVICE_ADD( PERIBOX_TAG, PERIBOX_998, 0)
-	MCFG_PERIBOX_INTA_HANDLER( WRITELINE(ti99_8_state, extint) )
-	MCFG_PERIBOX_INTB_HANDLER( WRITELINE(ti99_8_state, notconnected) )
-	MCFG_PERIBOX_READY_HANDLER( WRITELINE(ti99_8_state, console_ready_pbox) )
-
-	/* Sound hardware */
-	MCFG_TI_SOUND_76496_ADD( TISOUND_TAG )
-	MCFG_TI_SOUND_READY_HANDLER( WRITELINE(ti99_8_state, console_ready_sound) )
-
-	/* Cassette drives */
-	MCFG_SPEAKER_STANDARD_MONO("cass_out")
-	MCFG_CASSETTE_ADD( "cassette", default_cassette_interface )
-	MCFG_SOUND_WAVE_ADD(WAVE_TAG, "cassette")
-	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "cass_out", 0.25)
-
-	/* Console GROMs */
-	MCFG_GROM_ADD( GROM0_TAG, grom0_config )
-	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_8_state, console_ready_grom))
-	MCFG_GROM_ADD( GROM1_TAG, grom1_config )
-	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_8_state, console_ready_grom))
-	MCFG_GROM_ADD( GROM2_TAG, grom2_config )
-	MCFG_GROM_READY_CALLBACK(WRITELINE(ti99_8_state, console_ready_grom))
-
-	/* Pascal GROM libraries. */
-	MCFG_GROM_LIBRARY_ADD8(pascal1_grom, pascal1)
-	MCFG_GROM_LIBRARY_ADD8(pascal2_grom, pascal2)
-	MCFG_GROM_LIBRARY_ADD3(pascal3_grom, pascal3)
-
-	/* Devices */
-	MCFG_DEVICE_ADD(SPEECH_TAG, TI99_SPEECH8, 0)
-	MCFG_SPEECH8_READY_CALLBACK(WRITELINE(ti99_8_state, console_ready_speech))
-
-	// Joystick port
-	MCFG_TI_JOYPORT4A_ADD( JOYPORT_TAG, 50 )
 MACHINE_CONFIG_END
 
 /*
diff --git a/src/mess/machine/ti99/handset.c b/src/mess/machine/ti99/handset.c
index 7ee64a47015..cb8ae039b21 100644
--- a/src/mess/machine/ti99/handset.c
+++ b/src/mess/machine/ti99/handset.c
@@ -87,34 +87,26 @@ void ti99_handset_device::write_dev(UINT8 data)
 */
 void ti99_handset_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
 {
-	if (id==DELAY_TIMER)
+	m_clock_high = !m_clock_high;
+	m_buf >>= 4;
+	m_buflen--;
+
+	// Clear the INT12 line
+	m_joyport->set_interrupt(CLEAR_LINE);
+
+	if (m_buflen == 1)
 	{
-		m_clock_high = !m_clock_high;
-		m_buf >>= 4;
-		m_buflen--;
-
-		// Clear the INT12 line
-		m_joyport->set_interrupt(CLEAR_LINE);
-
-		if (m_buflen == 1)
-		{
-			// Unless I am missing something, the third and last nibble of the
-			// message is not acknowledged by the DSR in any way, and the first nibble
-			// of next message is not requested for either, so we need to decide on
-			// our own when we can post a new event.  Currently, we wait for 1000us
-			// after the DSR acknowledges the second nybble.
-			m_delay_timer->adjust(attotime::from_usec(1000));
-		}
-
-		if (m_buflen == 0)
-			/* See if we need to post a new event */
-			do_task();
-	}
-	else
-	{
-		// Poll timer
-		do_task();
+		// Unless I am missing something, the third and last nibble of the
+		// message is not acknowledged by the DSR in any way, and the first nibble
+		// of next message is not requested for either, so we need to decide on
+		// our own when we can post a new event.  Currently, we wait for 1000us
+		// after the DSR acknowledges the second nybble.
+		m_delay_timer->adjust(attotime::from_usec(1000));
 	}
+
+	if (m_buflen == 0)
+		/* See if we need to post a new event */
+	do_task();
 }
 
 /*
@@ -318,18 +310,21 @@ void ti99_handset_device::do_task()
 	}
 }
 
+void ti99_handset_device::pulse_clock()
+{
+	logerror("handset: pulse_clock\n");
+	do_task();
+}
+
 void ti99_handset_device::device_start(void)
 {
 	m_delay_timer = timer_alloc(DELAY_TIMER);
-	m_poll_timer = timer_alloc(POLL_TIMER);
-	m_poll_timer->adjust(attotime::from_hz(m_joyport->clock()), 0, attotime::from_hz(m_joyport->clock()));
 }
 
 void ti99_handset_device::device_reset(void)
 {
 	if (VERBOSE>5) LOG("ti99_handset_device: Reset\n");
 	m_delay_timer->enable(true);
-	m_poll_timer->enable(true);
 	m_buf = 0;
 	m_buflen = 0;
 	m_clock_high = false;
diff --git a/src/mess/machine/ti99/handset.h b/src/mess/machine/ti99/handset.h
index 4e1bd4f44ad..c7f13c8cbb8 100644
--- a/src/mess/machine/ti99/handset.h
+++ b/src/mess/machine/ti99/handset.h
@@ -32,6 +32,8 @@ public:
 	UINT8 read_dev();
 	void  write_dev(UINT8 data);
 
+	void pulse_clock();
+
 protected:
 	virtual void device_start(void);
 	virtual void device_reset(void);
@@ -54,7 +56,6 @@ private:
 	UINT8   previous_key[MAX_HANDSETS];
 
 	emu_timer *m_delay_timer;
-	emu_timer *m_poll_timer;
 };
 
 #define MCFG_HANDSET_ADD(_tag, _intf, _clock )  \
diff --git a/src/mess/machine/ti99/joyport.c b/src/mess/machine/ti99/joyport.c
index 8099964b925..d54f270d978 100644
--- a/src/mess/machine/ti99/joyport.c
+++ b/src/mess/machine/ti99/joyport.c
@@ -63,6 +63,14 @@ void joyport_device::write_port(int data)
 	m_connected->write_dev(data);
 }
 
+/*
+    This is only used for the handset device of the TI-99/4. It is driven by the VDP interrupt.
+*/
+void joyport_device::pulse_clock()
+{
+	m_connected->pulse_clock();
+}
+
 /*
     Propagate the interrupt to the defined target. Only used for the handset
     at the prototype 99/4.
@@ -75,7 +83,6 @@ WRITE_LINE_MEMBER( joyport_device::set_interrupt )
 void joyport_device::device_start()
 {
 	m_interrupt.resolve();
-	logerror("joyport: Set clock to %d\n", m_clock);
 }
 
 void joyport_device::device_config_complete()
diff --git a/src/mess/machine/ti99/joyport.h b/src/mess/machine/ti99/joyport.h
index 51f25c19268..0faeb5536d7 100644
--- a/src/mess/machine/ti99/joyport.h
+++ b/src/mess/machine/ti99/joyport.h
@@ -31,18 +31,17 @@ class joyport_device;
 ********************************************************************/
 class joyport_attached_device : public device_t
 {
-	friend class joyport_device;
 public:
 	joyport_attached_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
 	: device_t(mconfig, type, name, tag, owner, clock, shortname, source) { }
 
+	virtual UINT8 read_dev() =0;
+	virtual void write_dev(UINT8 data) =0;
+	virtual void pulse_clock() { };
+
 protected:
 	virtual void device_config_complete();
 	joyport_device* m_joyport;
-
-private:
-	virtual UINT8 read_dev() =0;
-	virtual void write_dev(UINT8 data) =0;
 };
 
 /********************************************************************
@@ -55,6 +54,7 @@ public:
 	UINT8   read_port();
 	void    write_port(int data);
 	void    set_interrupt(int state);
+	void    pulse_clock();
 
 	template<class _Object> static devcb2_base &static_set_int_callback(device_t &device, _Object object) { return downcast<joyport_device &>(device).m_interrupt.set_callback(object); }
 
@@ -74,16 +74,16 @@ SLOT_INTERFACE_EXTERN(joystick_port_gen);
 #define MCFG_JOYPORT_INT_HANDLER( _intcallb ) \
 	devcb = &joyport_device::static_set_int_callback( *device, DEVCB2_##_intcallb );
 
-#define MCFG_GENEVE_JOYPORT_ADD( _tag, _clock )  \
-	MCFG_DEVICE_ADD(_tag, JOYPORT, _clock) \
+#define MCFG_GENEVE_JOYPORT_ADD( _tag )  \
+	MCFG_DEVICE_ADD(_tag, JOYPORT, 0) \
 	MCFG_DEVICE_SLOT_INTERFACE(joystick_port_gen, "twinjoy", false)
 
-#define MCFG_TI_JOYPORT4A_ADD( _tag, _clock )    \
-	MCFG_DEVICE_ADD(_tag, JOYPORT, _clock) \
+#define MCFG_TI_JOYPORT4A_ADD( _tag )    \
+	MCFG_DEVICE_ADD(_tag, JOYPORT, 0) \
 	MCFG_DEVICE_SLOT_INTERFACE(joystick_port, "twinjoy", false)
 
-#define MCFG_TI_JOYPORT4_ADD( _tag, _clock ) \
-	MCFG_DEVICE_ADD(_tag, JOYPORT, _clock) \
+#define MCFG_TI_JOYPORT4_ADD( _tag ) \
+	MCFG_DEVICE_ADD(_tag, JOYPORT, 0) \
 	MCFG_DEVICE_SLOT_INTERFACE(joystick_port_994, "twinjoy", false)
 
 #endif /* __JOYPORT__ */
diff --git a/src/mess/machine/ti99/mecmouse.c b/src/mess/machine/ti99/mecmouse.c
index 20b66a4eb9d..d6476276d6e 100644
--- a/src/mess/machine/ti99/mecmouse.c
+++ b/src/mess/machine/ti99/mecmouse.c
@@ -171,7 +171,10 @@ void mecmouse_device::device_timer(emu_timer &timer, device_timer_id id, int par
 void mecmouse_device::device_start(void)
 {
 	m_poll_timer = timer_alloc(POLL_TIMER);
-	m_poll_timer->adjust(attotime::from_hz(m_joyport->clock()), 0, attotime::from_hz(m_joyport->clock()));
+	// The poll time cannot depend on the console settings, since the TI-99/4A
+	// has no clock line on the joystick port. The rate is not mentioned in
+	// the specs; however, if it is too low, the mouse pointer will do jumps
+	m_poll_timer->adjust(attotime::from_hz(100), 0, attotime::from_hz(100));
 }
 
 void mecmouse_device::device_reset(void)