diff --git a/src/mame/drivers/wecleman.cpp b/src/mame/drivers/wecleman.cpp
index 09f16c90031..a76a3385ffc 100644
--- a/src/mame/drivers/wecleman.cpp
+++ b/src/mame/drivers/wecleman.cpp
@@ -276,6 +276,7 @@ TODO:
 #include "cpu/m68000/m68000.h"
 #include "cpu/m6809/m6809.h"
 #include "cpu/z80/z80.h"
+#include "machine/adc0804.h"
 #include "machine/gen_latch.h"
 #include "sound/ym2151.h"
 #include "speaker.h"
@@ -391,16 +392,16 @@ WRITE16_MEMBER(wecleman_state::selected_ip_w)
 }
 
 /* $140021.b - Return the previously selected input port's value */
-READ16_MEMBER(wecleman_state::selected_ip_r)
+uint8_t wecleman_state::selected_ip_r()
 {
 	switch ( (m_selected_ip >> 5) & 3 )
 	{                                                                   // From WEC Le Mans Schems:
 		case 0:  return ioport("ACCEL")->read();        // Accel - Schems: Accelevr
-		case 1:  return ~0;                                             // ????? - Schems: Not Used
+		case 1:  return 0;                                              // ????? - Schems: Not Used
 		case 2:  return ioport("STEER")->read();        // Wheel - Schems: Handlevr
-		case 3:  return ~0;                                             // Table - Schems: Turnvr
+		case 3:  return 0;                                              // Table - Schems: Turnvr
 
-		default: return ~0;
+		default: return 0;
 	}
 }
 
@@ -539,8 +540,7 @@ void wecleman_state::wecleman_map(address_map &map)
 	map(0x140012, 0x140013).portr("IN1");    // ??
 	map(0x140014, 0x140015).portr("DSWA");   // DSW 2
 	map(0x140016, 0x140017).portr("DSWB");   // DSW 1
-	map(0x140020, 0x140021).writeonly();   // Paired with writes to $140003
-	map(0x140020, 0x140021).r(FUNC(wecleman_state::selected_ip_r)); // Accelerator or Wheel or ..
+	map(0x140021, 0x140021).rw("adc", FUNC(adc0804_device::read), FUNC(adc0804_device::write));
 	map(0x140030, 0x140031).nopw();    // toggles between 0 & 1 on hitting bumps and crashes (vibration?)
 }
 
@@ -572,7 +572,7 @@ void wecleman_state::hotchase_map(address_map &map)
 	map(0x140012, 0x140013).portr("IN1");    // ?? bit 4 from sound cpu
 	map(0x140014, 0x140015).portr("DSW2");   // DSW 2
 	map(0x140016, 0x140017).portr("DSW1");   // DSW 1
-	map(0x140020, 0x140021).r(FUNC(wecleman_state::selected_ip_r)).nopw(); // Paired with writes to $140003
+	map(0x140021, 0x140021).rw("adc", FUNC(adc0804_device::read), FUNC(adc0804_device::write)); // Paired with writes to $140003
 	map(0x140022, 0x140023).nopr(); // read and written at $601c0, unknown purpose
 	map(0x140030, 0x140031).nopw();    // signal to cabinet vibration motors?
 }
@@ -764,7 +764,7 @@ static INPUT_PORTS_START( wecleman )
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_SERVICE2 ) PORT_NAME("Right SW")  // right sw
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_SERVICE3 ) PORT_NAME("Left SW")  // left sw
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_SERVICE4 ) PORT_NAME("Thermo SW")  // thermo
-	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_CUSTOM )   // from sound cpu ?
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_READ_LINE_DEVICE_MEMBER("adc", adc0804_device, intr_r)
 	PORT_BIT( 0xf0, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DSWA")  /* $140015.b */
@@ -861,7 +861,7 @@ static INPUT_PORTS_START( hotchase )
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_SERVICE2 ) PORT_NAME("Right SW")   // right sw
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_SERVICE3 ) PORT_NAME("Left SW")  // left sw
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_SERVICE4 ) PORT_NAME("Thermo SW")  // thermo
-	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_CUSTOM ) // from sound cpu
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_READ_LINE_DEVICE_MEMBER("adc", adc0804_device, intr_r)
 	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_READ_LINE_MEMBER(wecleman_state, hotchase_sound_status_r)
 	PORT_BIT( 0xe0, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
@@ -1068,6 +1068,9 @@ void wecleman_state::wecleman(machine_config &config)
 	MCFG_MACHINE_START_OVERRIDE(wecleman_state, wecleman)
 	MCFG_MACHINE_RESET_OVERRIDE(wecleman_state, wecleman)
 
+	adc0804_device &adc(ADC0804(config, "adc", 640000)); // unknown "ADCCLK" (generated on video board?)
+	adc.vin_callback().set(FUNC(wecleman_state::selected_ip_r));
+
 	/* video hardware */
 	SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
 	m_screen->set_refresh_hz(60);
@@ -1144,6 +1147,9 @@ void wecleman_state::hotchase(machine_config &config)
 	MCFG_MACHINE_RESET_OVERRIDE(wecleman_state, hotchase)
 	MCFG_MACHINE_START_OVERRIDE(wecleman_state, hotchase)
 
+	adc0804_device &adc(ADC0804(config, "adc", 640000)); // unknown clock (generated on video board?)
+	adc.vin_callback().set(FUNC(wecleman_state::selected_ip_r));
+
 	/* video hardware */
 	SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
 	m_screen->set_refresh_hz(60);
diff --git a/src/mame/includes/wecleman.h b/src/mame/includes/wecleman.h
index 6b9fb170249..75352e1c2ef 100644
--- a/src/mame/includes/wecleman.h
+++ b/src/mame/includes/wecleman.h
@@ -93,7 +93,7 @@ private:
 	DECLARE_WRITE16_MEMBER(wecleman_protection_w);
 	DECLARE_WRITE16_MEMBER(irqctrl_w);
 	DECLARE_WRITE16_MEMBER(selected_ip_w);
-	DECLARE_READ16_MEMBER(selected_ip_r);
+	uint8_t selected_ip_r();
 	DECLARE_WRITE16_MEMBER(blitter_w);
 	DECLARE_READ8_MEMBER(multiply_r);
 	DECLARE_WRITE8_MEMBER(multiply_w);