From 8f6dff4521bd1d2e1cf29b84b01172e165b6514a Mon Sep 17 00:00:00 2001
From: Lord-Nightmare <Lord-Nightmare@users.noreply.github.com>
Date: Wed, 24 Jun 2020 01:38:47 -0400
Subject: [PATCH] Switch all the pre-WPC Williams pinballs to using io port
 arrays for their switch matrix, which gets rid of runtime lookups and fixes
 MAME crashes if a value with more than one bit set is written to the column
 select. [Lord Nightmare]

---
 src/mame/drivers/s11.cpp  | 36 ++++++++++++++++++++--------------
 src/mame/drivers/s11a.cpp | 19 ++++++++----------
 src/mame/drivers/s11b.cpp | 19 ++++++++----------
 src/mame/drivers/s11c.cpp | 19 ++++++++----------
 src/mame/drivers/s3.cpp   | 38 +++++++++++++++++++++---------------
 src/mame/drivers/s4.cpp   | 38 +++++++++++++++++++++---------------
 src/mame/drivers/s6.cpp   | 38 +++++++++++++++++++++---------------
 src/mame/drivers/s6a.cpp  | 38 +++++++++++++++++++++---------------
 src/mame/drivers/s7.cpp   | 41 ++++++++++++++++++++++++---------------
 src/mame/drivers/s8.cpp   | 39 ++++++++++++++++++++++---------------
 src/mame/drivers/s8a.cpp  | 39 ++++++++++++++++++++++---------------
 src/mame/drivers/s9.cpp   | 39 ++++++++++++++++++++++---------------
 src/mame/includes/s11.h   |  4 +++-
 13 files changed, 230 insertions(+), 177 deletions(-)

diff --git a/src/mame/drivers/s11.cpp b/src/mame/drivers/s11.cpp
index 13e5e707ec2..0d5d7b7e1bb 100644
--- a/src/mame/drivers/s11.cpp
+++ b/src/mame/drivers/s11.cpp
@@ -14,6 +14,7 @@ ToDo:
 
     Known keys necessary to get games to start (so the proper number of balls are detected):
     - Road Kings: press 'Up' (the direction key) and Q, and press "1" after inserting 1 or more credits.
+    - High Speed: press D (ball trough center), F (ball trough lower right) and Enter (Ball Shooter) after inserting 1 or more credits.
 
 *****************************************************************************************/
 
@@ -58,10 +59,7 @@ void s11_state::s11_bg_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s11 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -71,7 +69,7 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -81,7 +79,7 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -91,7 +89,7 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -101,7 +99,7 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -111,7 +109,7 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -121,10 +119,10 @@ static INPUT_PORTS_START( s11 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DIAGS")
@@ -286,14 +284,22 @@ void s11_state::pia2c_pb_w(uint8_t data)
 
 uint8_t s11_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ~ioport(kbdrow)->read();
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	//retval &= ioport("OPTOS")->read(); // optos should be read here as well, and are always active even if no column is selected
+	return ~retval;
 }
 
 void s11_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 2N3904 NPN transistors Q42-Q49, each of which drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 void s11_state::pia34_pa_w(uint8_t data)
diff --git a/src/mame/drivers/s11a.cpp b/src/mame/drivers/s11a.cpp
index b1d793663f3..cd8436d0966 100644
--- a/src/mame/drivers/s11a.cpp
+++ b/src/mame/drivers/s11a.cpp
@@ -62,10 +62,7 @@ void s11a_state::s11a_bg_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s11a )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -75,7 +72,7 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -85,7 +82,7 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -95,7 +92,7 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -105,7 +102,7 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -115,7 +112,7 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -125,10 +122,10 @@ static INPUT_PORTS_START( s11a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DIAGS")
diff --git a/src/mame/drivers/s11b.cpp b/src/mame/drivers/s11b.cpp
index 1c9499fa456..a37e7a73a9b 100644
--- a/src/mame/drivers/s11b.cpp
+++ b/src/mame/drivers/s11b.cpp
@@ -67,10 +67,7 @@ void s11b_state::s11b_bg_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s11b )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -80,7 +77,7 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -90,7 +87,7 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -100,7 +97,7 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -110,7 +107,7 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -120,10 +117,10 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -133,7 +130,7 @@ static INPUT_PORTS_START( s11b )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DIAGS")
diff --git a/src/mame/drivers/s11c.cpp b/src/mame/drivers/s11c.cpp
index b0e0dece7bc..b34e7a3fe88 100644
--- a/src/mame/drivers/s11c.cpp
+++ b/src/mame/drivers/s11c.cpp
@@ -47,10 +47,7 @@ void s11c_state::s11c_bg_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s11c )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -60,7 +57,7 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -70,7 +67,7 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -80,7 +77,7 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -90,7 +87,7 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -100,10 +97,10 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -113,7 +110,7 @@ static INPUT_PORTS_START( s11c )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DIAGS")
diff --git a/src/mame/drivers/s3.cpp b/src/mame/drivers/s3.cpp
index 4eefea52560..1d428cd51a3 100644
--- a/src/mame/drivers/s3.cpp
+++ b/src/mame/drivers/s3.cpp
@@ -63,6 +63,7 @@ public:
 		, m_pia30(*this, "pia30")
 		, m_pias(*this, "pias")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s3a(machine_config &config);
@@ -101,7 +102,7 @@ private:
 	uint8_t m_t_c;
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	bool m_chimes;
 	virtual void machine_start() override { m_digits.resolve(); }
@@ -113,6 +114,7 @@ private:
 	required_device<pia6821_device> m_pia30;
 	optional_device<pia6821_device> m_pias;
 	output_finder<32> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s3_state::s3_main_map(address_map &map)
@@ -135,10 +137,7 @@ void s3_state::s3_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s3 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_HIGH, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_TILT ) // 3 touches before it tilts
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_START )
@@ -148,7 +147,7 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -158,7 +157,7 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -168,7 +167,7 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA) // 1 touch tilt
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -178,7 +177,7 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -188,7 +187,7 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -198,10 +197,10 @@ static INPUT_PORTS_START( s3 )
 	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_HIGH, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_HIGH, IPT_UNKNOWN )
 
 	PORT_START("SND")
@@ -412,14 +411,21 @@ void s3_state::dig1_w(uint8_t data)
 
 uint8_t s3_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read();
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	return ~retval;
 }
 
 void s3_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 7406 quad open collector inverters at IC17 and IC18, each inverter drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s3_state::sound_r()
diff --git a/src/mame/drivers/s4.cpp b/src/mame/drivers/s4.cpp
index 980c6c1ef80..9577fe4d723 100644
--- a/src/mame/drivers/s4.cpp
+++ b/src/mame/drivers/s4.cpp
@@ -57,6 +57,7 @@ public:
 		, m_pia30(*this, "pia30")
 		, m_pias(*this, "pias")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s4(machine_config &config);
@@ -95,7 +96,7 @@ private:
 	uint8_t m_t_c;
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	bool m_chimes;
 	virtual void machine_start() override { m_digits.resolve(); }
@@ -107,6 +108,7 @@ private:
 	required_device<pia6821_device> m_pia30;
 	optional_device<pia6821_device> m_pias;
 	output_finder<32> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s4_state::s4_main_map(address_map &map)
@@ -130,10 +132,7 @@ void s4_state::s4_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s4 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -143,7 +142,7 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_X)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -153,7 +152,7 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -163,7 +162,7 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -173,7 +172,7 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -183,7 +182,7 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -193,10 +192,10 @@ static INPUT_PORTS_START( s4 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("SND")
@@ -407,14 +406,21 @@ void s4_state::dig1_w(uint8_t data)
 
 uint8_t s4_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	return ~retval;
 }
 
 void s4_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 7406 quad open collector inverters at IC17 and IC18, each inverter drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s4_state::sound_r()
diff --git a/src/mame/drivers/s6.cpp b/src/mame/drivers/s6.cpp
index 814a3ab74e7..a13081a9de0 100644
--- a/src/mame/drivers/s6.cpp
+++ b/src/mame/drivers/s6.cpp
@@ -73,6 +73,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s6(machine_config &config);
@@ -109,7 +110,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	emu_timer* m_irq_timer;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
@@ -124,6 +125,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<61> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s6_state::s6_main_map(address_map &map)
@@ -147,10 +149,7 @@ void s6_state::s6_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s6 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -160,7 +159,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_X)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -170,7 +169,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -180,7 +179,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -190,7 +189,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -200,7 +199,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -210,7 +209,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_RSHIFT)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SPACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_END)
@@ -220,7 +219,7 @@ static INPUT_PORTS_START( s6 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_UNUSED )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_PGUP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_PGDN)
 	PORT_BIT( 0xfc, IP_ACTIVE_LOW, IPT_UNUSED )
@@ -346,14 +345,21 @@ void s6_state::dig1_w(uint8_t data)
 
 uint8_t s6_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	return ~retval;
 }
 
 void s6_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 7406 quad open collector inverters at IC17 and IC18, each inverter drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s6_state::sound_r()
diff --git a/src/mame/drivers/s6a.cpp b/src/mame/drivers/s6a.cpp
index 6e326c895da..dd2f07befe0 100644
--- a/src/mame/drivers/s6a.cpp
+++ b/src/mame/drivers/s6a.cpp
@@ -66,6 +66,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s6a(machine_config &config);
@@ -102,7 +103,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	emu_timer* m_irq_timer;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
@@ -117,6 +118,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<32> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s6a_state::s6a_main_map(address_map &map)
@@ -139,10 +141,7 @@ void s6a_state::s6a_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s6a )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -152,7 +151,7 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_X)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -162,7 +161,7 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -172,7 +171,7 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -182,7 +181,7 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -192,7 +191,7 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -202,10 +201,10 @@ static INPUT_PORTS_START( s6a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("SND")
@@ -329,14 +328,21 @@ void s6a_state::dig1_w(uint8_t data)
 
 uint8_t s6a_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	return ~retval;
 }
 
 void s6a_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 7406 quad open collector inverters at IC17 and IC18, each inverter drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s6a_state::sound_r()
diff --git a/src/mame/drivers/s7.cpp b/src/mame/drivers/s7.cpp
index 6979d378779..e7b170d533c 100644
--- a/src/mame/drivers/s7.cpp
+++ b/src/mame/drivers/s7.cpp
@@ -29,6 +29,8 @@ Note that T is also a tilt, but it may take 3 hits to activate it.
 A number of games are multiball therefore they either cannot start or the outhole
 is ineffective/unknown. All games can coin up.
 
+Note: fpwr2_l2 can be started by holding down D (left ball ramp) and F (ball shooter trough) when pressing start.
+
 
 Game              Outhole   Tilt        Notes
 ----------------------------------------------------------------------------------
@@ -84,6 +86,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s7(machine_config &config);
@@ -127,7 +130,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	uint8_t m_nvram[0x100];
 	bool m_data_ok;
 	bool m_memprotect;
@@ -145,6 +148,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<61> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s7_state::s7_main_map(address_map &map)
@@ -170,20 +174,18 @@ void s7_state::s7_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s7 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT ) // pendulum tilt
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_START2 ) // 2-player start
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START ) // 1-player start
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_COIN3 )
 	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_COIN2 )
 	PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_COIN1 )
-	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_TILT ) // slam tilt
+	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) // slam tilt
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_7_PAD) // high score reset
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_X)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -193,7 +195,7 @@ static INPUT_PORTS_START( s7 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -203,7 +205,7 @@ static INPUT_PORTS_START( s7 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -213,7 +215,7 @@ static INPUT_PORTS_START( s7 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -223,7 +225,7 @@ static INPUT_PORTS_START( s7 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -233,14 +235,14 @@ static INPUT_PORTS_START( s7 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_RSHIFT)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SPACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_LALT)
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_LSHIFT)
 	PORT_BIT( 0xf0, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("SND")
@@ -350,14 +352,21 @@ uint8_t s7_state::dips_r()
 
 uint8_t s7_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff; // comes in through inverter buffers
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	return ~retval;
 }
 
 void s7_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 7406 quad open collector inverters at IC17 and IC18, each inverter drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s7_state::nvram_r(offs_t offset)
diff --git a/src/mame/drivers/s8.cpp b/src/mame/drivers/s8.cpp
index e3fe43dbd8c..0666195a459 100644
--- a/src/mame/drivers/s8.cpp
+++ b/src/mame/drivers/s8.cpp
@@ -69,6 +69,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s8(machine_config &config);
@@ -103,7 +104,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	emu_timer* m_irq_timer;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
@@ -117,6 +118,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<61> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s8_state::s8_main_map(address_map &map)
@@ -139,10 +141,7 @@ void s8_state::s8_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s8 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -152,12 +151,12 @@ static INPUT_PORTS_START( s8 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_F)
 	PORT_BIT( 0xf6, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -167,21 +166,21 @@ static INPUT_PORTS_START( s8 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0xfc, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
 	PORT_START("DIAGS")
@@ -254,14 +253,22 @@ void s8_state::dig1_w(uint8_t data)
 
 uint8_t s8_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	//retval &= ioport("OPTOS")->read(); // optos should be read here as well, and are always active even if no column is selected
+	return ~retval;
 }
 
 void s8_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 2N3904 NPN transistors Q7-Q14, each of which drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s8_state::sound_r()
diff --git a/src/mame/drivers/s8a.cpp b/src/mame/drivers/s8a.cpp
index 6058a020152..ea3b4c8e189 100644
--- a/src/mame/drivers/s8a.cpp
+++ b/src/mame/drivers/s8a.cpp
@@ -45,6 +45,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s8a(machine_config &config);
@@ -79,7 +80,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	emu_timer* m_irq_timer;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
@@ -93,6 +94,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<61> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s8a_state::s8a_main_map(address_map &map)
@@ -115,10 +117,7 @@ void s8a_state::s8a_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s8a )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_COIN1 )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -128,7 +127,7 @@ static INPUT_PORTS_START( s8a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -138,22 +137,22 @@ static INPUT_PORTS_START( s8a )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
 
 	PORT_START("DIAGS")
@@ -226,14 +225,22 @@ void s8a_state::dig1_w(uint8_t data)
 
 uint8_t s8a_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	//retval &= ioport("OPTOS")->read(); // optos should be read here as well, and are always active even if no column is selected
+	return ~retval;
 }
 
 void s8a_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 2N3904 NPN transistors Q7-Q14, each of which drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s8a_state::sound_r()
diff --git a/src/mame/drivers/s9.cpp b/src/mame/drivers/s9.cpp
index a148c0d7178..e2d68835685 100644
--- a/src/mame/drivers/s9.cpp
+++ b/src/mame/drivers/s9.cpp
@@ -56,6 +56,7 @@ public:
 		, m_pia28(*this, "pia28")
 		, m_pia30(*this, "pia30")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 	{ }
 
 	void s9(machine_config &config);
@@ -90,7 +91,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	bool m_data_ok;
 	emu_timer* m_irq_timer;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
@@ -105,6 +106,7 @@ private:
 	required_device<pia6821_device> m_pia28;
 	required_device<pia6821_device> m_pia30;
 	output_finder<61> m_digits;
+	required_ioport_array<8> m_swarray;
 };
 
 void s9_state::s9_main_map(address_map &map)
@@ -127,10 +129,7 @@ void s9_state::s9_audio_map(address_map &map)
 }
 
 static INPUT_PORTS_START( s9 )
-	PORT_START("X0")
-	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNUSED )
-
-	PORT_START("X1")
+	PORT_START("SW.0")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_TILT )
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_START )
@@ -140,7 +139,7 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER )
 
-	PORT_START("X2")
+	PORT_START("SW.1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_A)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_S)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_D)
@@ -150,7 +149,7 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_J)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_K)
 
-	PORT_START("X4")
+	PORT_START("SW.2")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_L)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Z)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_C)
@@ -160,7 +159,7 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_M)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COMMA)
 
-	PORT_START("X8")
+	PORT_START("SW.3")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_STOP)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SLASH)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_COLON)
@@ -170,7 +169,7 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_EQUALS)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSPACE)
 
-	PORT_START("X10")
+	PORT_START("SW.4")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_OPENBRACE)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_CLOSEBRACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_BACKSLASH)
@@ -180,7 +179,7 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_UP)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_DOWN)
 
-	PORT_START("X20")
+	PORT_START("SW.5")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_Q)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_W)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_E)
@@ -190,14 +189,14 @@ static INPUT_PORTS_START( s9 )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_I)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_O)
 
-	PORT_START("X40")
+	PORT_START("SW.6")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_RSHIFT)
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_SPACE)
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_LALT)
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_OTHER ) PORT_CODE(KEYCODE_LSHIFT)
 	PORT_BIT( 0xf0, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
-	PORT_START("X80")
+	PORT_START("SW.7")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_UNKNOWN )
 
 	PORT_START("DIAGS")
@@ -260,14 +259,22 @@ void s9_state::dig1_w(uint8_t data)
 
 uint8_t s9_state::switch_r()
 {
-	char kbdrow[8];
-	sprintf(kbdrow,"X%X",m_kbdrow);
-	return ioport(kbdrow)->read() ^ 0xff;
+	char retval = 0xff;
+	// scan all 8 input columns, since multiple can be selected at once
+	for (int i = 0; i < 7; i++)
+	{
+		if (m_switch_col & (1<<i))
+			retval &= m_swarray[i]->read();
+	}
+	//retval &= ioport("OPTOS")->read(); // optos should be read here as well, and are always active even if no column is selected
+	return ~retval;
 }
 
 void s9_state::switch_w(uint8_t data)
 {
-	m_kbdrow = data;
+	// this drives the pulldown 2N3904 NPN transistors Q7-Q14, each of which drives one column of the switch matrix low
+	// it is possible for multiple columns to be enabled at once, this is handled in switch_r above.
+	m_switch_col = data;
 }
 
 uint8_t s9_state::sound_r()
diff --git a/src/mame/includes/s11.h b/src/mame/includes/s11.h
index 6ed840a887f..5e577008726 100644
--- a/src/mame/includes/s11.h
+++ b/src/mame/includes/s11.h
@@ -47,6 +47,7 @@ public:
 		, m_ym(*this, "ym2151")
 		, m_bg(*this, "bgm")
 		, m_digits(*this, "digit%u", 0U)
+		, m_swarray(*this, "SW.%u", 0U)
 		{ }
 
 	void s11(machine_config &config);
@@ -111,6 +112,7 @@ protected:
 	optional_device<ym2151_device> m_ym;
 	optional_device<s11c_bg_device> m_bg;
 	output_finder<63> m_digits;
+	required_ioport_array<8> m_swarray;
 
 	// getters/setters
 	uint8_t get_strobe() { return m_strobe; }
@@ -131,7 +133,7 @@ private:
 
 	uint8_t m_sound_data;
 	uint8_t m_strobe;
-	uint8_t m_kbdrow;
+	uint8_t m_switch_col;
 	uint8_t m_diag;
 	uint32_t m_segment1;
 	uint32_t m_segment2;