diff --git a/src/mame/drivers/ympsr340.cpp b/src/mame/drivers/ympsr340.cpp
index fd7f3171cd0..762c62ba8ae 100644
--- a/src/mame/drivers/ympsr340.cpp
+++ b/src/mame/drivers/ympsr340.cpp
@@ -65,13 +65,13 @@ private:
 
 u8 psr340_state::matrix_r()
 {
-	u8 data = 0x3f;
+	u8 data = 0;
 
 	for (int i = 0; i < 8; i++)
 	{
 		if (!BIT(m_matrixsel, i))
 		{
-			data &= m_key[i]->read();
+			data |= m_key[i]->read();
 		}
 	}
 
@@ -99,6 +99,8 @@ void psr340_state::psr340_map(address_map &map)
 
 	map(0x600000, 0x600000).lr8(NAME([]() -> uint8_t { return 0x80; }));    // FDC status
 
+	map(0xffe000, 0xffe7ff).ram();
+
 	map(0xffe027, 0xffe027).r(FUNC(psr340_state::matrix_r));
 
 	map(0xffe02a, 0xffe02a).w(FUNC(psr340_state::lcd_ctrl_w));
@@ -156,68 +158,68 @@ WRITE_LINE_MEMBER(psr340_state::render_w)
 
 static INPUT_PORTS_START(psr340)
 	PORT_START("SA")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Song") PORT_CODE(KEYCODE_Z)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Record") PORT_CODE(KEYCODE_X)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Main A") PORT_CODE(KEYCODE_C)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("-") PORT_CODE(KEYCODE_LEFT)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("2") PORT_CODE(KEYCODE_2)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Execute") PORT_CODE(KEYCODE_ENTER)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Song") PORT_CODE(KEYCODE_Z)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Record") PORT_CODE(KEYCODE_X)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Main A") PORT_CODE(KEYCODE_C)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("-") PORT_CODE(KEYCODE_LEFT)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("2") PORT_CODE(KEYCODE_2)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Execute") PORT_CODE(KEYCODE_ENTER)
 
 	PORT_START("SB")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Function") PORT_CODE(KEYCODE_A)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Dual") PORT_CODE(KEYCODE_A)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Intro/End") PORT_CODE(KEYCODE_S)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Metronome") PORT_CODE(KEYCODE_D)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("0") PORT_CODE(KEYCODE_0)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Tenkey +") PORT_CODE(KEYCODE_EQUALS)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Function") PORT_CODE(KEYCODE_A)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Dual") PORT_CODE(KEYCODE_S)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Intro/End") PORT_CODE(KEYCODE_D)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Metronome") PORT_CODE(KEYCODE_F)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("0") PORT_CODE(KEYCODE_0)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Tenkey +") PORT_CODE(KEYCODE_EQUALS)
 
 	PORT_START("SC")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S. 6") PORT_CODE(KEYCODE_Y)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Touch") PORT_CODE(KEYCODE_F)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Start/Stop") PORT_CODE(KEYCODE_G)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Porta Grand") PORT_CODE(KEYCODE_H)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Tenkey -") PORT_CODE(KEYCODE_MINUS)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("7") PORT_CODE(KEYCODE_7)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S. 6") PORT_CODE(KEYCODE_Y)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Touch") PORT_CODE(KEYCODE_G)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Start/Stop") PORT_CODE(KEYCODE_H)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Porta Grand") PORT_CODE(KEYCODE_J)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Tenkey -") PORT_CODE(KEYCODE_MINUS)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("7") PORT_CODE(KEYCODE_7)
 
 	PORT_START("SD")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S 5") PORT_CODE(KEYCODE_T)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Harmony") PORT_CODE(KEYCODE_Z)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Sync Start") PORT_CODE(KEYCODE_X)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Utility") PORT_CODE(KEYCODE_C)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("8") PORT_CODE(KEYCODE_8)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("9") PORT_CODE(KEYCODE_9)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S 5") PORT_CODE(KEYCODE_T)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Harmony") PORT_CODE(KEYCODE_Z)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Sync Start") PORT_CODE(KEYCODE_X)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Utility") PORT_CODE(KEYCODE_C)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("8") PORT_CODE(KEYCODE_8)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("9") PORT_CODE(KEYCODE_9)
 
 	PORT_START("SE")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S. 4") PORT_CODE(KEYCODE_R)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Reverb") PORT_CODE(KEYCODE_V)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Accomp On") PORT_CODE(KEYCODE_N)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Save") PORT_CODE(KEYCODE_M)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("5") PORT_CODE(KEYCODE_5)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("6") PORT_CODE(KEYCODE_6)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S. 4") PORT_CODE(KEYCODE_R)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Reverb") PORT_CODE(KEYCODE_V)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Accomp On") PORT_CODE(KEYCODE_N)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Save") PORT_CODE(KEYCODE_M)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("5") PORT_CODE(KEYCODE_5)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("6") PORT_CODE(KEYCODE_6)
 
 	PORT_START("SF")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S. 3") PORT_CODE(KEYCODE_E)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Demo") PORT_CODE(KEYCODE_COMMA)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Load") PORT_CODE(KEYCODE_STOP)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("+") PORT_CODE(KEYCODE_RIGHT)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("4") PORT_CODE(KEYCODE_4)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S. 3") PORT_CODE(KEYCODE_E)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Demo") PORT_CODE(KEYCODE_COMMA)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_UNUSED)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Load") PORT_CODE(KEYCODE_STOP)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("+") PORT_CODE(KEYCODE_RIGHT)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("4") PORT_CODE(KEYCODE_4)
 
 	PORT_START("SG")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S. 2") PORT_CODE(KEYCODE_W)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Chord Guide") PORT_CODE(KEYCODE_SPACE)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Voice") PORT_CODE(KEYCODE_SLASH)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Up") PORT_CODE(KEYCODE_UP)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("1") PORT_CODE(KEYCODE_1)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S. 2") PORT_CODE(KEYCODE_W)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Chord Guide") PORT_CODE(KEYCODE_SPACE)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_UNUSED)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Voice") PORT_CODE(KEYCODE_SLASH)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Up") PORT_CODE(KEYCODE_UP)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("1") PORT_CODE(KEYCODE_1)
 
 	PORT_START("SH")
-	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("O.T.S. 1") PORT_CODE(KEYCODE_Q)
-	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Main B") PORT_CODE(KEYCODE_LSHIFT)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Style") PORT_CODE(KEYCODE_LCONTROL)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("Down") PORT_CODE(KEYCODE_RIGHT)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_OTHER) PORT_NAME("3") PORT_CODE(KEYCODE_3)
+	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("O.T.S. 1") PORT_CODE(KEYCODE_Q)
+	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Main B") PORT_CODE(KEYCODE_LSHIFT)
+	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_UNUSED)
+	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Style") PORT_CODE(KEYCODE_LCONTROL)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("Down") PORT_CODE(KEYCODE_DOWN)
+	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_OTHER) PORT_NAME("3") PORT_CODE(KEYCODE_3)
 INPUT_PORTS_END
 
 void psr340_state::psr340(machine_config &config)