diff --git a/src/emu/netlist/devices/nld_7400.c b/src/emu/netlist/devices/nld_7400.c
index 46edd0038ed..758d5d1b667 100644
--- a/src/emu/netlist/devices/nld_7400.c
+++ b/src/emu/netlist/devices/nld_7400.c
@@ -9,16 +9,6 @@
 
 #if (USE_TRUTHTABLE)
 nld_7400::truthtable_t nld_7400::m_ttbl;
-
-#if 0
-const char *nld_7400::m_desc[] = {
-		"A,B,PQ,PA,PB|Q",
-		"0,X,X,X,X|1|22",
-		"X,0,X,X,X|1|22",
-		"1,1,X,X,X|0|15",
-		""
-};
-#else
 const char *nld_7400::m_desc[] = {
 		"A , B | Q ",
 		"0,X|1|22",
@@ -26,7 +16,6 @@ const char *nld_7400::m_desc[] = {
 		"1,1|0|15",
 		""
 };
-#endif
 
 #endif
 
diff --git a/src/emu/netlist/devices/nld_7402.c b/src/emu/netlist/devices/nld_7402.c
index f83a1258858..708dab04fcf 100644
--- a/src/emu/netlist/devices/nld_7402.c
+++ b/src/emu/netlist/devices/nld_7402.c
@@ -7,6 +7,18 @@
 
 #include "nld_7402.h"
 
+#if (USE_TRUTHTABLE)
+nld_7402::truthtable_t nld_7402::m_ttbl;
+const char *nld_7402::m_desc[] = {
+		"A , B | Q ",
+		"0,0|1|22",
+		"X,1|0|15",
+		"1,X|0|15",
+		""
+};
+
+#endif
+
 NETLIB_START(7402_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7402.h b/src/emu/netlist/devices/nld_7402.h
index c8e45c7f59b..bd0306cd3e1 100644
--- a/src/emu/netlist/devices/nld_7402.h
+++ b/src/emu/netlist/devices/nld_7402.h
@@ -43,7 +43,12 @@
 		NET_REGISTER_DEV(7402_dip, _name)
 
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7402, 2, 1, 0);
+#else
 NETLIB_SIGNAL(7402, 2, 1, 0);
+#endif
 
 NETLIB_DEVICE(7402_dip,
 
diff --git a/src/emu/netlist/devices/nld_7408.c b/src/emu/netlist/devices/nld_7408.c
index 9b232cce02b..4ecdc78469b 100644
--- a/src/emu/netlist/devices/nld_7408.c
+++ b/src/emu/netlist/devices/nld_7408.c
@@ -7,6 +7,18 @@
 
 #include "nld_7408.h"
 
+#if (USE_TRUTHTABLE)
+nld_7408::truthtable_t nld_7408::m_ttbl;
+const char *nld_7408::m_desc[] = {
+		"A , B | Q ",
+		"X,0|0|15",
+		"0,X|0|15",
+		"1,1|1|22",
+		""
+};
+
+#endif
+
 NETLIB_START(7408_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7408.h b/src/emu/netlist/devices/nld_7408.h
index ca17add0c03..91967fe9ba6 100644
--- a/src/emu/netlist/devices/nld_7408.h
+++ b/src/emu/netlist/devices/nld_7408.h
@@ -39,7 +39,12 @@
 		NET_CONNECT(_name, A, _A)                                                   \
 		NET_CONNECT(_name, B, _B)
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7408, 2, 1, 0);
+#else
 NETLIB_SIGNAL(7408, 2, 0, 1);
+#endif
 
 #define TTL_7408_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7408_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7410.c b/src/emu/netlist/devices/nld_7410.c
index e29b7a49605..d920398c68b 100644
--- a/src/emu/netlist/devices/nld_7410.c
+++ b/src/emu/netlist/devices/nld_7410.c
@@ -7,6 +7,20 @@
 
 #include "nld_7410.h"
 
+#if (USE_TRUTHTABLE)
+nld_7410::truthtable_t nld_7410::m_ttbl;
+const char *nld_7410::m_desc[] = {
+		"A,B,C|Q",
+		"0,X,X|1|22",
+		"X,0,X|1|22",
+		"X,X,0|1|22",
+		"1,1,1|0|15",
+		""
+};
+
+#endif
+
+
 NETLIB_START(7410_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7410.h b/src/emu/netlist/devices/nld_7410.h
index 82c6c194476..23a8fba8763 100644
--- a/src/emu/netlist/devices/nld_7410.h
+++ b/src/emu/netlist/devices/nld_7410.h
@@ -40,7 +40,12 @@
 		NET_CONNECT(_name, B, _I2)                                                  \
 		NET_CONNECT(_name, C, _I3)
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7410, 3, 1, 0);
+#else
 NETLIB_SIGNAL(7410, 3, 0, 0);
+#endif
 
 #define TTL_7410_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7410_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7411.c b/src/emu/netlist/devices/nld_7411.c
index 36a01b2b648..0664bd10c5c 100644
--- a/src/emu/netlist/devices/nld_7411.c
+++ b/src/emu/netlist/devices/nld_7411.c
@@ -7,6 +7,18 @@
 
 #include "nld_7411.h"
 
+#if (USE_TRUTHTABLE)
+nld_7411::truthtable_t nld_7411::m_ttbl;
+const char *nld_7411::m_desc[] = {
+		"A,B,C|Q",
+		"0,X,X|0|15",
+		"X,0,X|0|15",
+		"X,X,0|0|15",
+		"1,1,1|1|22",
+		""
+};
+#endif
+
 NETLIB_START(7411_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7411.h b/src/emu/netlist/devices/nld_7411.h
index 3f58b9a756d..93e7fd7f960 100644
--- a/src/emu/netlist/devices/nld_7411.h
+++ b/src/emu/netlist/devices/nld_7411.h
@@ -40,7 +40,12 @@
 		NET_CONNECT(_name, B, _I2)                                                  \
 		NET_CONNECT(_name, C, _I3)
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7411, 3, 1, 0);
+#else
 NETLIB_SIGNAL(7411, 3, 0, 1);
+#endif
 
 #define TTL_7411_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7411_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7420.c b/src/emu/netlist/devices/nld_7420.c
index 13f3e90025c..59e649fc6f6 100644
--- a/src/emu/netlist/devices/nld_7420.c
+++ b/src/emu/netlist/devices/nld_7420.c
@@ -7,6 +7,19 @@
 
 #include "nld_7420.h"
 
+#if (USE_TRUTHTABLE)
+nld_7420::truthtable_t nld_7420::m_ttbl;
+const char *nld_7420::m_desc[] = {
+		"A,B,C,D|Q",
+		"0,X,X,X|1|22",
+		"X,0,X,X|1|22",
+		"X,X,0,X|1|22",
+		"X,X,X,0|1|22",
+		"1,1,1,1|0|15",
+		""
+};
+#endif
+
 NETLIB_START(7420_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7420.h b/src/emu/netlist/devices/nld_7420.h
index 04f74c1d91c..c537cf7467b 100644
--- a/src/emu/netlist/devices/nld_7420.h
+++ b/src/emu/netlist/devices/nld_7420.h
@@ -43,7 +43,12 @@
 		NET_CONNECT(_name, D, _I4)
 
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7420, 4, 1, 0);
+#else
 NETLIB_SIGNAL(7420, 4, 0, 0);
+#endif
 
 #define TTL_7420_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7420_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7427.c b/src/emu/netlist/devices/nld_7427.c
index c24486eb8cf..a363ddd5f3c 100644
--- a/src/emu/netlist/devices/nld_7427.c
+++ b/src/emu/netlist/devices/nld_7427.c
@@ -7,6 +7,20 @@
 
 #include "nld_7427.h"
 
+#include "nld_7402.h"
+
+#if (USE_TRUTHTABLE)
+nld_7427::truthtable_t nld_7427::m_ttbl;
+const char *nld_7427::m_desc[] = {
+		"A,B,C|Q ",
+		"0,0,0|1|22",
+		"1,X,X|0|15",
+		"X,1,X|0|15",
+		"X,X,1|0|15",
+		""
+};
+#endif
+
 NETLIB_START(7427_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7427.h b/src/emu/netlist/devices/nld_7427.h
index 88dc344ea16..69d9618e246 100644
--- a/src/emu/netlist/devices/nld_7427.h
+++ b/src/emu/netlist/devices/nld_7427.h
@@ -40,7 +40,12 @@
 		NET_CONNECT(_name, B, _I2)                                                  \
 		NET_CONNECT(_name, C, _I3)
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7427, 3, 1, 0);
+#else
 NETLIB_SIGNAL(7427, 3, 1, 0);
+#endif
 
 #define TTL_7427_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7427_dip, _name)
diff --git a/src/emu/netlist/devices/nld_74279.c b/src/emu/netlist/devices/nld_74279.c
index a3260a411d6..2db7ab1d435 100644
--- a/src/emu/netlist/devices/nld_74279.c
+++ b/src/emu/netlist/devices/nld_74279.c
@@ -8,7 +8,9 @@
 #include "nld_74279.h"
 
 nld_74279A::truthtable_t nld_74279A::m_ttbl;
+nld_74279B::truthtable_t nld_74279B::m_ttbl;
 
+#if 0
 const char *nld_74279A::m_desc[] = {
 		"S,R,PQ,PS,PR|Q",
 		"0,0,X,X,X|1|22",
@@ -19,7 +21,6 @@ const char *nld_74279A::m_desc[] = {
 		""
 };
 
-nld_74279B::truthtable_t nld_74279B::m_ttbl;
 
 const char *nld_74279B::m_desc[] = {
 		"S1,S2,R,PQ,PS1,PS2,PR|Q",
@@ -32,6 +33,29 @@ const char *nld_74279B::m_desc[] = {
 		"1,1,1,1,X,X,X|1|22",
 		""
 };
+#else
+const char *nld_74279A::m_desc[] = {
+		"S,R,_Q|Q",
+		"0,X,X|1|22",
+		"1,0,X|0|27",
+		"1,1,0|0|27", //15
+		"1,1,1|1|22",
+		""
+};
+
+
+const char *nld_74279B::m_desc[] = {
+		"S1,S2,R,_Q|Q",
+		"0,X,X,X|1|22",
+		"X,0,X,X|1|22",
+		"1,1,0,X|0|27",
+		"1,1,1,0|0|27", // 15
+		"1,1,1,1|1|22",
+		""
+};
+
+#endif
+
 
 NETLIB_START(74279_dip)
 {
diff --git a/src/emu/netlist/devices/nld_74279.h b/src/emu/netlist/devices/nld_74279.h
index ae5020394de..156b59b2b31 100644
--- a/src/emu/netlist/devices/nld_74279.h
+++ b/src/emu/netlist/devices/nld_74279.h
@@ -3,7 +3,7 @@
 /*
  * nld_74279.h
  *
- *  DM74279: Triple 3-Input NAND Gates
+ *  DM74279: Quad S-R Latch
  *
  *          +--------------+
  *       1R |1     ++    16| VCC
@@ -38,9 +38,13 @@
 
 #include "nld_truthtable.h"
 
+#if 0
 NETLIB_TRUTHTABLE(74279A, 2, 1, 1);
 NETLIB_TRUTHTABLE(74279B, 3, 1, 1);
-
+#else
+NETLIB_TRUTHTABLE(74279A, 3, 1, 0);
+NETLIB_TRUTHTABLE(74279B, 4, 1, 0);
+#endif
 #define TTL_74279_DIP(_name)                                                         \
 		NET_REGISTER_DEV(74279_dip, _name)
 
diff --git a/src/emu/netlist/devices/nld_7430.c b/src/emu/netlist/devices/nld_7430.c
index c0af72c4b95..06d73997ad5 100644
--- a/src/emu/netlist/devices/nld_7430.c
+++ b/src/emu/netlist/devices/nld_7430.c
@@ -7,6 +7,25 @@
 
 #include "nld_7430.h"
 
+#if (USE_TRUTHTABLE)
+nld_7430::truthtable_t nld_7430::m_ttbl;
+const char *nld_7430::m_desc[] = {
+		"A,B,C,D,E,F,G,H|Q ",
+		"0,X,X,X,X,X,X,X|1|22",
+		"X,0,X,X,X,X,X,X|1|22",
+		"X,X,0,X,X,X,X,X|1|22",
+		"X,X,X,0,X,X,X,X|1|22",
+		"X,X,X,X,0,X,X,X|1|22",
+		"X,X,X,X,X,0,X,X|1|22",
+		"X,X,X,X,X,X,0,X|1|22",
+		"X,X,X,X,X,X,X,0|1|22",
+		"1,1,1,1,1,1,1,1|0|15",
+		""
+};
+
+#endif
+
+
 NETLIB_START(7430_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7430.h b/src/emu/netlist/devices/nld_7430.h
index 7530380d216..ed6e239a1b5 100644
--- a/src/emu/netlist/devices/nld_7430.h
+++ b/src/emu/netlist/devices/nld_7430.h
@@ -51,7 +51,12 @@
 		NET_CONNECT(_name, H, _I8)
 
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7430, 8, 1, 0);
+#else
 NETLIB_SIGNAL(7430, 8, 0, 0);
+#endif
 
 #define TTL_7430_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7430_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7432.c b/src/emu/netlist/devices/nld_7432.c
index b952a1a3c20..e3dda241be7 100644
--- a/src/emu/netlist/devices/nld_7432.c
+++ b/src/emu/netlist/devices/nld_7432.c
@@ -7,6 +7,18 @@
 
 #include "nld_7432.h"
 
+#if (USE_TRUTHTABLE)
+nld_7432::truthtable_t nld_7432::m_ttbl;
+const char *nld_7432::m_desc[] = {
+		"A,B|Q ",
+		"1,X|1|22",
+		"0,1|1|22",
+		"0,0|0|15",
+		""
+};
+
+#endif
+
 NETLIB_START(7432_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7432.h b/src/emu/netlist/devices/nld_7432.h
index 97992807857..b81bc74cb26 100644
--- a/src/emu/netlist/devices/nld_7432.h
+++ b/src/emu/netlist/devices/nld_7432.h
@@ -43,7 +43,12 @@
 		NET_REGISTER_DEV(7432_dip, _name)
 
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7432, 2, 1, 0);
+#else
 NETLIB_SIGNAL(7432, 2, 1, 1);
+#endif
 
 NETLIB_DEVICE(7432_dip,
 
diff --git a/src/emu/netlist/devices/nld_9312.c b/src/emu/netlist/devices/nld_9312.c
index 7fa4e5b43c6..40b924bdf47 100644
--- a/src/emu/netlist/devices/nld_9312.c
+++ b/src/emu/netlist/devices/nld_9312.c
@@ -22,7 +22,7 @@
 */
 #include "nld_9312.h"
 
-#if (USE_TRUTHTABLE)
+#if (1 && USE_TRUTHTABLE)
 nld_9312::truthtable_t nld_9312::m_ttbl;
 
 /* FIXME: Data changes are propagating faster than changing selects A,B,C
@@ -57,25 +57,26 @@ const char *nld_9312::m_desc[] = {
 NETLIB_UPDATE(9312)
 {
 	const UINT8 G = INPLOGIC(m_G);
-	if ((m_last_G ^ G) == 1)
+	if (G)
 	{
 		static const netlist_time delay[2] = { NLTIME_FROM_NS(33), NLTIME_FROM_NS(19) };
-		OUTLOGIC(m_Y, !G, delay[!G]);
-		OUTLOGIC(m_YQ, G, delay[G]);
-		if (G)
+		OUTLOGIC(m_Y, 0, delay[0]);
+		OUTLOGIC(m_YQ, 1, delay[1]);
+
+		m_A.inactivate();
+		m_B.inactivate();
+		m_C.inactivate();
+		m_last_G = G;
+	}
+	else
+	{
+		if (m_last_G)
 		{
-			m_A.inactivate();
-			m_B.inactivate();
-			m_C.inactivate();
-		} else {
+			m_last_G = G;
 			m_A.activate();
 			m_B.activate();
 			m_C.activate();
 		}
-		m_last_G = G;
-	}
-	if (!G)
-	{
 		static const netlist_time delay[2] = { NLTIME_FROM_NS(33), NLTIME_FROM_NS(28) };
 		const UINT8 chan = INPLOGIC(m_A) | (INPLOGIC(m_B)<<1) | (INPLOGIC(m_C)<<2);
 		if (m_last_chan != chan)
@@ -125,7 +126,7 @@ NETLIB_START(9312_dip)
 {
 	register_sub("1", m_sub);
 
-#if (USE_TRUTHTABLE)
+#if (1 && USE_TRUTHTABLE)
 
 	register_subalias("13", m_sub.m_i[0]);
 	register_subalias("12", m_sub.m_i[1]);
diff --git a/src/emu/netlist/devices/nld_9312.h b/src/emu/netlist/devices/nld_9312.h
index 32eabe68506..f8634bb9053 100644
--- a/src/emu/netlist/devices/nld_9312.h
+++ b/src/emu/netlist/devices/nld_9312.h
@@ -43,6 +43,10 @@
 		NET_REGISTER_DEV(9312, _name)
 #if (USE_TRUTHTABLE)
 #include "nld_truthtable.h"
+
+/* The truthtable implementation is a lot faster than
+ * the carefully crafted code :-(
+ */
 NETLIB_TRUTHTABLE(9312, 12, 2, 0);
 #else
 
diff --git a/src/emu/netlist/devices/nld_ne555.c b/src/emu/netlist/devices/nld_ne555.c
index bb78707c148..8caf08e024b 100644
--- a/src/emu/netlist/devices/nld_ne555.c
+++ b/src/emu/netlist/devices/nld_ne555.c
@@ -60,7 +60,7 @@ NETLIB_RESET(NE555)
 	m_R3.set_R(5000);
 	m_RDIS.set_R(R_OFF);
 
-	m_last_out = false;
+	m_last_out = true;
 }
 
 NETLIB_UPDATE(NE555)
diff --git a/src/emu/netlist/devices/nld_truthtable.h b/src/emu/netlist/devices/nld_truthtable.h
index 4da8f44e7fb..2ab64bc8b42 100644
--- a/src/emu/netlist/devices/nld_truthtable.h
+++ b/src/emu/netlist/devices/nld_truthtable.h
@@ -24,6 +24,35 @@
 	}
 
 
+static inline UINT32 remove_first_bit(UINT32 v)
+{
+	for (int i=0; i<32; i++)
+		if (v & (1<<i))
+			return v & ~(1<<i);
+	return v;
+}
+
+static inline int count_bits(UINT32 v)
+{
+	int ret = 0;
+	for (int i=0; i<32; i++)
+		if (v & (1<<i))
+			ret++;
+	return ret;
+}
+
+static inline UINT32 set_bits(UINT32 v, UINT32 b)
+{
+	UINT32 ret = 0;
+	for (int i=0; i<32; i++)
+		if (v & (1<<i))
+		{
+			ret |= ((b&1)<<i);
+			b = b >> 1;
+		}
+	return ret;
+}
+
 template<int m_NI, int m_NO, int has_state>
 class nld_truthtable_t : public netlist_device_t
 {
@@ -36,7 +65,7 @@ public:
 	{
 		truthtable_t() : m_initialized(false) {}
 		UINT32 m_outs[m_size];
-		UINT8  m_timing[m_size][m_NO];
+		UINT8  m_timing[m_size * m_NO];
 		netlist_time m_timing_nt[16];
 		bool m_initialized;
 	};
@@ -49,22 +78,37 @@ public:
 	ATTR_COLD virtual void start()
 	{
 		pstring ttline = pstring(m_desc[0]);
-		{
-			nl_util::pstring_list io = nl_util::split(ttline,"|");
-			// checks
-			nl_assert_always(io.count() == 2, "too many '|'");
-			nl_util::pstring_list inout = nl_util::split(io[0], ",");
-			nl_assert_always(inout.count() == m_num_bits, "bitcount wrong");
-			nl_util::pstring_list out = nl_util::split(io[1], ",");
-			nl_assert_always(out.count() == m_NO, "output count wrong");
 
-			for (int i=0; i < m_NI; i++)
-			{
-				register_input(inout[i].trim(), m_i[i]);
-			}
+		nl_util::pstring_list io = nl_util::split(ttline,"|");
+		// checks
+		nl_assert_always(io.count() == 2, "too many '|'");
+		nl_util::pstring_list inout = nl_util::split(io[0], ",");
+		nl_assert_always(inout.count() == m_num_bits, "bitcount wrong");
+		nl_util::pstring_list out = nl_util::split(io[1], ",");
+		nl_assert_always(out.count() == m_NO, "output count wrong");
+
+		for (int i=0; i < m_NI; i++)
+		{
+			inout[i] = inout[i].trim();
+			register_input(inout[i], m_i[i]);
+		}
+		for (int i=0; i < m_NO; i++)
+		{
+			out[i] = out[i].trim();
+			register_output(out[i], m_Q[i]);
+		}
+		{
+			// Connect output "Q" to input "_Q" if this exists
+			// This enables timed state without having explicit state ....
 			for (int i=0; i < m_NO; i++)
 			{
-				register_output(out[i].trim(), m_Q[i]);
+				pstring tmp = "_" + out[i];
+				const int idx = inout.indexof(tmp);
+				if (idx>=0)
+				{
+					//printf("connecting %s %d\n", out[i].cstr(), idx);
+					connect(m_Q[i], m_i[idx]);
+				}
 			}
 		}
 		m_ign = 0;
@@ -73,12 +117,11 @@ public:
 	}
 
 	ATTR_COLD void help(int cur, nl_util::pstring_list list,
-			UINT64 state, UINT64 ignore, UINT16 val, UINT8 timing_index[m_NO])
+			UINT64 state,UINT16 val, UINT8 timing_index[m_NO])
 	{
 		pstring elem = list[cur].trim();
 		int start = 0;
 		int end = 0;
-		int ign = 0;
 
 		if (elem.equals("0"))
 		{
@@ -94,25 +137,23 @@ public:
 		{
 			start = 0;
 			end = 1;
-			ign = 1;
 		}
 		else
 			nl_assert_always(false, "unknown input value (not 0, 1, or X)");
 		for (int i = start; i <= end; i++)
 		{
 			const UINT64 nstate = state | (i << cur);
-			const UINT64 nignore = ignore | (ign << cur);
 
 			if (cur < m_num_bits - 1)
 			{
-				help(cur + 1, list, nstate, nignore, val, timing_index);
+				help(cur + 1, list, nstate, val, timing_index);
 			}
 			else
 			{
 				// cutoff previous inputs and outputs for ignore
-				m_ttp->m_outs[nstate] = val | ((nignore & ((1 << m_NI)-1)) << m_NO);
+				m_ttp->m_outs[nstate] = val;
 				for (int j=0; j<m_NO; j++)
-					m_ttp->m_timing[nstate][j] = timing_index[j];
+					m_ttp->m_timing[nstate * m_NO + j] = timing_index[j];
 			}
 		}
 	}
@@ -163,11 +204,72 @@ public:
 				tindex[j] = k;
 			}
 
-			help(0, inout, 0 , 0 , val, tindex);
+			help(0, inout, 0 , val, tindex);
 			ttline = pstring(truthtable[0]);
 			truthtable++;
 		}
+
+		// ((nignore & ((1 << m_NI)-1)) << m_NO)
+
+		// determine ignore
+		UINT32 ign[m_size];
+
+		for (int i=0; i<m_size; i++)
+		{
+#if 1
+			UINT32 m_enable = 0;
+			for (int j=0; j<m_size; j++)
+			{
+				if (m_ttp->m_outs[j] != m_ttp->m_outs[i])
+				{
+					m_enable |= (i ^ j);
+				}
+			}
+			ign[i] = m_enable ^ (m_size - 1);
+#else
+			// this doesn't work in all cases and is dog slow
+			UINT32 nign = 0;
+			for (int j=0; j<m_NI; j++)
+			{
+				if (m_ttp->m_outs[i] == m_ttp->m_outs[i ^ (1 << j)])
+					nign |= (1<<j);
+			}
+			/* Check all permutations of ign
+			 */
+			int t[1<<count_bits(nign)];
+
+			for (UINT32 j=0; j<(1<<count_bits(nign)); j++)
+			{
+				UINT32 tign = set_bits(nign, j);
+				t[j] = 0;
+				for (UINT32 k=0; k<(1<<count_bits(tign)); k++)
+				{
+					UINT32 b=set_bits(tign, k);
+					if (m_ttp->m_outs[i] != m_ttp->m_outs[(i & ~tign) | b])
+						t[j] = 1;
+				}
+				//printf("x %d %d\n", j, tign);
+			}
+			UINT32 jb=0;
+			UINT32 jm=0;
+			for (UINT32 j=0; j<(1<<count_bits(nign)); j++)
+			{
+				int nb = count_bits(j);
+				if ((t[j] == 0)&& (nb>jb))
+				{
+					jb = nb;
+					jm = j;
+				}
+			}
+			ign[i] = set_bits(nign, jm);
+#endif
+		}
+		for (int i=0; i<m_size; i++)
+		{
+			m_ttp->m_outs[i] |= (ign[i] << m_NO);
+		}
 #if 0
+		printf("%s\n", name().cstr());
 		for (int j=0; j < m_size; j++)
 			printf("%05x %04x %04x %04x\n", j, m_ttp->m_outs[j] & ((1 << m_NO)-1),
 					m_ttp->m_outs[j] >> m_NO, m_ttp->m_timing[j][0]);
@@ -217,14 +319,15 @@ public:
 			if (m_ign & (1 << i))
 				m_i[i].inactivate();
 
+		const UINT32 timebase = nstate * m_NO;
 		if (doOUT)
 		{
 			for (int i = 0; i < m_NO; i++)
-				OUTLOGIC(m_Q[i], (out >> i) & 1, m_ttp->m_timing_nt[m_ttp->m_timing[nstate][i]]);
+				OUTLOGIC(m_Q[i], (out >> i) & 1, m_ttp->m_timing_nt[m_ttp->m_timing[timebase + i]]);
 		}
 		else
 			for (int i = 0; i < m_NO; i++)
-				m_Q[i].net().set_Q_time((out >> i) & 1, mt + m_ttp->m_timing_nt[m_ttp->m_timing[nstate][i]]);
+				m_Q[i].net().set_Q_time((out >> i) & 1, mt + m_ttp->m_timing_nt[m_ttp->m_timing[timebase + i]]);
 
 	}
 
diff --git a/src/emu/netlist/nl_base.c b/src/emu/netlist/nl_base.c
index a71fcc97218..dfd7c84e76d 100644
--- a/src/emu/netlist/nl_base.c
+++ b/src/emu/netlist/nl_base.c
@@ -386,8 +386,12 @@ ATTR_COLD void netlist_core_device_t::init(netlist_base_t &anetlist, const pstri
 
 #if USE_PMFDELEGATES
 	void (netlist_core_device_t::* pFunc)() = &netlist_core_device_t::update;
+#if NO_USE_PMFCONVERSION
+	static_update = pFunc;
+#else
 	static_update = reinterpret_cast<net_update_delegate>((this->*pFunc));
 #endif
+#endif
 
 }
 
@@ -1019,7 +1023,10 @@ ATTR_COLD nl_double netlist_param_model_t::model_value(const pstring &entity, co
 		return atof(tmp.cstr()) * factor;
 	}
 	else
+	{
+		netlist().log("Entity %s not found in model %s\n", entity.cstr(), tmp.cstr());
 		return defval;
+	}
 }
 
 
diff --git a/src/emu/netlist/nl_base.h b/src/emu/netlist/nl_base.h
index 4fddb58c22b..dfac03a7491 100644
--- a/src/emu/netlist/nl_base.h
+++ b/src/emu/netlist/nl_base.h
@@ -173,8 +173,12 @@
 class netlist_core_device_t;
 
 #if USE_PMFDELEGATES
+#if NO_USE_PMFCONVERSION
+typedef void (netlist_core_device_t::*net_update_delegate)();
+#else
 typedef void (*net_update_delegate)(netlist_core_device_t *);
 #endif
+#endif
 
 //============================================================
 //  MACROS / netlist devices
@@ -972,7 +976,11 @@ public:
 		begin_timing(stat_total_time);
 		inc_stat(stat_update_count);
 #if USE_PMFDELEGATES
+#if	NO_USE_PMFCONVERSION
+		(this->*static_update)();
+#else
 		static_update(this);
+#endif
 #else
 		update();
 #endif
diff --git a/src/emu/netlist/nl_config.h b/src/emu/netlist/nl_config.h
index 387c2dcdd17..912127f208d 100644
--- a/src/emu/netlist/nl_config.h
+++ b/src/emu/netlist/nl_config.h
@@ -23,13 +23,28 @@
 
 /*
  * The next options needs -Wno-pmf-conversions to compile and gcc
- * This is intended for non-mame usage.
+ * There is quite some significant speed-up of up to 20% involved.
+ * NO_USE_PMFCONVERSION is for illustrative purposes only. Using PMFs
+ * has some overhead in comparison to calling a virtual function.
+ *
+ * To get a performance increase we need the GCC extension.
  *
  */
-#define USE_PMFDELEGATES        (0)
 
-#if (USE_PMFDELEGATES)
-#pragma GCC diagnostic ignored "-Wpmf-conversions"
+#ifndef USE_PMFDELEGATES
+#if defined(__clang__)
+	#define USE_PMFDELEGATES        	(0)
+	#define NO_USE_PMFCONVERSION		(1)
+#else
+	#if defined(__GNUC__)
+		#define USE_PMFDELEGATES        (1)
+		#define NO_USE_PMFCONVERSION	(0)
+		#pragma GCC diagnostic ignored "-Wpmf-conversions"
+	#else
+		#define USE_PMFDELEGATES        (0)
+		#define NO_USE_PMFCONVERSION	(1)
+	#endif
+#endif
 #endif
 
 /*
@@ -44,7 +59,7 @@
 // moved to parameter NETLIST.USE_DEACTIVATE
 // #define USE_DEACTIVE_DEVICE     (0)
 
-#define USE_TRUTHTABLE          (0)
+#define USE_TRUTHTABLE          (1)
 
 // The following adds about 10% performance ...
 
diff --git a/src/mame/drivers/nl_breakout.c b/src/mame/drivers/nl_breakout.c
index cbd26627466..dbc5ece001b 100644
--- a/src/mame/drivers/nl_breakout.c
+++ b/src/mame/drivers/nl_breakout.c
@@ -114,7 +114,7 @@ CIRCUIT_LAYOUT( breakout )
     // FIXME: PARALLEL Doesn't work in breakout.
     PARAM(Solver.PARALLEL, 0)
 #endif
-    //PARAM(NETLIST.USE_DEACTIVATE, 1)
+    PARAM(NETLIST.USE_DEACTIVATE, 1)
 
 	// DIPSWITCH - Free game
 	SWITCH(S1_1)
diff --git a/src/mame/drivers/nl_pong.c b/src/mame/drivers/nl_pong.c
index 9c2779b49db..2c89fcb7ebe 100644
--- a/src/mame/drivers/nl_pong.c
+++ b/src/mame/drivers/nl_pong.c
@@ -14,6 +14,7 @@ NETLIST_START(pong_fast)
 	PARAM(Solver.PARALLEL, 0) // Don't do parallel solvers
 	PARAM(Solver.ACCURACY, 1e-4) // works and is sufficient
 	PARAM(Solver.LTE,     1e-4) // Default is not enough for paddle control if using LTE
+    PARAM(NETLIST.USE_DEACTIVATE, 1)
 
 	ANALOG_INPUT(V5, 5)