diff --git a/src/emu/netlist/devices/nld_7437.c b/src/emu/netlist/devices/nld_7437.c
index bcbbb5cf575..ba078f81d11 100644
--- a/src/emu/netlist/devices/nld_7437.c
+++ b/src/emu/netlist/devices/nld_7437.c
@@ -7,6 +7,18 @@
 
 #include "nld_7437.h"
 
+#if (USE_TRUTHTABLE)
+nld_7437::truthtable_t nld_7437::m_ttbl;
+const char *nld_7437::m_desc[] = {
+		"A , B | Q ",
+		"0,X|1|22",
+		"X,0|1|22",
+		"1,1|0|15",
+		""
+};
+
+#endif
+
 NETLIB_START(7437_dip)
 {
 	register_sub("1", m_1);
diff --git a/src/emu/netlist/devices/nld_7437.h b/src/emu/netlist/devices/nld_7437.h
index e83e8c2a737..03145ee8a8c 100644
--- a/src/emu/netlist/devices/nld_7437.h
+++ b/src/emu/netlist/devices/nld_7437.h
@@ -42,7 +42,12 @@
 		NET_CONNECT(_name, A, _A)                                                   \
 		NET_CONNECT(_name, B, _B)
 
+#if (USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+NETLIB_TRUTHTABLE(7437, 2, 1, 0);
+#else
 NETLIB_SIGNAL(7437, 2, 0, 0);
+#endif
 
 #define TTL_7437_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7437_dip, _name)
diff --git a/src/emu/netlist/devices/nld_7448.c b/src/emu/netlist/devices/nld_7448.c
index aea9b2f7620..a761856f59e 100644
--- a/src/emu/netlist/devices/nld_7448.c
+++ b/src/emu/netlist/devices/nld_7448.c
@@ -7,8 +7,60 @@
 
 #include "nld_7448.h"
 
+#if (0 && USE_TRUTHTABLE)
+nld_7448::truthtable_t nld_7448::m_ttbl;
+const char *nld_7448::m_desc[] = {
+		" LTQ,BIQ,RBIQ, A , B , C , D | a, b, c, d, e, f, g",
 
+		"  1,  1,  1,   0,  0,  0,  0 | 1, 1, 1, 1, 1, 1, 0|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  0,  0,  0 | 0, 1, 1, 0, 0, 0, 0|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  1,  0,  0 | 1, 1, 0, 1, 1, 0, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  1,  0,  0 | 1, 1, 1, 1, 0, 0, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  0,  1,  0 | 0, 1, 1, 0, 0, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  0,  1,  0 | 1, 0, 1, 1, 0, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  1,  1,  0 | 0, 0, 1, 1, 1, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  1,  1,  0 | 1, 1, 1, 0, 0, 0, 0|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  0,  0,  1 | 1, 1, 1, 1, 1, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  0,  0,  1 | 1, 1, 1, 0, 0, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  1,  0,  1 | 0, 0, 0, 1, 1, 0, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  1,  0,  1 | 0, 0, 1, 1, 0, 0, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  0,  1,  1 | 0, 1, 0, 0, 0, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  0,  1,  1 | 1, 0, 0, 1, 0, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   0,  1,  1,  1 | 0, 0, 0, 1, 1, 1, 1|100,100,100,100,100,100,100",
+		"  1,  1,  X,   1,  1,  1,  1 | 0, 0, 0, 0, 0, 0, 0|100,100,100,100,100,100,100",
 
+		// BI/RBO is input output. In the next case it is used as an output will go low.
+		"  1,  1,  0,   0,  0,  0,  0 | 0, 0, 0, 0, 0, 0, 0|100,100,100,100,100,100,100", // RBI
+
+		"  0,  1,  X,   X,  X,  X,  X | 1, 1, 1, 1, 1, 1, 1|100,100,100,100,100,100,100", // LT
+
+		// This condition has precedence
+		"  X,  0,  X,   X,  X,  X,  X | 0, 0, 0, 0, 0, 0, 0|100,100,100,100,100,100,100", // BI
+		""
+};
+
+NETLIB_START(7448_dip)
+{
+	NETLIB_NAME(7448)::start();
+
+	register_subalias("1", m_i[4]); // B
+	register_subalias("2", m_i[5]); // C
+	register_subalias("3", m_i[0]); // LTQ
+	register_subalias("4", m_i[1]); // BIQ
+	register_subalias("5", m_i[2]); // RBIQ
+	register_subalias("6", m_i[6]); // D
+	register_subalias("7", m_i[3]); // A
+
+	register_subalias("9",  m_Q[4]); // e
+	register_subalias("10", m_Q[3]); // d
+	register_subalias("11", m_Q[2]); // c
+	register_subalias("12", m_Q[1]); // b
+	register_subalias("13", m_Q[0]); // a
+	register_subalias("14", m_Q[6]); // g
+	register_subalias("15", m_Q[5]); // f
+}
+
+#else
 NETLIB_START(7448)
 {
 	register_sub("sub", sub);
@@ -21,15 +73,17 @@ NETLIB_START(7448)
 	register_input("BIQ", m_BIQ);
 	register_subalias("RBIQ",sub.m_RBIQ);
 
-	register_subalias("a", sub.m_a);
-	register_subalias("b", sub.m_b);
-	register_subalias("c", sub.m_c);
-	register_subalias("d", sub.m_d);
-	register_subalias("e", sub.m_e);
-	register_subalias("f", sub.m_f);
-	register_subalias("g", sub.m_g);
+	register_subalias("a", sub.m_Q[0]);
+	register_subalias("b", sub.m_Q[1]);
+	register_subalias("c", sub.m_Q[2]);
+	register_subalias("d", sub.m_Q[3]);
+	register_subalias("e", sub.m_Q[4]);
+	register_subalias("f", sub.m_Q[5]);
+	register_subalias("g", sub.m_Q[6]);
+
 }
 
+
 NETLIB_RESET(7448)
 {
 	sub.do_reset();
@@ -72,20 +126,22 @@ NETLIB_START(7448_sub)
 	register_input("A3", m_D);
 	register_input("RBIQ", m_RBIQ);
 
-	register_output("a", m_a);
-	register_output("b", m_b);
-	register_output("c", m_c);
-	register_output("d", m_d);
-	register_output("e", m_e);
-	register_output("f", m_f);
-	register_output("g", m_g);
+	register_output("a", m_Q[0]);
+	register_output("b", m_Q[1]);
+	register_output("c", m_Q[2]);
+	register_output("d", m_Q[3]);
+	register_output("e", m_Q[4]);
+	register_output("f", m_Q[5]);
+	register_output("g", m_Q[6]);
 
 	save(NLNAME(m_state));
+	save(NLNAME(m_active));
 }
 
 NETLIB_RESET(7448_sub)
 {
 	m_state = 0;
+	m_active = 7;
 }
 
 NETLIB_UPDATE(7448_sub)
@@ -98,6 +154,45 @@ NETLIB_UPDATE(7448_sub)
 	update_outputs(v);
 }
 
+#if 0
+ATTR_HOT void NETLIB_NAME(7448_sub)::inc_active()
+{
+	const netlist_time delay[2] = { NLTIME_FROM_NS(15), NLTIME_FROM_NS(22) };
+	nl_assert(netlist().use_deactivate());
+	if (++m_active == 1)
+	{
+		m_A.activate();
+		m_B.activate();
+		m_C.activate();
+		m_D.activate();
+		m_RBIQ.activate();
+
+		netlist_time mt = this->m_Q[0].net().time();
+		for (int i=1; i<7; i++)
+		{
+			if (this->m_Q[i].net().time() > mt)
+				mt = this->m_Q[i].net().time();
+		}
+
+		for (int i=0; i<7; i++)
+			m_Q[i].net().set_Q_time( tab7448[m_state][i], mt + NLTIME_FROM_NS(100));
+	}
+}
+
+ATTR_HOT void NETLIB_NAME(7448_sub)::dec_active()
+{
+	nl_assert(netlist().use_deactivate());
+	if (--m_active == 0)
+	{
+		m_A.inactivate();
+		m_B.inactivate();
+		m_C.inactivate();
+		m_D.inactivate();
+		m_RBIQ.inactivate();
+	}
+}
+#endif
+
 NETLIB_FUNC_VOID(7448_sub, update_outputs, (UINT8 v))
 {
 	nl_assert(v<16);
@@ -105,13 +200,8 @@ NETLIB_FUNC_VOID(7448_sub, update_outputs, (UINT8 v))
 	{
 		// max transfer time is 100 NS */
 
-		OUTLOGIC(m_a, tab7448[v][0], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_b, tab7448[v][1], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_c, tab7448[v][2], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_d, tab7448[v][3], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_e, tab7448[v][4], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_f, tab7448[v][5], NLTIME_FROM_NS(100));
-		OUTLOGIC(m_g, tab7448[v][6], NLTIME_FROM_NS(100));
+		for (int i=0; i<7; i++)
+			OUTLOGIC(m_Q[i], tab7448[v][i], NLTIME_FROM_NS(100));
 		m_state = v;
 	}
 }
@@ -136,7 +226,6 @@ const UINT8 NETLIB_NAME(7448_sub)::tab7448[16][7] =
 		{   0, 0, 0, 0, 0, 0, 0 },  /* 15 */
 };
 
-
 NETLIB_START(7448_dip)
 {
 	NETLIB_NAME(7448)::start();
@@ -149,15 +238,17 @@ NETLIB_START(7448_dip)
 	register_subalias("6", sub.m_D);
 	register_subalias("7", sub.m_A);
 
-	register_subalias("9", sub.m_e);
-	register_subalias("10", sub.m_d);
-	register_subalias("11", sub.m_c);
-	register_subalias("12", sub.m_b);
-	register_subalias("13", sub.m_a);
-	register_subalias("14", sub.m_g);
-	register_subalias("15", sub.m_f);
+	register_subalias("9",  sub.m_Q[4]); // e
+	register_subalias("10", sub.m_Q[3]); // d
+	register_subalias("11", sub.m_Q[2]); // c
+	register_subalias("12", sub.m_Q[1]); // b
+	register_subalias("13", sub.m_Q[0]); // a
+	register_subalias("14", sub.m_Q[6]); // g
+	register_subalias("15", sub.m_Q[5]); // f
 }
 
+#endif
+
 NETLIB_UPDATE(7448_dip)
 {
 	NETLIB_NAME(7448)::update();
diff --git a/src/emu/netlist/devices/nld_7448.h b/src/emu/netlist/devices/nld_7448.h
index 72aed7fa6f1..149b7ad8143 100644
--- a/src/emu/netlist/devices/nld_7448.h
+++ b/src/emu/netlist/devices/nld_7448.h
@@ -39,6 +39,19 @@
 #define TTL_7448_DIP(_name)                                                         \
 		NET_REGISTER_DEV(7448_dip, _name)
 
+/*
+ * FIXME: Big FIXME
+ * The truthtable will ignore BIQ for certain states.
+ * This causes a severe issue in pongf when USE_DEACTIVATE is used.
+ * For now, just use the old implementation.
+ *
+ */
+#if (0 && USE_TRUTHTABLE)
+#include "nld_truthtable.h"
+
+NETLIB_TRUTHTABLE(7448, 7, 7, 0);
+#else
+
 NETLIB_SUBDEVICE(7448_sub,
 	ATTR_HOT void update_outputs(UINT8 v);
 	static const UINT8 tab7448[16][7];
@@ -50,14 +63,15 @@ NETLIB_SUBDEVICE(7448_sub,
 	netlist_logic_input_t m_RBIQ;
 
 	UINT8 m_state;
+	int m_active;
 
-	netlist_logic_output_t m_a;
-	netlist_logic_output_t m_b;
-	netlist_logic_output_t m_c;
-	netlist_logic_output_t m_d;
-	netlist_logic_output_t m_e;
-	netlist_logic_output_t m_f;
-	netlist_logic_output_t m_g;
+	netlist_logic_output_t m_Q[7];  /* a .. g */
+
+	// FIXME: doesn't work
+#if 0
+	ATTR_HOT void inc_active();
+	ATTR_HOT void dec_active();
+#endif
 );
 
 NETLIB_DEVICE(7448,
@@ -67,7 +81,7 @@ public:
 	netlist_logic_input_t m_LTQ;
 	netlist_logic_input_t m_BIQ;
 );
-
+#endif
 NETLIB_DEVICE_DERIVED(7448_dip, 7448,
 );
 
diff --git a/src/emu/netlist/devices/nld_7474.c b/src/emu/netlist/devices/nld_7474.c
index 8795d83d927..1075a3a6288 100644
--- a/src/emu/netlist/devices/nld_7474.c
+++ b/src/emu/netlist/devices/nld_7474.c
@@ -10,7 +10,7 @@
 ATTR_HOT inline void NETLIB_NAME(7474sub)::newstate(const UINT8 stateQ, const UINT8 stateQQ)
 {
 	// 0: High-to-low 40 ns, 1: Low-to-high 25 ns
-	static const netlist_time delay[2] = { NLTIME_FROM_NS(40), NLTIME_FROM_NS(25) };
+	const netlist_time delay[2] = { NLTIME_FROM_NS(40), NLTIME_FROM_NS(25) };
 	OUTLOGIC(m_Q, stateQ, delay[stateQ]);
 	OUTLOGIC(m_QQ, stateQQ, delay[stateQQ]);
 }
diff --git a/src/emu/netlist/devices/nld_7486.c b/src/emu/netlist/devices/nld_7486.c
index b6c32b78287..2abbb5e42ce 100644
--- a/src/emu/netlist/devices/nld_7486.c
+++ b/src/emu/netlist/devices/nld_7486.c
@@ -12,16 +12,19 @@ NETLIB_START(7486)
 	register_input("A", m_A);
 	register_input("B", m_B);
 	register_output("Q", m_Q);
+
+	save(NLNAME(m_active));
 }
 
 NETLIB_RESET(7486)
 {
+	m_active = 1;
 }
 
-static const netlist_time delay[2] = { NLTIME_FROM_NS(15), NLTIME_FROM_NS(22) };
-
 NETLIB_UPDATE(7486)
 {
+	const netlist_time delay[2] = { NLTIME_FROM_NS(15), NLTIME_FROM_NS(22) };
+
 	UINT8 t = INPLOGIC(m_A) ^ INPLOGIC(m_B);
 	OUTLOGIC(m_Q, t, delay[t]);
 }
@@ -66,3 +69,31 @@ NETLIB_RESET(7486_dip)
 	m_3.do_reset();
 	m_4.do_reset();
 }
+
+ATTR_HOT void NETLIB_NAME(7486)::inc_active()
+{
+	const netlist_time delay[2] = { NLTIME_FROM_NS(15), NLTIME_FROM_NS(22) };
+	nl_assert(netlist().use_deactivate());
+	if (++m_active == 1)
+	{
+		netlist_time mt = this->m_A.net().time();
+		if (this->m_B.net().time() > mt)
+			mt = this->m_B.net().time();
+
+		m_A.activate();
+		m_B.activate();
+
+		UINT8 t = INPLOGIC(m_A) ^ INPLOGIC(m_B);
+		m_Q.net().set_Q_time(t, mt + delay[t]);
+	}
+}
+
+ATTR_HOT void NETLIB_NAME(7486)::dec_active()
+{
+	nl_assert(netlist().use_deactivate());
+	if (--m_active == 0)
+	{
+		m_A.inactivate();
+		m_B.inactivate();
+	}
+}
diff --git a/src/emu/netlist/devices/nld_7486.h b/src/emu/netlist/devices/nld_7486.h
index 6037c46bff1..5febda494f9 100644
--- a/src/emu/netlist/devices/nld_7486.h
+++ b/src/emu/netlist/devices/nld_7486.h
@@ -44,6 +44,10 @@ public:
 		netlist_logic_input_t m_A;
 		netlist_logic_input_t m_B;
 		netlist_logic_output_t m_Q;
+
+		ATTR_HOT void inc_active();
+		ATTR_HOT void dec_active();
+		int m_active;
 );
 
 #define TTL_7486_DIP(_name)                                                         \
diff --git a/src/emu/netlist/devices/nld_truthtable.c b/src/emu/netlist/devices/nld_truthtable.c
index 54733eb160f..8a90229da37 100644
--- a/src/emu/netlist/devices/nld_truthtable.c
+++ b/src/emu/netlist/devices/nld_truthtable.c
@@ -86,7 +86,7 @@ ATTR_COLD void truthtable_desc_t::setup(const char **truthtable)
 	truthtable++;
 
 	for (int j=0; j < m_size; j++)
-		m_outs[j] = -1;
+		m_outs[j] = 0; //-1;
 
 	for (int j=0; j < 16; j++)
 		m_timing_nt[j] = netlist_time::zero;
@@ -128,11 +128,11 @@ ATTR_COLD void truthtable_desc_t::setup(const char **truthtable)
 	// determine ignore
 	UINT32 ign[m_size];
 
-	for (int i=0; i<m_size; i++)
+	for (UINT32 i=0; i<m_size; i++)
 	{
 #if 1
 		UINT32 m_enable = 0;
-		for (int j=0; j<m_size; j++)
+		for (UINT32 j=0; j<m_size; j++)
 		{
 			if (m_outs[j] != m_outs[i])
 			{
diff --git a/src/emu/netlist/devices/nld_truthtable.h b/src/emu/netlist/devices/nld_truthtable.h
index ad2683f4f74..06a9971e17f 100644
--- a/src/emu/netlist/devices/nld_truthtable.h
+++ b/src/emu/netlist/devices/nld_truthtable.h
@@ -59,8 +59,8 @@ private:
 
 	/* additional values */
 
-	const int m_num_bits;
-	const int m_size;
+	const UINT32 m_num_bits;
+	const UINT32 m_size;
 
 };
 
@@ -154,16 +154,13 @@ public:
 		{
 			if (!doOUT || (m_ign & (1<<i)) != 0)
 				m_i[i].activate();
-			state |= (INPLOGIC(m_i[i]) << i);
 		}
-
-		if (!doOUT)
+		for (int i = 0; i < m_NI; i++)
 		{
-			for (int i = 0; i< m_NI; i++)
-			{
+			state |= (INPLOGIC(m_i[i]) << i);
+			if (!doOUT)
 				if (this->m_i[i].net().time() > mt)
 					mt = this->m_i[i].net().time();
-			}
 		}
 
 		const UINT32 nstate = state | (has_state ? (m_last_state << m_NI) : 0);