diff --git a/.gitattributes b/.gitattributes
index 54a0d8d8138..7d6c113a2d3 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2121,6 +2121,8 @@ src/emu/netlist/devices/nld_7400.h svneol=native#text/plain
 src/emu/netlist/devices/nld_7402.h svneol=native#text/plain
 src/emu/netlist/devices/nld_7410.h svneol=native#text/plain
 src/emu/netlist/devices/nld_7420.h svneol=native#text/plain
+src/emu/netlist/devices/nld_7425.h svneol=native#text/plain
+src/emu/netlist/devices/nld_7427.h svneol=native#text/plain
 src/emu/netlist/devices/nld_signal.h svneol=native#text/plain
 src/emu/netlist/devices/nld_system.h svneol=native#text/plain
 src/emu/netlist/netlist.mak svneol=native#text/plain
diff --git a/src/emu/machine/netlist.h b/src/emu/machine/netlist.h
index dde09639b5f..1b15bbf8856 100644
--- a/src/emu/machine/netlist.h
+++ b/src/emu/machine/netlist.h
@@ -95,7 +95,8 @@ private:
 // ======================> netlist_mame_device
 
 class netlist_mame_device : public device_t,
-						public device_execute_interface
+						    public device_execute_interface
+						    //, public device_memory_interface
 {
 public:
 
diff --git a/src/emu/netlist/devices/net_lib.c b/src/emu/netlist/devices/net_lib.c
index 948cbbc060a..6df4acacb4e 100644
--- a/src/emu/netlist/devices/net_lib.c
+++ b/src/emu/netlist/devices/net_lib.c
@@ -986,9 +986,9 @@ static const net_device_t_base_factory *netregistry[] =
 	ENTRY(7402,                 TTL_7402_NOR)
 	ENTRY(nic7404,              TTL_7404_INVERT)
 	ENTRY(7410,                 TTL_7410_NAND)
-	ENTRY(nic7420,              TTL_7420_NAND)
-	ENTRY(nic7425,              TTL_7425_NOR)
-	ENTRY(nic7427,              TTL_7427_NOR)
+	ENTRY(7420,                 TTL_7420_NAND)
+	ENTRY(7425,                 TTL_7425_NOR)
+	ENTRY(7427,                 TTL_7427_NOR)
 	ENTRY(nic7430,              TTL_7430_NAND)
 	ENTRY(nic7450,              TTL_7450_ANDORINVERT)
 	ENTRY(nic7486,              TTL_7486_XOR)
diff --git a/src/emu/netlist/devices/net_lib.h b/src/emu/netlist/devices/net_lib.h
index 03a43f52939..5bf8e016dbc 100644
--- a/src/emu/netlist/devices/net_lib.h
+++ b/src/emu/netlist/devices/net_lib.h
@@ -58,6 +58,8 @@
 #include "nld_7402.h"
 #include "nld_7410.h"
 #include "nld_7420.h"
+#include "nld_7425.h"
+#include "nld_7427.h"
 
 // this is a bad hack
 #define USE_OLD7493 (0)
@@ -105,18 +107,7 @@
 		NET_REGISTER_DEV(nic7404, _name)                                            \
 		NET_CONNECT(_name, I1, _I1)
 
-#define TTL_7425_NOR(_name, _I1, _I2, _I3, _I4)                                     \
-		NET_REGISTER_DEV(nic7425, _name)                                            \
-		NET_CONNECT(_name, A, _I1)                                                  \
-		NET_CONNECT(_name, B, _I2)                                                  \
-		NET_CONNECT(_name, C, _I3)                                                  \
-		NET_CONNECT(_name, D, _I4)
 
-#define TTL_7427_NOR(_name, _I1, _I2, _I3)                                          \
-		NET_REGISTER_DEV(nic7427, _name)                                            \
-		NET_CONNECT(_name, A, _I1)                                                  \
-		NET_CONNECT(_name, B, _I2)                                                  \
-		NET_CONNECT(_name, C, _I3)
 
 #define TTL_7430_NAND(_name, _I1, _I2, _I3, _I4, _I5, _I6, _I7, _I8)                \
 		NET_REGISTER_DEV(nic7430, _name)                                            \
@@ -312,8 +303,6 @@ NETLIB_DEVICE_WITH_PARAMS(nicNE555N_MSTABLE,
 	net_param_t m_VL;
 );
 
-NETLIB_SIGNAL(nic7425, 4, 1, 0);
-NETLIB_SIGNAL(nic7427, 3, 1, 0);
 NETLIB_SIGNAL(nic7430, 8, 0, 0);
 
 NETLIB_DEVICE(nic7404,
diff --git a/src/emu/netlist/devices/nld_7420.h b/src/emu/netlist/devices/nld_7420.h
index a771fed9276..8e21d1cdd1b 100644
--- a/src/emu/netlist/devices/nld_7420.h
+++ b/src/emu/netlist/devices/nld_7420.h
@@ -37,13 +37,13 @@
 #define NLD_7420_H_
 
 #define TTL_7420_NAND(_name, _I1, _I2, _I3, _I4)                                    \
-        NET_REGISTER_DEV(nic7420, _name)                                            \
+        NET_REGISTER_DEV(7420, _name)                                               \
         NET_CONNECT(_name, A, _I1)                                                  \
         NET_CONNECT(_name, B, _I2)                                                  \
         NET_CONNECT(_name, C, _I3)                                                  \
         NET_CONNECT(_name, D, _I4)
 
 
-NETLIB_SIGNAL(nic7420, 4, 0, 0);
+NETLIB_SIGNAL(7420, 4, 0, 0);
 
 #endif /* NLD_7420_H_ */
diff --git a/src/emu/netlist/devices/nld_7425.h b/src/emu/netlist/devices/nld_7425.h
new file mode 100644
index 00000000000..16fc1cadbb6
--- /dev/null
+++ b/src/emu/netlist/devices/nld_7425.h
@@ -0,0 +1,52 @@
+// license:GPL-2.0+
+// copyright-holders:Couriersud
+/*
+ * nld_7425.h
+ *
+ *  DM7425: Dual 4-Input NOR Gates
+ *
+ *          +--------------+
+ *       A1 |1     ++    14| VCC
+ *       B1 |2           13| D2
+ *       X1 |3           12| C2
+ *       C1 |4    7425   11| X2
+ *       D1 |5           10| B2
+ *       Y! |6            9| A2
+ *      GND |7            8| Y2
+ *          +--------------+
+ *                  _______
+ *              Y = A+B+C+D
+ *          +---+---+---+---+---++---+
+ *          | A | B | C | D | X || Y |
+ *          +===+===+===+===+===++===+
+ *          | X | X | X | X | 0 || Z |
+ *          | 0 | 0 | 0 | 0 | 1 || 1 |
+ *          | X | X | X | 1 | 1 || 0 |
+ *          | X | X | 1 | X | 1 || 0 |
+ *          | X | 1 | X | X | 1 || 0 |
+ *          | 1 | X | X | X | 1 || 0 |
+ *          +---+---+---+---+---++---+
+ *
+ *  TODO: The "X" input and high impedance output are currently not simulated.
+ *
+ *  Naming conventions follow National Semiconductor datasheet
+ *
+ */
+
+
+#include "nld_signal.h"
+
+#ifndef NLD_7425_H_
+#define NLD_7425_H_
+
+#define TTL_7425_NOR(_name, _I1, _I2, _I3, _I4)                                     \
+        NET_REGISTER_DEV(7425, _name)                                               \
+        NET_CONNECT(_name, A, _I1)                                                  \
+        NET_CONNECT(_name, B, _I2)                                                  \
+        NET_CONNECT(_name, C, _I3)                                                  \
+        NET_CONNECT(_name, D, _I4)
+
+
+NETLIB_SIGNAL(7425, 4, 1, 0);
+
+#endif /* NLD_7425_H_ */
diff --git a/src/emu/netlist/devices/nld_7427.h b/src/emu/netlist/devices/nld_7427.h
new file mode 100644
index 00000000000..00a8c0eec1c
--- /dev/null
+++ b/src/emu/netlist/devices/nld_7427.h
@@ -0,0 +1,46 @@
+// license:GPL-2.0+
+// copyright-holders:Couriersud
+/*
+ * nld_7427.h
+ *
+ *  DM7427: Triple 3-Input NOR Gates
+ *
+ *          +--------------+
+ *       A1 |1     ++    14| VCC
+ *       B1 |2           13| C1
+ *       A2 |3           12| Y1
+ *       B2 |4    7427   11| C3
+ *       C2 |5           10| B3
+ *       Y2 |6            9| A3
+ *      GND |7            8| Y3
+ *          +--------------+
+ *                  _____
+ *              Y = A+B+C
+ *          +---+---+---++---+
+ *          | A | B | C || Y |
+ *          +===+===+===++===+
+ *          | X | X | 1 || 0 |
+ *          | X | 1 | X || 0 |
+ *          | 1 | X | X || 0 |
+ *          | 0 | 0 | 0 || 1 |
+ *          +---+---+---++---+
+ *
+ *  Naming conventions follow National Semiconductor datasheet
+ *
+ */
+
+
+#include "nld_signal.h"
+
+#ifndef NLD_7427_H_
+#define NLD_7427_H_
+
+#define TTL_7427_NOR(_name, _I1, _I2, _I3)                                          \
+        NET_REGISTER_DEV(7427, _name)                                               \
+        NET_CONNECT(_name, A, _I1)                                                  \
+        NET_CONNECT(_name, B, _I2)                                                  \
+        NET_CONNECT(_name, C, _I3)
+
+NETLIB_SIGNAL(7427, 3, 1, 0);
+
+#endif /* NLD_7427_H_ */
diff --git a/src/emu/netlist/devices/nld_signal.h b/src/emu/netlist/devices/nld_signal.h
index 4265343f624..ab0a9faa362 100644
--- a/src/emu/netlist/devices/nld_signal.h
+++ b/src/emu/netlist/devices/nld_signal.h
@@ -191,7 +191,7 @@ public:
 
 	ATTR_HOT ATTR_ALIGN void update()
 	{
-		const netlist_time times[2] = { NLTIME_FROM_NS(22), NLTIME_FROM_NS(15) };
+		static const netlist_time times[2] = { NLTIME_FROM_NS(22), NLTIME_FROM_NS(15) };
 
 		int res = _invert ^ 1 ^_check;
 		m_i[0].activate();
diff --git a/src/emu/netlist/nl_base.c b/src/emu/netlist/nl_base.c
index c3e4539142c..6b66e7649bf 100644
--- a/src/emu/netlist/nl_base.c
+++ b/src/emu/netlist/nl_base.c
@@ -289,7 +289,10 @@ net_output_t::net_output_t(int atype)
 	//, m_new_Q(0)
 	//, m_Q_analog(0.0)
 	//, m_new_Q_analog(0.0)
-	, m_num_cons(0)
+#if USE_LINKED_LIST
+    , m_head(NULL)
+#endif
+    , m_num_cons(0)
 	, m_time(netlist_time::zero)
 	, m_active(0)
 	, m_in_queue(2)
@@ -322,6 +325,26 @@ ATTR_HOT inline void net_output_t::update_devs()
 
 	const UINT32 mask = masks[ (m_last.Q  << 1) | m_cur.Q ];
 
+#if USE_LINKED_LIST
+    net_input_t *p = m_head;
+    switch (m_num_cons)
+    {
+    case 2:
+        update_dev(p, mask);
+        p = p->m_next;
+    case 1:
+        update_dev(p, mask);
+        break;
+    default:
+        do
+        {
+            update_dev(p, mask);
+            p = p->m_next;
+        } while (p != NULL);
+        break;
+    }
+
+#else
 	switch (m_num_cons)
 	{
 	case 2:
@@ -336,16 +359,26 @@ ATTR_HOT inline void net_output_t::update_devs()
 		}
 		break;
 	}
-
+#endif
 	m_last = m_cur;
 }
 
 ATTR_COLD void net_output_t::register_con(net_input_t &input)
 {
-	int i;
+#if USE_LINKED_LIST
+    if (m_head == NULL)
+        m_head = &input;
+    else
+    {
+        input.m_next = m_head;
+        m_head = &input;
+    }
+#else
 	if (m_num_cons >= OUTPUT_MAX_CONNECTIONS)
 		fatalerror("Connections exceeded for %s\n", netdev()->name().cstr());
 
+#if 0
+    int i;
 	/* keep similar devices together */
 	for (i = 0; i < m_num_cons; i++)
 		if (m_cons[i]->netdev() == input.netdev())
@@ -355,9 +388,13 @@ ATTR_COLD void net_output_t::register_con(net_input_t &input)
 		m_cons[j] = m_cons[j - 1];
 
 	m_cons[i] = &input;
-	m_num_cons++;
-	if (input.state() != net_input_t::INP_STATE_PASSIVE)
-		m_active++;
+#else
+    m_cons[m_num_cons] = &input;
+#endif
+#endif
+    m_num_cons++;
+    if (input.state() != net_input_t::INP_STATE_PASSIVE)
+        m_active++;
 }
 
 // ----------------------------------------------------------------------------------------
diff --git a/src/emu/netlist/nl_base.h b/src/emu/netlist/nl_base.h
index 29ee006d8c8..710beb6f106 100644
--- a/src/emu/netlist/nl_base.h
+++ b/src/emu/netlist/nl_base.h
@@ -164,8 +164,11 @@ public:
 
 	ATTR_COLD net_input_t(const int atype)
 		: net_terminal_t(atype)
-		, m_low_thresh_V(0)
-		, m_high_thresh_V(0)
+        , m_low_thresh_V(0)
+        , m_high_thresh_V(0)
+#if USE_LINKED_LIST
+	    , m_next(NULL)
+#endif
 		, m_state(INP_STATE_ACTIVE)
 		, m_output(NULL)
 	{}
@@ -185,6 +188,10 @@ public:
 	double m_low_thresh_V;
 	double m_high_thresh_V;
 
+#if USE_LINKED_LIST
+	net_input_t *m_next;
+#endif
+
 private:
 	net_input_state m_state;
 	net_output_t * RESTRICT m_output;
@@ -248,9 +255,11 @@ class net_output_t : public net_terminal_t
 {
 public:
 
-    typedef struct {
-        double        Analog;
+    // FIXME: union does not work
+    typedef struct
+    {
         netlist_sig_t Q;
+        double        Analog;
     } hybrid_t;
 
 	net_output_t(int atype);
@@ -300,6 +309,9 @@ protected:
 	hybrid_t m_cur;
 	hybrid_t m_new;
 
+#if USE_LINKED_LIST
+	net_input_t *m_head;
+#endif
 	UINT32 m_num_cons;
 
 private:
@@ -311,7 +323,9 @@ private:
 
 	UINT32 m_in_queue;    /* 0: not in queue, 1: in queue, 2: last was taken */
 
+#if !USE_LINKED_LIST
 	net_input_t *  RESTRICT m_cons[OUTPUT_MAX_CONNECTIONS];
+#endif
 };
 
 
@@ -333,7 +347,7 @@ public:
 	{
 		if (EXPECTED(newQ != m_new.Q))
 		{
-			m_new.Q = newQ;
+	        m_new.Q = newQ;
 			if (m_num_cons)
 				push_to_queue(delay);
 		}
@@ -352,7 +366,9 @@ public:
 
 	ttl_output_t()
 		: logic_output_t()
-	{ set_levels(0.3, 3.4); }
+	{
+	    set_levels(0.3, 3.4);
+	}
 
 };
 
@@ -361,9 +377,17 @@ class analog_output_t : public net_output_t
 public:
 
 	analog_output_t()
-		: net_output_t(OUTPUT | SIGNAL_ANALOG) { }
+		: net_output_t(OUTPUT | SIGNAL_ANALOG)
+    {
+        m_cur.Analog = 0.0;
+        m_new.Analog = 0.0;
+    }
 
-    ATTR_COLD void initial(const double val) { m_cur.Analog = val; m_new.Analog = val; }
+    ATTR_COLD void initial(const double val)
+    {
+        m_cur.Analog = val;
+        m_new.Analog = val;
+    }
 
 	ATTR_HOT inline void set_Q(const double newQ, const netlist_time &delay)
 	{
diff --git a/src/emu/netlist/nl_config.h b/src/emu/netlist/nl_config.h
index fd729d5c217..efe7875a443 100644
--- a/src/emu/netlist/nl_config.h
+++ b/src/emu/netlist/nl_config.h
@@ -16,6 +16,8 @@
 //  SETUP
 //============================================================
 
+#define USE_LINKED_LIST         (1)
+
 #define USE_DELEGATES           (0)
 /*
  * The next options needs -Wno-pmf-conversions to compile and gcc