diff --git a/src/db/db/dbNetlistDeviceClasses.cc b/src/db/db/dbNetlistDeviceClasses.cc
index c2357fd58..f4dd10f60 100644
--- a/src/db/db/dbNetlistDeviceClasses.cc
+++ b/src/db/db/dbNetlistDeviceClasses.cc
@@ -96,8 +96,10 @@ bool DeviceClassTwoTerminalDevice::combine_devices (Device *a, Device *b) const
 //  DeviceClassResistor implementation
 
 DB_PUBLIC size_t DeviceClassResistor::param_id_R = 0;
-DB_PUBLIC size_t DeviceClassResistor::param_id_A = 1;
-DB_PUBLIC size_t DeviceClassResistor::param_id_P = 2;
+DB_PUBLIC size_t DeviceClassResistor::param_id_L = 1;
+DB_PUBLIC size_t DeviceClassResistor::param_id_W = 2;
+DB_PUBLIC size_t DeviceClassResistor::param_id_A = 3;
+DB_PUBLIC size_t DeviceClassResistor::param_id_P = 4;
 
 DB_PUBLIC size_t DeviceClassResistor::terminal_id_A = 0;
 DB_PUBLIC size_t DeviceClassResistor::terminal_id_B = 1;
@@ -108,6 +110,8 @@ DeviceClassResistor::DeviceClassResistor ()
   add_terminal_definition (db::DeviceTerminalDefinition ("B", "Terminal B"));
 
   add_parameter_definition (db::DeviceParameterDefinition ("R", "Resistance (Ohm)", 0.0));
+  add_parameter_definition (db::DeviceParameterDefinition ("L", "Length (micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("W", "Width (micrometer)", 0.0, false));
   add_parameter_definition (db::DeviceParameterDefinition ("A", "Area (square micrometer)", 0.0, false));
   add_parameter_definition (db::DeviceParameterDefinition ("P", "Perimeter (micrometer)", 0.0, false));
 }
@@ -118,15 +122,31 @@ void DeviceClassResistor::parallel (Device *a, Device *b) const
   double vb = b->parameter_value (0);
   a->set_parameter_value (0, va + vb < 1e-10 ? 0.0 : va * vb / (va + vb));
 
-  //  TODO: does this implementation make sense?
-  double aa = a->parameter_value (1);
-  double ab = b->parameter_value (1);
-  a->set_parameter_value (1, aa + ab);
+  //  parallel width is sum of both, length is the one that gives the same value of resistance
+  //    R = 1/(1/R1 + 1/R2)
+  //    R = L/(W1+W2)
+  //    R1 = L1/W1
+  //    R2 = L2/W2
+  //  -> L = (L1*L2*(W1+W2))/(L2*W1+L1*W2))
+  double l1 = a->parameter_value (1);
+  double w1 = a->parameter_value (2);
+  double l2 = b->parameter_value (1);
+  double w2 = b->parameter_value (2);
+  double dnom = (l2 * w1 + l1 * w2);
+  if (fabs (dnom) > 1e-15) {
+    a->set_parameter_value (1, (l1 * l2 * (w1 + w2)) / dnom);
+  }
+  a->set_parameter_value (2, w1 + w2);
 
-  //  TODO: does this implementation make sense?
-  double pa = a->parameter_value (2);
-  double pb = b->parameter_value (2);
-  a->set_parameter_value (2, pa + pb);
+  //  TODO: does this implementation make sense? (area)
+  double aa = a->parameter_value (3);
+  double ab = b->parameter_value (3);
+  a->set_parameter_value (3, aa + ab);
+
+  //  TODO: does this implementation make sense? (perimeter)
+  double pa = a->parameter_value (4);
+  double pb = b->parameter_value (4);
+  a->set_parameter_value (4, pa + pb);
 }
 
 void DeviceClassResistor::serial (Device *a, Device *b) const
@@ -135,13 +155,30 @@ void DeviceClassResistor::serial (Device *a, Device *b) const
   double vb = b->parameter_value (0);
   a->set_parameter_value (0, va + vb);
 
-  double aa = a->parameter_value (1);
-  double ab = b->parameter_value (1);
-  a->set_parameter_value (1, aa + ab);
+  //  parallel length is sum of both, width is the one that gives the same value of resistance
+  //  assuming same sheet rho
+  //    R = R1+R2
+  //    R = (L1+L2)/W
+  //    R1 = L1/W1
+  //    R2 = L2/W2
+  //  -> W = ((L1+L2)*W1*W2)/(W1*L2+W2*L1)
+  double l1 = a->parameter_value (1);
+  double w1 = a->parameter_value (2);
+  double l2 = b->parameter_value (1);
+  double w2 = b->parameter_value (2);
+  a->set_parameter_value (1, l1 + l2);
+  double dnom = (l2 * w1 + l1 * w2);
+  if (fabs (dnom) > 1e-15) {
+    a->set_parameter_value (2, (w1 * w2 * (l1 + l2)) / dnom);
+  }
 
-  double pa = a->parameter_value (2);
-  double pb = b->parameter_value (2);
-  a->set_parameter_value (2, pa + pb);
+  double aa = a->parameter_value (3);
+  double ab = b->parameter_value (3);
+  a->set_parameter_value (3, aa + ab);
+
+  double pa = a->parameter_value (4);
+  double pb = b->parameter_value (4);
+  a->set_parameter_value (4, pa + pb);
 }
 
 // ------------------------------------------------------------------------------------
@@ -288,8 +325,8 @@ DeviceClassDiode::DeviceClassDiode ()
   add_terminal_definition (db::DeviceTerminalDefinition ("A", "Anode"));
   add_terminal_definition (db::DeviceTerminalDefinition ("C", "Cathode"));
 
-  add_parameter_definition (db::DeviceParameterDefinition ("A", "Area (square micrometer)", 0.0));
-  add_parameter_definition (db::DeviceParameterDefinition ("P", "Perimeter (micrometer)", 0.0));
+  add_parameter_definition (db::DeviceParameterDefinition ("A", "Area (square micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("P", "Perimeter (micrometer)", 0.0, false));
 }
 
 bool DeviceClassDiode::combine_devices (Device *a, Device *b) const
@@ -438,16 +475,20 @@ bool DeviceClassMOS4Transistor::combine_devices (Device *a, Device *b) const
 }
 
 // ------------------------------------------------------------------------------------
-//  DeviceClassBipolarTransistor implementation
+//  DeviceClassBJT3Transistor implementation
 
-DB_PUBLIC size_t DeviceClassBipolarTransistor::param_id_AE = 0;
-DB_PUBLIC size_t DeviceClassBipolarTransistor::param_id_PE = 1;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_AE = 0;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_PE = 1;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_AB = 2;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_PB = 3;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_AC = 4;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::param_id_PC = 5;
 
-DB_PUBLIC size_t DeviceClassBipolarTransistor::terminal_id_C = 0;
-DB_PUBLIC size_t DeviceClassBipolarTransistor::terminal_id_B = 1;
-DB_PUBLIC size_t DeviceClassBipolarTransistor::terminal_id_E = 2;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::terminal_id_C = 0;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::terminal_id_B = 1;
+DB_PUBLIC size_t DeviceClassBJT3Transistor::terminal_id_E = 2;
 
-DeviceClassBipolarTransistor::DeviceClassBipolarTransistor ()
+DeviceClassBJT3Transistor::DeviceClassBJT3Transistor ()
 {
   add_terminal_definition (db::DeviceTerminalDefinition ("C", "Collector"));
   add_terminal_definition (db::DeviceTerminalDefinition ("B", "Base"));
@@ -455,9 +496,13 @@ DeviceClassBipolarTransistor::DeviceClassBipolarTransistor ()
 
   add_parameter_definition (db::DeviceParameterDefinition ("AE", "Emitter area (square micrometer)", 0.0, false));
   add_parameter_definition (db::DeviceParameterDefinition ("PE", "Emitter perimeter (micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("AB", "Base area (square micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("PB", "Base perimeter (micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("AC", "Collector area (square micrometer)", 0.0, false));
+  add_parameter_definition (db::DeviceParameterDefinition ("PC", "Collector perimeter (micrometer)", 0.0, false));
 }
 
-bool DeviceClassBipolarTransistor::combine_devices (Device *a, Device *b) const
+bool DeviceClassBJT3Transistor::combine_devices (Device *a, Device *b) const
 {
   const db::Net *nac = a->net_for_terminal (0);
   const db::Net *nab = a->net_for_terminal (1);
@@ -482,10 +527,34 @@ bool DeviceClassBipolarTransistor::combine_devices (Device *a, Device *b) const
   return false;
 }
 
-void DeviceClassBipolarTransistor::combine_parameters (Device *a, Device *b) const
+void DeviceClassBJT3Transistor::combine_parameters (Device *a, Device *b) const
 {
-  a->set_parameter_value (0, a->parameter_value (0) + b->parameter_value (0));
-  a->set_parameter_value (1, a->parameter_value (1) + b->parameter_value (1));
+  for (size_t i = 0; i < 6; ++i) {
+    a->set_parameter_value (i, a->parameter_value (i) + b->parameter_value (i));
+  }
+}
+
+// ------------------------------------------------------------------------------------
+//  DeviceClassBJT4Transistor implementation
+
+DB_PUBLIC size_t DeviceClassBJT4Transistor::terminal_id_S = 3;
+
+DeviceClassBJT4Transistor::DeviceClassBJT4Transistor ()
+{
+  add_terminal_definition (db::DeviceTerminalDefinition ("S", "Substrate"));
+}
+
+bool DeviceClassBJT4Transistor::combine_devices (Device *a, Device *b) const
+{
+  const db::Net *nas = a->net_for_terminal (3);
+  const db::Net *nbs = b->net_for_terminal (3);
+
+  //  combination is possible only if the substrate nets are the same
+  if (nas == nbs) {
+    return combine_devices (a, b);
+  } else {
+    return false;
+  }
 }
 
 }
diff --git a/src/db/db/dbNetlistDeviceClasses.h b/src/db/db/dbNetlistDeviceClasses.h
index 439ec7039..14bd51526 100644
--- a/src/db/db/dbNetlistDeviceClasses.h
+++ b/src/db/db/dbNetlistDeviceClasses.h
@@ -61,6 +61,8 @@ public:
   }
 
   static size_t param_id_R;
+  static size_t param_id_L;
+  static size_t param_id_W;
   static size_t param_id_A;
   static size_t param_id_P;
 
@@ -279,14 +281,18 @@ public:
  *  in micrometers.
  *  The bipolar transistor defines three terminals, "C", "B" and "E" for collector, base and emitter.
  */
-class DB_PUBLIC DeviceClassBipolarTransistor
+class DB_PUBLIC DeviceClassBJT3Transistor
   : public db::DeviceClass
 {
 public:
-  DeviceClassBipolarTransistor ();
+  DeviceClassBJT3Transistor ();
 
   static size_t param_id_AE;
   static size_t param_id_PE;
+  static size_t param_id_AB;
+  static size_t param_id_PB;
+  static size_t param_id_AC;
+  static size_t param_id_PC;
 
   static size_t terminal_id_C;
   static size_t terminal_id_B;
@@ -294,7 +300,7 @@ public:
 
   virtual db::DeviceClass *clone () const
   {
-    return new DeviceClassBipolarTransistor (*this);
+    return new DeviceClassBJT3Transistor (*this);
   }
 
   virtual bool combine_devices (Device *a, Device *b) const;
@@ -304,6 +310,27 @@ protected:
   void combine_parameters (Device *a, Device *b) const;
 };
 
+/**
+ *  @brief A basic bipolar transistor class with four terminals
+ *  The four-terminal BJT behaves identical to the three-terminal one but adds one more
+ *  terminal for the substrate.
+ */
+class DB_PUBLIC DeviceClassBJT4Transistor
+  : public DeviceClassBJT3Transistor
+{
+public:
+  DeviceClassBJT4Transistor ();
+
+  static size_t terminal_id_S;
+
+  virtual db::DeviceClass *clone () const
+  {
+    return new DeviceClassBJT4Transistor (*this);
+  }
+
+  virtual bool combine_devices (Device *a, Device *b) const;
+};
+
 }
 
 #endif
diff --git a/src/db/db/dbNetlistDeviceExtractorClasses.cc b/src/db/db/dbNetlistDeviceExtractorClasses.cc
index ef114cbb6..4a4b33296 100644
--- a/src/db/db/dbNetlistDeviceExtractorClasses.cc
+++ b/src/db/db/dbNetlistDeviceExtractorClasses.cc
@@ -262,6 +262,8 @@ void NetlistDeviceExtractorResistor::extract_devices (const std::vector<db::Regi
     }
 
     device->set_parameter_value (db::DeviceClassResistor::param_id_R, m_sheet_rho * double (length) / double (width));
+    device->set_parameter_value (db::DeviceClassResistor::param_id_L, dbu () * length);
+    device->set_parameter_value (db::DeviceClassResistor::param_id_W, dbu () * width);
     device->set_parameter_value (db::DeviceClassResistor::param_id_A, dbu () * dbu () * p->area ());
     device->set_parameter_value (db::DeviceClassResistor::param_id_P, dbu () * p->perimeter ());
 
@@ -410,15 +412,15 @@ void NetlistDeviceExtractorCapacitorWithBulk::modify_device (const db::Polygon &
 }
 
 // ---------------------------------------------------------------------------------
-//  NetlistDeviceExtractorBipolarTransistor implementation
+//  NetlistDeviceExtractorBJT3Transistor implementation
 
-NetlistDeviceExtractorBipolarTransistor::NetlistDeviceExtractorBipolarTransistor (const std::string &name)
+NetlistDeviceExtractorBJT3Transistor::NetlistDeviceExtractorBJT3Transistor (const std::string &name)
   : db::NetlistDeviceExtractor (name)
 {
   //  .. nothing yet ..
 }
 
-void NetlistDeviceExtractorBipolarTransistor::setup ()
+void NetlistDeviceExtractorBJT3Transistor::setup ()
 {
   define_layer ("C", "Collector");                                      // #0
   define_layer ("B", "Base");                                           // #1
@@ -429,10 +431,10 @@ void NetlistDeviceExtractorBipolarTransistor::setup ()
   define_layer ("tB", 1, "Base terminal output");                       // #4 -> B
   define_layer ("tE", 2, "Emitter terminal output");                    // #5 -> E
 
-  register_device_class (new db::DeviceClassBipolarTransistor ());
+  register_device_class (new db::DeviceClassBJT3Transistor ());
 }
 
-db::Connectivity NetlistDeviceExtractorBipolarTransistor::get_connectivity (const db::Layout & /*layout*/, const std::vector<unsigned int> &layers) const
+db::Connectivity NetlistDeviceExtractorBJT3Transistor::get_connectivity (const db::Layout & /*layout*/, const std::vector<unsigned int> &layers) const
 {
   tl_assert (layers.size () >= 3);
 
@@ -449,7 +451,7 @@ db::Connectivity NetlistDeviceExtractorBipolarTransistor::get_connectivity (cons
   return conn;
 }
 
-void NetlistDeviceExtractorBipolarTransistor::extract_devices (const std::vector<db::Region> &layer_geometry)
+void NetlistDeviceExtractorBJT3Transistor::extract_devices (const std::vector<db::Region> &layer_geometry)
 {
   unsigned int collector_geometry_index = 0;
   unsigned int base_geometry_index = 1;
@@ -478,18 +480,30 @@ void NetlistDeviceExtractorBipolarTransistor::extract_devices (const std::vector
       error (tl::to_string (tr ("Base shape without emitters - ignored")), *p);
     } else {
 
+      double ab = dbu () * dbu () * p->area ();
+      double pb = dbu () * p->perimeter ();
+
+      double ac = dbu () * dbu () * rcollector2base.area ();
+      double pc = dbu () * rcollector2base.perimeter ();
+
       for (db::Region::const_iterator pe = remitter2base.begin_merged (); !pe.at_end (); ++pe) {
 
         db::Device *device = create_device ();
 
         device->set_trans (db::DCplxTrans ((pe->box ().center () - db::Point ()) * dbu ()));
 
-        device->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_AE, dbu () * dbu () * pe->area ());
-        device->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_PE, dbu () * pe->perimeter ());
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AE, dbu () * dbu () * pe->area ());
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PE, dbu () * pe->perimeter ());
 
-        define_terminal (device, db::DeviceClassBipolarTransistor::terminal_id_C, collector_terminal_geometry_index, rcollector2base);
-        define_terminal (device, db::DeviceClassBipolarTransistor::terminal_id_B, base_terminal_geometry_index, *p);
-        define_terminal (device, db::DeviceClassBipolarTransistor::terminal_id_E, emitter_terminal_geometry_index, *pe);
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AB, ab);
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PB, pb);
+
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AC, ac);
+        device->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PC, pc);
+
+        define_terminal (device, db::DeviceClassBJT3Transistor::terminal_id_C, collector_terminal_geometry_index, rcollector2base);
+        define_terminal (device, db::DeviceClassBJT3Transistor::terminal_id_B, base_terminal_geometry_index, *p);
+        define_terminal (device, db::DeviceClassBJT3Transistor::terminal_id_E, emitter_terminal_geometry_index, *pe);
 
         //  allow derived classes to modify the device
         modify_device (*p, layer_geometry, device);
@@ -504,6 +518,40 @@ void NetlistDeviceExtractorBipolarTransistor::extract_devices (const std::vector
   }
 }
 
+// ---------------------------------------------------------------------------------
+//  NetlistDeviceExtractorBJT4Transistor implementation
+
+NetlistDeviceExtractorBJT4Transistor::NetlistDeviceExtractorBJT4Transistor (const std::string &name)
+  : NetlistDeviceExtractorBJT3Transistor (name)
+{
+  //  .. nothing yet ..
+}
+
+void NetlistDeviceExtractorBJT4Transistor::setup ()
+{
+  define_layer ("C", "Collector");                                      // #0
+  define_layer ("B", "Base");                                           // #1
+  define_layer ("E", "Emitter");                                        // #2
+
+  //  terminal output
+  define_layer ("tC", 0, "Collector terminal output");                  // #3 -> C
+  define_layer ("tB", 1, "Base terminal output");                       // #4 -> B
+  define_layer ("tE", 2, "Emitter terminal output");                    // #5 -> E
+
+  //  for convenience and consistency with MOS4
+  define_layer ("S", "Substrate (bulk) terminal output");               // #6
+
+  define_layer ("tS", 6, "Substrate (bulk) terminal output");           // #7 -> S
+
+  register_device_class (new db::DeviceClassBJT4Transistor ());
+}
+
+void NetlistDeviceExtractorBJT4Transistor::modify_device (const db::Polygon &emitter, const std::vector<db::Region> & /*layer_geometry*/, db::Device *device)
+{
+  unsigned int substrate_terminal_geometry_index = 7;
+  define_terminal (device, db::DeviceClassBJT4Transistor::terminal_id_S, substrate_terminal_geometry_index, emitter);
+}
+
 // ---------------------------------------------------------------------------------
 //  NetlistDeviceExtractorDiode implementation
 
diff --git a/src/db/db/dbNetlistDeviceExtractorClasses.h b/src/db/db/dbNetlistDeviceExtractorClasses.h
index 50ab9eef0..f4fc1ece6 100644
--- a/src/db/db/dbNetlistDeviceExtractorClasses.h
+++ b/src/db/db/dbNetlistDeviceExtractorClasses.h
@@ -242,17 +242,17 @@ public:
  *  region will be output to the 'tC' terminal output layer. This layer then needs to be connected to a global net
  *  to form the net connection.
  *
- *  The device class produced by this extractor is \\DeviceClassBipolarTransistor.
+ *  The device class produced by this extractor is \\DeviceClassBJT3Transistor.
  *  The extractor extracts the two parameters of this class: AE and PE.
  *
  *  The device recognition layer names are 'C' (collector), 'B' (base) and 'E' (emitter).
  *  The terminal output layer names are 'tC' (collector), 'tB' (base) and 'tE' (emitter).
  */
-class DB_PUBLIC NetlistDeviceExtractorBipolarTransistor
+class DB_PUBLIC NetlistDeviceExtractorBJT3Transistor
   : public db::NetlistDeviceExtractor
 {
 public:
-  NetlistDeviceExtractorBipolarTransistor (const std::string &name);
+  NetlistDeviceExtractorBJT3Transistor (const std::string &name);
 
   virtual void setup ();
   virtual db::Connectivity get_connectivity (const db::Layout &layout, const std::vector<unsigned int> &layers) const;
@@ -277,6 +277,26 @@ protected:
   }
 };
 
+/**
+ *  @brief A device extractor for a four-terminal BJT transistor
+ *
+ *  This class is like the BJT3Transistor extractor, but requires a forth
+ *  input layer (Substrate). This layer will be used to output the substrate terminal.
+ *
+ *  The device class produced by this extractor is DeviceClassBJT4Transistor.
+ */
+class DB_PUBLIC NetlistDeviceExtractorBJT4Transistor
+  : public NetlistDeviceExtractorBJT3Transistor
+{
+public:
+  NetlistDeviceExtractorBJT4Transistor (const std::string &name);
+
+  virtual void setup ();
+
+private:
+  virtual void modify_device (const db::Polygon &emitter, const std::vector<db::Region> &layer_geometry, db::Device *device);
+};
+
 /**
  *  @brief A device extractor for a planar diode
  *
@@ -363,7 +383,7 @@ template<> struct type_traits<db::NetlistDeviceExtractorResistorWithBulk> : publ
   typedef tl::false_tag has_default_constructor;
 };
 
-template<> struct type_traits<db::NetlistDeviceExtractorBipolarTransistor> : public tl::type_traits<void>
+template<> struct type_traits<db::NetlistDeviceExtractorBJT3Transistor> : public tl::type_traits<void>
 {
   typedef tl::false_tag has_copy_constructor;
   typedef tl::false_tag has_default_constructor;
diff --git a/src/db/db/dbNetlistSpiceWriter.cc b/src/db/db/dbNetlistSpiceWriter.cc
index 654855e49..935220609 100644
--- a/src/db/db/dbNetlistSpiceWriter.cc
+++ b/src/db/db/dbNetlistSpiceWriter.cc
@@ -97,6 +97,8 @@ void NetlistSpiceWriterDelegate::write_device (const db::Device &dev) const
   const db::DeviceClassDiode *diode = dynamic_cast<const db::DeviceClassDiode *> (dc);
   const db::DeviceClassMOS3Transistor *mos3 = dynamic_cast<const db::DeviceClassMOS3Transistor *> (dc);
   const db::DeviceClassMOS4Transistor *mos4 = dynamic_cast<const db::DeviceClassMOS4Transistor *> (dc);
+  const db::DeviceClassBJT3Transistor *bjt3 = dynamic_cast<const db::DeviceClassBJT3Transistor *> (dc);
+  const db::DeviceClassBJT3Transistor *bjt4 = dynamic_cast<const db::DeviceClassBJT4Transistor *> (dc);
 
   std::ostringstream os;
 
@@ -130,10 +132,13 @@ void NetlistSpiceWriterDelegate::write_device (const db::Device &dev) const
     os << format_name (dev.expanded_name ());
     os << format_terminals (dev);
 
-    //  Use "D" + device class name for the model
-    os << " D";
+    //  Use device class name for the model
+    os << " ";
     os << format_name (dev.device_class ()->name ());
 
+    os << " A=" << tl::sprintf ("%.12gP", dev.parameter_value (db::DeviceClassDiode::param_id_A));
+    os << " P=" << tl::sprintf ("%.12gP", dev.parameter_value (db::DeviceClassDiode::param_id_P));
+
   } else if (mos3 || mos4) {
 
     os << "M";
@@ -157,6 +162,23 @@ void NetlistSpiceWriterDelegate::write_device (const db::Device &dev) const
     os << " PS=" << tl::sprintf ("%.12gU", dev.parameter_value (db::DeviceClassMOS3Transistor::param_id_PS));
     os << " PD=" << tl::sprintf ("%.12gU", dev.parameter_value (db::DeviceClassMOS3Transistor::param_id_PD));
 
+  } else if (bjt3 || bjt4) {
+
+    os << "Q";
+    os << format_name (dev.expanded_name ());
+    os << format_terminals (dev);
+
+    //  Use device class name for the model
+    os << " ";
+    os << format_name (dev.device_class ()->name ());
+
+    os << " AE=" << tl::sprintf ("%.12gP", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_AE));
+    os << " AB=" << tl::sprintf ("%.12gP", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_AB));
+    os << " AC=" << tl::sprintf ("%.12gP", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_AC));
+    os << " PE=" << tl::sprintf ("%.12gU", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_PE));
+    os << " PB=" << tl::sprintf ("%.12gU", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_PB));
+    os << " PC=" << tl::sprintf ("%.12gU", dev.parameter_value (db::DeviceClassBJT3Transistor::param_id_PC));
+
   } else {
 
     //  Write unknown devices as subcircuits (CAUTION: potential name clash)
diff --git a/src/db/db/gsiDeclDbNetlistDeviceClasses.cc b/src/db/db/gsiDeclDbNetlistDeviceClasses.cc
index 58cb7f6ab..8281061ff 100644
--- a/src/db/db/gsiDeclDbNetlistDeviceClasses.cc
+++ b/src/db/db/gsiDeclDbNetlistDeviceClasses.cc
@@ -37,33 +37,40 @@ Class<db::DeviceClassResistor> decl_dbDeviceClassResistor (decl_dbDeviceClass, "
   ) +
   gsi::constant ("PARAM_R", db::DeviceClassResistor::param_id_R,
     "@brief A constant giving the parameter ID for parameter R"
+  ) +
+  gsi::constant ("PARAM_L", db::DeviceClassResistor::param_id_L,
+    "@brief A constant giving the parameter ID for parameter L"
+  ) +
+  gsi::constant ("PARAM_W", db::DeviceClassResistor::param_id_W,
+    "@brief A constant giving the parameter ID for parameter W"
+  ) +
+  gsi::constant ("PARAM_A", db::DeviceClassResistor::param_id_A,
+    "@brief A constant giving the parameter ID for parameter A"
+  ) +
+  gsi::constant ("PARAM_P", db::DeviceClassResistor::param_id_P,
+    "@brief A constant giving the parameter ID for parameter P"
   ),
   "@brief A device class for a resistor.\n"
   "This class describes a resistor. Resistors are defined by their combination behavior and "
   "the basic parameter 'R' which is the resistance in Ohm.\n"
   "\n"
   "A resistor has two terminals, A and B.\n"
+  "The parameters of a resistor are R (the value in Ohms), L and W (length and width in micrometers) and "
+  "A and P (area and perimeter in square micrometers and micrometers respectively).\n"
   "\n"
   "This class has been introduced in version 0.26."
 );
 
-Class<db::DeviceClassResistorWithBulk> decl_dbDeviceClassResistorWithBulk (decl_dbDeviceClass, "db", "DeviceClassResistorWithBulk",
-  gsi::constant ("TERMINAL_A", db::DeviceClassResistorWithBulk::terminal_id_A,
-    "@brief A constant giving the terminal ID for terminal A"
-  ) +
-  gsi::constant ("TERMINAL_B", db::DeviceClassResistorWithBulk::terminal_id_B,
-    "@brief A constant giving the terminal ID for terminal B"
-  ) +
+Class<db::DeviceClassResistorWithBulk> decl_dbDeviceClassResistorWithBulk (decl_dbDeviceClassResistor, "db", "DeviceClassResistorWithBulk",
   gsi::constant ("TERMINAL_W", db::DeviceClassResistorWithBulk::terminal_id_W,
     "@brief A constant giving the terminal ID for terminal W (well, bulk)"
-  ) +
-  gsi::constant ("PARAM_R", db::DeviceClassResistorWithBulk::param_id_R,
-    "@brief A constant giving the parameter ID for parameter R"
   ),
   "@brief A device class for a resistor with a bulk terminal (substrate, well).\n"
   "This class is similar to \\DeviceClassResistor, but provides an additional terminal (BULK) for the "
   "well or substrate the resistor is embedded in.\n"
   "\n"
+  "The additional terminal is 'W' for the well/substrate terminal.\n"
+  "\n"
   "This class has been introduced in version 0.26."
 );
 
@@ -76,33 +83,34 @@ Class<db::DeviceClassCapacitor> decl_dbDeviceClassCapacitor (decl_dbDeviceClass,
   ) +
   gsi::constant ("PARAM_C", db::DeviceClassCapacitor::param_id_C,
     "@brief A constant giving the parameter ID for parameter C"
+  ) +
+  gsi::constant ("PARAM_A", db::DeviceClassCapacitor::param_id_A,
+    "@brief A constant giving the parameter ID for parameter A"
+  ) +
+  gsi::constant ("PARAM_P", db::DeviceClassCapacitor::param_id_P,
+    "@brief A constant giving the parameter ID for parameter P"
   ),
   "@brief A device class for a capacitor.\n"
   "This describes a capacitor. Capacitors are defined by their combination behavior and "
   "the basic parameter 'C' which is the capacitance in Farad.\n"
   "\n"
   "A capacitor has two terminals, A and B.\n"
+  "The parameters of a capacitor are C (the value in Farad) and "
+  "A and P (area and perimeter in square micrometers and micrometers respectively).\n"
   "\n"
   "This class has been introduced in version 0.26."
 );
 
-Class<db::DeviceClassCapacitorWithBulk> decl_dbDeviceClassCapacitorWithBulk (decl_dbDeviceClass, "db", "DeviceClassCapacitorWithBulk",
-  gsi::constant ("TERMINAL_A", db::DeviceClassCapacitorWithBulk::terminal_id_A,
-    "@brief A constant giving the terminal ID for terminal A"
-  ) +
-  gsi::constant ("TERMINAL_B", db::DeviceClassCapacitorWithBulk::terminal_id_B,
-    "@brief A constant giving the terminal ID for terminal B"
-  ) +
+Class<db::DeviceClassCapacitorWithBulk> decl_dbDeviceClassCapacitorWithBulk (decl_dbDeviceClassCapacitor, "db", "DeviceClassCapacitorWithBulk",
   gsi::constant ("TERMINAL_W", db::DeviceClassCapacitorWithBulk::terminal_id_W,
     "@brief A constant giving the terminal ID for terminal W (well, bulk)"
-  ) +
-  gsi::constant ("PARAM_C", db::DeviceClassCapacitorWithBulk::param_id_C,
-    "@brief A constant giving the parameter ID for parameter C"
   ),
   "@brief A device class for a capacitor with a bulk terminal (substrate, well).\n"
   "This class is similar to \\DeviceClassCapacitor, but provides an additional terminal (BULK) for the "
   "well or substrate the capacitor is embedded in.\n"
   "\n"
+  "The additional terminal is 'W' for the well/substrate terminal.\n"
+  "\n"
   "This class has been introduced in version 0.26."
 );
 
@@ -148,26 +156,54 @@ Class<db::DeviceClassDiode> decl_dbDeviceClassDiode (decl_dbDeviceClass, "db", "
   "This class has been introduced in version 0.26."
 );
 
-Class<db::DeviceClassBipolarTransistor> decl_DeviceClassBipolarTransistor (decl_dbDeviceClass, "db", "DeviceClassBipolarTransistor",
-  gsi::constant ("TERMINAL_C", db::DeviceClassBipolarTransistor::terminal_id_C,
+Class<db::DeviceClassBJT3Transistor> decl_dbDeviceClassBJT3Transistor (decl_dbDeviceClass, "db", "DeviceClassBJT3Transistor",
+  gsi::constant ("TERMINAL_C", db::DeviceClassBJT3Transistor::terminal_id_C,
     "@brief A constant giving the terminal ID for terminal C (collector)"
   ) +
-  gsi::constant ("TERMINAL_B", db::DeviceClassBipolarTransistor::terminal_id_B,
+  gsi::constant ("TERMINAL_B", db::DeviceClassBJT3Transistor::terminal_id_B,
     "@brief A constant giving the terminal ID for terminal B (base)"
   ) +
-  gsi::constant ("TERMINAL_E", db::DeviceClassBipolarTransistor::terminal_id_E,
+  gsi::constant ("TERMINAL_E", db::DeviceClassBJT3Transistor::terminal_id_E,
     "@brief A constant giving the terminal ID for terminal E (emitter)"
   ) +
-  gsi::constant ("PARAM_AE", db::DeviceClassBipolarTransistor::param_id_AE,
+  gsi::constant ("PARAM_AE", db::DeviceClassBJT3Transistor::param_id_AE,
     "@brief A constant giving the parameter ID for parameter AE (emitter area)"
   ) +
-  gsi::constant ("PARAM_PE", db::DeviceClassBipolarTransistor::param_id_PE,
+  gsi::constant ("PARAM_PE", db::DeviceClassBJT3Transistor::param_id_PE,
     "@brief A constant giving the parameter ID for parameter PE (emitter perimeter)"
+  ) +
+  gsi::constant ("PARAM_AB", db::DeviceClassBJT3Transistor::param_id_AB,
+    "@brief A constant giving the parameter ID for parameter AB (base area)"
+  ) +
+  gsi::constant ("PARAM_PB", db::DeviceClassBJT3Transistor::param_id_PB,
+    "@brief A constant giving the parameter ID for parameter PB (base perimeter)"
+  ) +
+  gsi::constant ("PARAM_AC", db::DeviceClassBJT3Transistor::param_id_AC,
+    "@brief A constant giving the parameter ID for parameter AC (collector area)"
+  ) +
+  gsi::constant ("PARAM_PC", db::DeviceClassBJT3Transistor::param_id_PC,
+    "@brief A constant giving the parameter ID for parameter PC (collector perimeter)"
   ),
   "@brief A device class for a bipolar transistor.\n"
   "This class describes a bipolar transistor. Bipolar transistors have tree terminals: the collector (C), the base (B) and the emitter (E).\n"
-  "Multi-emitter transistors are resolved in individual devices. The basic parameter of a transistor is the emitter area (AE). "
-  "In addition, the emitter perimeter is extracted too (PE)."
+  "Multi-emitter transistors are resolved in individual devices."
+  "\n"
+  "The parameters are AE, AB and AC for the emitter, base and collector areas in square micrometers and "
+  "PE, PB and PC for the emitter, base and collector perimeters in micrometers.\n"
+  "\n"
+  "This class has been introduced in version 0.26."
+);
+
+Class<db::DeviceClassBJT4Transistor> decl_dbDeviceClassBJT4Transistor (decl_dbDeviceClassBJT3Transistor, "db", "DeviceClassBJT4Transistor",
+  gsi::constant ("TERMINAL_S", db::DeviceClassBJT4Transistor::terminal_id_S,
+    "@brief A constant giving the terminal ID for terminal S"
+  ),
+  "@brief A device class for a 4-terminal bipolar transistor.\n"
+  "This class describes a bipolar transistor with a substrate terminal. "
+  "A device class for a bipolar transistor without a substrate terminal is \\DeviceClassBJT3Transistor. "
+  "\n"
+  "The additional terminal is 'S' for the substrate terminal.\n"
+  "BJT4 transistors combine in parallel if both substrate terminals are connected to the same net.\n"
   "\n"
   "This class has been introduced in version 0.26."
 );
@@ -217,50 +253,17 @@ Class<db::DeviceClassMOS3Transistor> decl_dbDeviceClassMOS3Transistor (decl_dbDe
   "This class has been introduced in version 0.26."
 );
 
-Class<db::DeviceClassMOS4Transistor> decl_dbDeviceClassMOS4Transistor (decl_dbDeviceClass, "db", "DeviceClassMOS4Transistor",
-  gsi::constant ("TERMINAL_S", db::DeviceClassMOS4Transistor::terminal_id_S,
-    "@brief A constant giving the terminal ID for terminal S"
-  ) +
-  gsi::constant ("TERMINAL_D", db::DeviceClassMOS4Transistor::terminal_id_D,
-    "@brief A constant giving the terminal ID for terminal D"
-  ) +
-  gsi::constant ("TERMINAL_G", db::DeviceClassMOS4Transistor::terminal_id_G,
-    "@brief A constant giving the terminal ID for terminal G"
-  ) +
+Class<db::DeviceClassMOS4Transistor> decl_dbDeviceClassMOS4Transistor (decl_dbDeviceClassMOS3Transistor, "db", "DeviceClassMOS4Transistor",
   gsi::constant ("TERMINAL_B", db::DeviceClassMOS4Transistor::terminal_id_B,
     "@brief A constant giving the terminal ID for terminal B"
-  ) +
-  gsi::constant ("PARAM_L", db::DeviceClassMOS4Transistor::param_id_L,
-    "@brief A constant giving the parameter ID for parameter L"
-  ) +
-  gsi::constant ("PARAM_W", db::DeviceClassMOS4Transistor::param_id_W,
-    "@brief A constant giving the parameter ID for parameter W"
-  ) +
-  gsi::constant ("PARAM_AS", db::DeviceClassMOS4Transistor::param_id_AS,
-    "@brief A constant giving the parameter ID for parameter AS"
-  ) +
-  gsi::constant ("PARAM_AD", db::DeviceClassMOS4Transistor::param_id_AD,
-    "@brief A constant giving the parameter ID for parameter AD"
-  ) +
-  gsi::constant ("PARAM_PS", db::DeviceClassMOS4Transistor::param_id_PS,
-    "@brief A constant giving the parameter ID for parameter PS"
-  ) +
-  gsi::constant ("PARAM_PD", db::DeviceClassMOS4Transistor::param_id_PD,
-    "@brief A constant giving the parameter ID for parameter PD"
   ),
   "@brief A device class for a 4-terminal MOS transistor.\n"
   "This class describes a MOS transistor with a bulk terminal. "
   "A device class for a MOS transistor without a bulk terminal is \\DeviceClassMOS3Transistor. "
   "MOS transistors are defined by their combination behavior and the basic parameters.\n"
   "\n"
-  "The parameters are L, W, AS, AD, PS and PD for the gate length and width in micrometers, source and drain area "
-  "in square micrometers and the source and drain perimeter in micrometers.\n"
-  "\n"
-  "The terminals are S, G, D and B for source, gate, drain and bulk.\n"
-  "\n"
-  "MOS transistors combine in parallel mode, when both gate lengths are identical and "
-  "their gates and bulk terminals are connected (source and drain can be swapped). In this case, their widths and source and drain "
-  "areas are added.\n"
+  "The additional terminal is 'B' for the bulk terminal.\n"
+  "MOS4 transistors combine in parallel if both bulk terminals are connected to the same net.\n"
   "\n"
   "This class has been introduced in version 0.26."
 );
diff --git a/src/db/db/gsiDeclDbNetlistDeviceExtractor.cc b/src/db/db/gsiDeclDbNetlistDeviceExtractor.cc
index 40e759fbc..e1532187d 100644
--- a/src/db/db/gsiDeclDbNetlistDeviceExtractor.cc
+++ b/src/db/db/gsiDeclDbNetlistDeviceExtractor.cc
@@ -588,12 +588,12 @@ Class<db::NetlistDeviceExtractorCapacitorWithBulk> decl_NetlistDeviceExtractorCa
   "This class has been introduced in version 0.26."
 );
 
-db::NetlistDeviceExtractorBipolarTransistor *make_bjt_extractor (const std::string &name)
+db::NetlistDeviceExtractorBJT3Transistor *make_bjt_extractor (const std::string &name)
 {
-  return new db::NetlistDeviceExtractorBipolarTransistor (name);
+  return new db::NetlistDeviceExtractorBJT3Transistor (name);
 }
 
-Class<db::NetlistDeviceExtractorBipolarTransistor> decl_NetlistDeviceExtractorBipolarTransistor (decl_dbNetlistDeviceExtractor, "db", "DeviceExtractorBipolarTransistor",
+Class<db::NetlistDeviceExtractorBJT3Transistor> decl_NetlistDeviceExtractorBJT3Transistor (decl_dbNetlistDeviceExtractor, "db", "DeviceExtractorBJT3Transistor",
   gsi::constructor ("new", &make_bjt_extractor, gsi::arg ("name"),
     "@brief Creates a new device extractor with the given name."
   ),
@@ -610,7 +610,7 @@ Class<db::NetlistDeviceExtractorBipolarTransistor> decl_NetlistDeviceExtractorBi
   "region will be output to the 'tC' terminal output layer. This layer then needs to be connected to a global net "
   "to form the net connection.\n"
   "\n"
-  "The device class produced by this extractor is \\DeviceClassBipolarTransistor.\n"
+  "The device class produced by this extractor is \\DeviceClassBJT3Transistor.\n"
   "The extractor extracts the two parameters of this class: AE and PE.\n"
   "\n"
   "The device recognition layer names are 'C' (collector), 'B' (base) and 'E' (emitter).\n"
diff --git a/src/db/unit_tests/dbNetlistDeviceClassesTests.cc b/src/db/unit_tests/dbNetlistDeviceClassesTests.cc
index 5a97e9c71..83bf957bd 100644
--- a/src/db/unit_tests/dbNetlistDeviceClassesTests.cc
+++ b/src/db/unit_tests/dbNetlistDeviceClassesTests.cc
@@ -37,10 +37,14 @@ TEST(1_SerialResistors)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 1.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -70,8 +74,8 @@ TEST(1_SerialResistors)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -80,7 +84,7 @@ TEST(1_SerialResistors)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n1,B=n3) (R=4,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n3) (R=4,L=18,W=1.5,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -94,10 +98,14 @@ TEST(2_SerialResistors1Swapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 1.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -127,8 +135,8 @@ TEST(2_SerialResistors1Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n3,B=n2) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n3,B=n2) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -137,7 +145,7 @@ TEST(2_SerialResistors1Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n1,B=n3) (R=4,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n3) (R=4,L=18,W=1.5,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -151,10 +159,14 @@ TEST(3_SerialResistors1OtherSwapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 1.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -184,8 +196,8 @@ TEST(3_SerialResistors1OtherSwapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n2,B=n1) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n2,B=n1) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -194,7 +206,7 @@ TEST(3_SerialResistors1OtherSwapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n3,B=n1) (R=4,A=6,P=12);\n"
+    "  device '' r1 (A=n3,B=n1) (R=4,L=18,W=1.5,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -208,10 +220,14 @@ TEST(4_SerialResistors2Swapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 1.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -241,8 +257,8 @@ TEST(4_SerialResistors2Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n2,B=n1) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n3,B=n2) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n2,B=n1) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n3,B=n2) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -251,7 +267,7 @@ TEST(4_SerialResistors2Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3);\n"
-    "  device '' r1 (A=n3,B=n1) (R=4,A=6,P=12);\n"
+    "  device '' r1 (A=n3,B=n1) (R=4,L=18,W=1.5,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -265,10 +281,14 @@ TEST(5_SerialResistorsNoCombination)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 1.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -300,8 +320,8 @@ TEST(5_SerialResistorsNoCombination)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,C=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -310,8 +330,8 @@ TEST(5_SerialResistorsNoCombination)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,C=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 }
@@ -325,10 +345,14 @@ TEST(6_ParallelResistors)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 2.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -355,8 +379,8 @@ TEST(6_ParallelResistors)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n1,B=n2) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=2,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n1,B=n2) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -365,7 +389,7 @@ TEST(6_ParallelResistors)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1.2,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1.2,L=9,W=3,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -379,10 +403,14 @@ TEST(7_ParallelResistors1Swapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 2.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -409,8 +437,8 @@ TEST(7_ParallelResistors1Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n2,B=n1) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n1,B=n2) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n2,B=n1) (R=2,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n1,B=n2) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -419,7 +447,7 @@ TEST(7_ParallelResistors1Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n2,B=n1) (R=1.2,A=6,P=12);\n"
+    "  device '' r1 (A=n2,B=n1) (R=1.2,L=9,W=3,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -433,10 +461,14 @@ TEST(8_ParallelResistors1OtherSwapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 2.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -463,8 +495,8 @@ TEST(8_ParallelResistors1OtherSwapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n1) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2) (R=2,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n1) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -473,7 +505,7 @@ TEST(8_ParallelResistors1OtherSwapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1.2,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1.2,L=9,W=3,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -487,10 +519,14 @@ TEST(9_ParallelResistors2Swapped)
 
   db::Device *r1 = new db::Device (res, "r1");
   r1->set_parameter_value (db::DeviceClassResistor::param_id_R, 2.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_L, 6.0);
+  r1->set_parameter_value (db::DeviceClassResistor::param_id_W, 1.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
   r1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
   db::Device *r2 = new db::Device (res, "r2");
   r2->set_parameter_value (db::DeviceClassResistor::param_id_R, 3.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_L, 12.0);
+  r2->set_parameter_value (db::DeviceClassResistor::param_id_W, 2.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
   r2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
 
@@ -517,8 +553,8 @@ TEST(9_ParallelResistors2Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n2,B=n1) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n1) (R=3,A=1,P=2);\n"
+    "  device '' r1 (A=n2,B=n1) (R=2,L=6,W=1,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n1) (R=3,L=12,W=2,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -527,12 +563,12 @@ TEST(9_ParallelResistors2Swapped)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2);\n"
-    "  device '' r1 (A=n2,B=n1) (R=1.2,A=6,P=12);\n"
+    "  device '' r1 (A=n2,B=n1) (R=1.2,L=9,W=3,A=6,P=12);\n"
     "end;\n"
   );
 }
 
-TEST(10_ComplexRegistorCombination)
+TEST(10_ComplexResistorCombination)
 {
   db::DeviceClassResistor *res = new db::DeviceClassResistor ();
 
@@ -600,10 +636,10 @@ TEST(10_ComplexRegistorCombination)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n4);\n"
-    "  device '' r1 (A=n1,B=n2) (R=1,A=2,P=3);\n"
-    "  device '' r2 (A=n2,B=n3) (R=1,A=4,P=10);\n"
-    "  device '' r3 (A=n1,B=n3) (R=3,A=1,P=1);\n"
-    "  device '' r4 (A=n3,B=n4) (R=0.8,A=1,P=1);\n"
+    "  device '' r1 (A=n1,B=n2) (R=1,L=0,W=0,A=2,P=3);\n"
+    "  device '' r2 (A=n2,B=n3) (R=1,L=0,W=0,A=4,P=10);\n"
+    "  device '' r3 (A=n1,B=n3) (R=3,L=0,W=0,A=1,P=1);\n"
+    "  device '' r4 (A=n3,B=n4) (R=0.8,L=0,W=0,A=1,P=1);\n"
     "end;\n"
   );
 
@@ -612,7 +648,7 @@ TEST(10_ComplexRegistorCombination)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n4);\n"
-    "  device '' r4 (A=n1,B=n4) (R=2,A=8,P=15);\n"
+    "  device '' r4 (A=n1,B=n4) (R=2,L=0,W=0,A=8,P=15);\n"
     "end;\n"
   );
 }
@@ -729,12 +765,12 @@ TEST(13_SerialCapacitors)
 
   db::Device *c1 = new db::Device (cap, "c1");
   c1->set_parameter_value (db::DeviceClassCapacitor::param_id_C, 2.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 5.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 10.0);
   db::Device *c2 = new db::Device (cap, "c2");
   c2->set_parameter_value (db::DeviceClassCapacitor::param_id_C, 3.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 1.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 2.0);
 
   db::Circuit *circuit = new db::Circuit ();
   nl.add_circuit (circuit);
@@ -786,12 +822,12 @@ TEST(14_ParallelCapacitors)
 
   db::Device *c1 = new db::Device (cap, "c1");
   c1->set_parameter_value (db::DeviceClassCapacitor::param_id_C, 1.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 5.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 10.0);
   db::Device *c2 = new db::Device (cap, "c2");
   c2->set_parameter_value (db::DeviceClassCapacitor::param_id_C, 3.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 1.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 2.0);
 
   db::Circuit *circuit = new db::Circuit ();
   nl.add_circuit (circuit);
@@ -1673,12 +1709,12 @@ TEST(35_SerialCapacitorsWithBulk)
 
   db::Device *c1 = new db::Device (cap, "c1");
   c1->set_parameter_value (db::DeviceClassCapacitorWithBulk::param_id_C, 2.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 5.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 10.0);
   db::Device *c2 = new db::Device (cap, "c2");
   c2->set_parameter_value (db::DeviceClassCapacitorWithBulk::param_id_C, 3.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 1.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 2.0);
 
   db::Circuit *circuit = new db::Circuit ();
   nl.add_circuit (circuit);
@@ -1755,12 +1791,12 @@ TEST(36_ParallelCapacitorsWithBulk)
 
   db::Device *c1 = new db::Device (cap, "c1");
   c1->set_parameter_value (db::DeviceClassCapacitorWithBulk::param_id_C, 1.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_A, 5.0);
-  c1->set_parameter_value (db::DeviceClassResistor::param_id_P, 10.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 5.0);
+  c1->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 10.0);
   db::Device *c2 = new db::Device (cap, "c2");
   c2->set_parameter_value (db::DeviceClassCapacitorWithBulk::param_id_C, 3.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_A, 1.0);
-  c2->set_parameter_value (db::DeviceClassResistor::param_id_P, 2.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_A, 1.0);
+  c2->set_parameter_value (db::DeviceClassCapacitor::param_id_P, 2.0);
 
   db::Circuit *circuit = new db::Circuit ();
   nl.add_circuit (circuit);
@@ -1874,8 +1910,8 @@ TEST(37_SerialResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3,W=n2) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3,W=n2) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1884,8 +1920,8 @@ TEST(37_SerialResistorsWithBulk)
   //  no combination because bulk terminals are connected differently
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3,W=n2) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3,W=n2) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1893,8 +1929,8 @@ TEST(37_SerialResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n2,B=n3,W=nb) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n2,B=n3,W=nb) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1902,7 +1938,7 @@ TEST(37_SerialResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n3,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n3,W=nb) (R=2.5,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n3,W=nb) (R=2.5,L=0,W=0,A=6,P=12);\n"
     "end;\n"
   );
 }
@@ -1953,8 +1989,8 @@ TEST(38_ParallelResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n1,B=n2,W=n2) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n1,B=n2,W=n2) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1963,8 +1999,8 @@ TEST(38_ParallelResistorsWithBulk)
   //  devices are not combined as the bulk terminals are connected differently
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n1,B=n2,W=n2) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n1,B=n2,W=n2) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1972,8 +2008,8 @@ TEST(38_ParallelResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,A=5,P=10);\n"
-    "  device '' r2 (A=n1,B=n2,W=nb) (R=0.5,A=1,P=2);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=2,L=0,W=0,A=5,P=10);\n"
+    "  device '' r2 (A=n1,B=n2,W=nb) (R=0.5,L=0,W=0,A=1,P=2);\n"
     "end;\n"
   );
 
@@ -1981,24 +2017,32 @@ TEST(38_ParallelResistorsWithBulk)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,BULK=nb);\n"
-    "  device '' r1 (A=n1,B=n2,W=nb) (R=0.4,A=6,P=12);\n"
+    "  device '' r1 (A=n1,B=n2,W=nb) (R=0.4,L=0,W=0,A=6,P=12);\n"
     "end;\n"
   );
 }
 
-TEST(39_ParallelBipolarTransistors)
+TEST(39_ParallelBJT3Transistors)
 {
-  db::DeviceClassBipolarTransistor *cls = new db::DeviceClassBipolarTransistor ();
+  db::DeviceClassBJT3Transistor *cls = new db::DeviceClassBJT3Transistor ();
 
   db::Netlist nl;
   nl.add_device_class (cls);
 
   db::Device *d1 = new db::Device (cls, "d1");
-  d1->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_AE, 2.0);
-  d1->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_PE, 12.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AE, 2.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PE, 12.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AB, 3.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PB, 13.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AC, 4.0);
+  d1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PC, 14.0);
   db::Device *d2 = new db::Device (cls, "d2");
-  d2->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_AE, 3.0);
-  d2->set_parameter_value (db::DeviceClassBipolarTransistor::param_id_PE, 13.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AE, 3.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PE, 13.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AB, 4.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PB, 14.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AC, 5.0);
+  d2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PC, 15.0);
 
   db::Circuit *circuit = new db::Circuit ();
   nl.add_circuit (circuit);
@@ -2013,25 +2057,25 @@ TEST(39_ParallelBipolarTransistors)
   db::Net *n1 = new db::Net ("n1");
   circuit->add_net (n1);
   circuit->connect_pin (pin_a.id (), n1);
-  d1->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_C, n1);
-  d2->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_C, n1);
+  d1->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_C, n1);
+  d2->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_C, n1);
 
   db::Net *n2 = new db::Net ("n2");
   circuit->add_net (n2);
   circuit->connect_pin (pin_b.id (), n2);
-  d1->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_B, n2);
-  d2->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_B, n2);
-  d2->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_E, n2);
+  d1->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_B, n2);
+  d2->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_B, n2);
+  d2->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_E, n2);
 
   db::Net *n3 = new db::Net ("n3");
   circuit->add_net (n3);
   circuit->connect_pin (pin_c.id (), n3);
-  d1->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_E, n3);
+  d1->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_E, n3);
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,C=n3);\n"
-    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12);\n"
-    "  device '' d2 (C=n1,B=n2,E=n2) (AE=3,PE=13);\n"
+    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12,AB=3,PB=13,AC=4,PC=14);\n"
+    "  device '' d2 (C=n1,B=n2,E=n2) (AE=3,PE=13,AB=4,PB=14,AC=5,PC=15);\n"
     "end;\n"
   );
 
@@ -2040,17 +2084,17 @@ TEST(39_ParallelBipolarTransistors)
   //  no combination as emitters are connected differently
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,C=n3);\n"
-    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12);\n"
-    "  device '' d2 (C=n1,B=n2,E=n2) (AE=3,PE=13);\n"
+    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12,AB=3,PB=13,AC=4,PC=14);\n"
+    "  device '' d2 (C=n1,B=n2,E=n2) (AE=3,PE=13,AB=4,PB=14,AC=5,PC=15);\n"
     "end;\n"
   );
 
-  d2->connect_terminal (db::DeviceClassBipolarTransistor::terminal_id_E, n3);
+  d2->connect_terminal (db::DeviceClassBJT3Transistor::terminal_id_E, n3);
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,C=n3);\n"
-    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12);\n"
-    "  device '' d2 (C=n1,B=n2,E=n3) (AE=3,PE=13);\n"
+    "  device '' d1 (C=n1,B=n2,E=n3) (AE=2,PE=12,AB=3,PB=13,AC=4,PC=14);\n"
+    "  device '' d2 (C=n1,B=n2,E=n3) (AE=3,PE=13,AB=4,PB=14,AC=5,PC=15);\n"
     "end;\n"
   );
 
@@ -2058,7 +2102,7 @@ TEST(39_ParallelBipolarTransistors)
 
   EXPECT_EQ (nl.to_string (),
     "circuit '' (A=n1,B=n2,C=n3);\n"
-    "  device '' d1 (C=n1,B=n2,E=n3) (AE=5,PE=25);\n"
+    "  device '' d1 (C=n1,B=n2,E=n3) (AE=5,PE=25,AB=7,PB=27,AC=9,PC=29);\n"
     "end;\n"
   );
 }
diff --git a/src/db/unit_tests/dbNetlistExtractorTests.cc b/src/db/unit_tests/dbNetlistExtractorTests.cc
index 9d219670b..ef779b680 100644
--- a/src/db/unit_tests/dbNetlistExtractorTests.cc
+++ b/src/db/unit_tests/dbNetlistExtractorTests.cc
@@ -1355,7 +1355,7 @@ TEST(5_ResAndCapWithBulkExtraction)
   db::compare_layouts (_this, ly, au);
 }
 
-TEST(6_BipolarTransistorExtraction)
+TEST(6_BJT3TransistorExtraction)
 {
   db::Layout ly;
   db::LayerMap lmap;
@@ -1454,7 +1454,7 @@ TEST(6_BipolarTransistorExtraction)
 
   db::NetlistDeviceExtractorMOS4Transistor pmos_ex ("PMOS");
   db::NetlistDeviceExtractorMOS4Transistor nmos_ex ("NMOS");
-  db::NetlistDeviceExtractorBipolarTransistor bjt_ex ("PNP");
+  db::NetlistDeviceExtractorBJT3Transistor bjt_ex ("PNP");
 
   db::NetlistDeviceExtractor::input_layers dl;
 
diff --git a/src/db/unit_tests/dbNetlistReaderTests.cc b/src/db/unit_tests/dbNetlistReaderTests.cc
index d48d0cf85..bfa6a5a70 100644
--- a/src/db/unit_tests/dbNetlistReaderTests.cc
+++ b/src/db/unit_tests/dbNetlistReaderTests.cc
@@ -40,9 +40,9 @@ TEST(1_BasicReader)
 
   EXPECT_EQ (nl.to_string (),
     "circuit TOP ($1='1',$2='2',$3='4',$4='7');\n"
-    "  device RES $1 (A='6',B='1') (R=7650,A=0,P=0);\n"
-    "  device RES $2 (A='3',B='1') (R=7650,A=0,P=0);\n"
-    "  device RES $3 (A='3',B='2') (R=2670,A=0,P=0);\n"
+    "  device RES $1 (A='6',B='1') (R=7650,L=0,W=0,A=0,P=0);\n"
+    "  device RES $2 (A='3',B='1') (R=7650,L=0,W=0,A=0,P=0);\n"
+    "  device RES $3 (A='3',B='2') (R=2670,L=0,W=0,A=0,P=0);\n"
     "  device MHVPMOS $4 (S='6',G='4',D='7',B='7') (L=0.25,W=1.5,AS=0.63,AD=0.63,PS=3.84,PD=3.84);\n"
     "end;\n"
   );
@@ -177,4 +177,3 @@ TEST(5_CircuitParameters)
     "end;\n"
   );
 }
-
diff --git a/src/db/unit_tests/dbNetlistWriterTests.cc b/src/db/unit_tests/dbNetlistWriterTests.cc
index 7c2cad26a..4420117aa 100644
--- a/src/db/unit_tests/dbNetlistWriterTests.cc
+++ b/src/db/unit_tests/dbNetlistWriterTests.cc
@@ -1057,6 +1057,192 @@ TEST(12_UniqueNetNames)
   compare_netlists (_this, path, au_path);
 }
 
+TEST(13_WriterBJT3Devices)
+{
+  db::Netlist nl;
+
+  db::DeviceClass *rcls = new db::DeviceClassResistor ();
+  db::DeviceClass *ccls = new db::DeviceClassCapacitor ();
+  db::DeviceClass *lcls = new db::DeviceClassInductor ();
+  db::DeviceClass *dcls = new db::DeviceClassDiode ();
+  db::DeviceClass *b3cls = new db::DeviceClassBJT3Transistor ();
+  db::DeviceClass *b4cls = new db::DeviceClassBJT4Transistor ();
+
+  rcls->set_name ("RCLS");
+  lcls->set_name ("LCLS");
+  ccls->set_name ("CCLS");
+  dcls->set_name ("DCLS");
+  b3cls->set_name ("B3CLS");
+  b4cls->set_name ("B4CLS");
+
+  nl.add_device_class (rcls);
+  nl.add_device_class (lcls);
+  nl.add_device_class (ccls);
+  nl.add_device_class (dcls);
+  nl.add_device_class (b3cls);
+  nl.add_device_class (b4cls);
+
+  db::Circuit *circuit1 = new db::Circuit ();
+  circuit1->set_name ("C1");
+  nl.add_circuit (circuit1);
+
+  db::Net *n1, *n2, *n3, *n4;
+  n1 = new db::Net ();
+  n1->set_name ("n1");
+  circuit1->add_net (n1);
+  n2 = new db::Net ();
+  n2->set_name ("n2");
+  circuit1->add_net (n2);
+  n3 = new db::Net ();
+  n3->set_name ("n3");
+  circuit1->add_net (n3);
+  n4 = new db::Net ();
+  n4->set_name ("n4");
+  circuit1->add_net (n4);
+
+  db::Device *ddev1 = new db::Device (b3cls);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AE, 0.25);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PE, 0.18);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AB, 1.2);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PB, 0.75);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AC, 1.0);
+  ddev1->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PC, 0.6);
+  db::Device *ddev2 = new db::Device (b3cls);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AE, 1.2);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PE, 2.5);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AB, 1.4);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PB, 2.8);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_AC, 1.5);
+  ddev2->set_parameter_value (db::DeviceClassBJT3Transistor::param_id_PC, 3.0);
+  circuit1->add_device (ddev1);
+  circuit1->add_device (ddev2);
+
+  size_t pid1 = circuit1->add_pin ("p1").id ();
+  size_t pid2 = circuit1->add_pin ("p2").id ();
+  size_t pid3 = circuit1->add_pin ("p3").id ();
+
+  circuit1->connect_pin (pid1, n1);
+  circuit1->connect_pin (pid2, n2);
+  circuit1->connect_pin (pid3, n4);
+
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("E"), n1);
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("B"), n4);
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("C"), n3);
+  ddev2->connect_terminal (ddev2->device_class ()->terminal_id_for_name ("E"), n3);
+  ddev2->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("B"), n4);
+  ddev2->connect_terminal (ddev2->device_class ()->terminal_id_for_name ("C"), n2);
+
+  //  verify against the input
+
+  std::string path = tmp_file ("tmp_nwriter13.txt");
+  {
+    tl::OutputStream stream (path);
+    db::NetlistSpiceWriter writer;
+    writer.write (stream, nl, "written by unit test");
+  }
+
+  std::string au_path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "nwriter13_au.txt");
+
+  compare_netlists (_this, path, au_path);
+}
+
+TEST(14_WriterBJT4Devices)
+{
+  db::Netlist nl;
+
+  db::DeviceClass *rcls = new db::DeviceClassResistor ();
+  db::DeviceClass *ccls = new db::DeviceClassCapacitor ();
+  db::DeviceClass *lcls = new db::DeviceClassInductor ();
+  db::DeviceClass *dcls = new db::DeviceClassDiode ();
+  db::DeviceClass *b3cls = new db::DeviceClassBJT3Transistor ();
+  db::DeviceClass *b4cls = new db::DeviceClassBJT4Transistor ();
+
+  rcls->set_name ("RCLS");
+  lcls->set_name ("LCLS");
+  ccls->set_name ("CCLS");
+  dcls->set_name ("DCLS");
+  b3cls->set_name ("B3CLS");
+  b4cls->set_name ("B4CLS");
+
+  nl.add_device_class (rcls);
+  nl.add_device_class (lcls);
+  nl.add_device_class (ccls);
+  nl.add_device_class (dcls);
+  nl.add_device_class (b3cls);
+  nl.add_device_class (b4cls);
+
+  db::Circuit *circuit1 = new db::Circuit ();
+  circuit1->set_name ("C1");
+  nl.add_circuit (circuit1);
+
+  db::Net *n1, *n2, *n3, *n4, *n5;
+  n1 = new db::Net ();
+  n1->set_name ("n1");
+  circuit1->add_net (n1);
+  n2 = new db::Net ();
+  n2->set_name ("n2");
+  circuit1->add_net (n2);
+  n3 = new db::Net ();
+  n3->set_name ("n3");
+  circuit1->add_net (n3);
+  n4 = new db::Net ();
+  n4->set_name ("n4");
+  circuit1->add_net (n4);
+  n5 = new db::Net ();
+  n5->set_name ("n5");
+  circuit1->add_net (n5);
+
+  db::Device *ddev1 = new db::Device (b4cls);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AE, 0.25);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PE, 0.18);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AB, 1.2);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PB, 0.75);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AC, 1.0);
+  ddev1->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PC, 0.6);
+  db::Device *ddev2 = new db::Device (b4cls);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AE, 1.2);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PE, 2.5);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AB, 1.4);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PB, 2.8);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_AC, 1.5);
+  ddev2->set_parameter_value (db::DeviceClassBJT4Transistor::param_id_PC, 3.0);
+  circuit1->add_device (ddev1);
+  circuit1->add_device (ddev2);
+
+  size_t pid1 = circuit1->add_pin ("p1").id ();
+  size_t pid2 = circuit1->add_pin ("p2").id ();
+  size_t pid3 = circuit1->add_pin ("p3").id ();
+  size_t pid4 = circuit1->add_pin ("p4").id ();
+
+  circuit1->connect_pin (pid1, n1);
+  circuit1->connect_pin (pid2, n2);
+  circuit1->connect_pin (pid3, n4);
+  circuit1->connect_pin (pid4, n5);
+
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("E"), n1);
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("B"), n4);
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("C"), n3);
+  ddev1->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("S"), n5);
+  ddev2->connect_terminal (ddev2->device_class ()->terminal_id_for_name ("E"), n3);
+  ddev2->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("B"), n4);
+  ddev2->connect_terminal (ddev2->device_class ()->terminal_id_for_name ("C"), n2);
+  ddev2->connect_terminal (ddev1->device_class ()->terminal_id_for_name ("S"), n5);
+
+  //  verify against the input
+
+  std::string path = tmp_file ("tmp_nwriter14.txt");
+  {
+    tl::OutputStream stream (path);
+    db::NetlistSpiceWriter writer;
+    writer.write (stream, nl, "written by unit test");
+  }
+
+  std::string au_path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "nwriter14_au.txt");
+
+  compare_netlists (_this, path, au_path);
+}
+
+
 namespace {
 
 class MyDelegate
diff --git a/src/laybasic/laybasic/layNetlistBrowserModel.cc b/src/laybasic/laybasic/layNetlistBrowserModel.cc
index acf94560f..6672f0700 100644
--- a/src/laybasic/laybasic/layNetlistBrowserModel.cc
+++ b/src/laybasic/laybasic/layNetlistBrowserModel.cc
@@ -1532,7 +1532,7 @@ static QIcon icon_for_device (const db::DeviceClass *dc)
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_diode_32.png")));
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_diode_24.png")));
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_diode_16.png")));
-  } else if (dynamic_cast<const db::DeviceClassBipolarTransistor *> (dc)) {
+  } else if (dynamic_cast<const db::DeviceClassBJT3Transistor *> (dc)) {
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_bjt_48.png")));
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_bjt_32.png")));
     icon.addPixmap (QPixmap (QString::fromUtf8 (":/images/icon_device_bjt_24.png")));
diff --git a/testdata/algo/nwriter4_au.txt b/testdata/algo/nwriter4_au.txt
index 6048bee16..181fefac7 100644
--- a/testdata/algo/nwriter4_au.txt
+++ b/testdata/algo/nwriter4_au.txt
@@ -8,7 +8,7 @@
 * net 2 n2
 * net 3 n3
 * device instance $1 r0 *1 0,0 DCLS
-D$1 1 3 DDCLS
+D$1 1 3 DCLS A=1.7e-10P P=0P
 * device instance $2 r0 *1 0,0 DCLS
-D$2 3 2 DDCLS
+D$2 3 2 DCLS A=4.2e-08P P=0P
 .ENDS C1