diff --git a/src/spicelib/devices/mos3/mos3.c b/src/spicelib/devices/mos3/mos3.c
index 3d4532ea2..b64ea5829 100644
--- a/src/spicelib/devices/mos3/mos3.c
+++ b/src/spicelib/devices/mos3/mos3.c
@@ -37,6 +37,7 @@ IFparm MOS3pTable[] = { /* parameters */
  IOPAU("icvbs",       MOS3_IC_VBS,  IF_REAL   , "Initial B-S voltage"),
  IOPU("ic",     MOS3_IC,      IF_REALVEC, "Vector of D-S, G-S, B-S voltages"),
  IOPU("temp",      MOS3_TEMP,    IF_REAL   , "Instance operating temperature"),
+  IOPU("dtemp",      MOS3_DTEMP,    IF_REAL   , "Instance temperature difference"),
  IP("sens_l",  MOS3_L_SENS, IF_FLAG, "flag to request sensitivity WRT length"),
  IP("sens_w",  MOS3_W_SENS, IF_FLAG, "flag to request sensitivity WRT width"),
  OPU("dnode",     MOS3_DNODE,   IF_INTEGER, "Number of drain node"),
diff --git a/src/spicelib/devices/mos3/mos3acld.c b/src/spicelib/devices/mos3/mos3acld.c
index 761f5e47a..ea2d82854 100644
--- a/src/spicelib/devices/mos3/mos3acld.c
+++ b/src/spicelib/devices/mos3/mos3acld.c
@@ -14,9 +14,7 @@ Modified: 2000 AlansFixes
 
 
 int
-MOS3acLoad(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3acLoad(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3ask.c b/src/spicelib/devices/mos3/mos3ask.c
index 5275b6578..ef413f9dd 100644
--- a/src/spicelib/devices/mos3/mos3ask.c
+++ b/src/spicelib/devices/mos3/mos3ask.c
@@ -15,12 +15,8 @@ Modified: 2000 AlansFixes
 
 /*ARGSUSED*/
 int
-MOS3ask(ckt,inst,which,value,select)
-    CKTcircuit *ckt;
-    GENinstance *inst;
-    int which;
-    IFvalue *value;
-    IFvalue *select;
+MOS3ask(CKTcircuit *ckt, GENinstance *inst, int which, IFvalue *value,
+        IFvalue *select)
 {
     MOS3instance *here = (MOS3instance *)inst;
     double vr;
@@ -33,6 +29,9 @@ MOS3ask(ckt,inst,which,value,select)
         case MOS3_TEMP:
             value->rValue = here->MOS3temp-CONSTCtoK;
             return(OK);
+        case MOS3_DTEMP:
+            value->rValue = here->MOS3dtemp;
+            return(OK);
         case MOS3_CGS:
             value->rValue = 2* *(ckt->CKTstate0 + here->MOS3capgs);
             return(OK);
diff --git a/src/spicelib/devices/mos3/mos3conv.c b/src/spicelib/devices/mos3/mos3conv.c
index 2da77c09f..5c18abc37 100644
--- a/src/spicelib/devices/mos3/mos3conv.c
+++ b/src/spicelib/devices/mos3/mos3conv.c
@@ -10,9 +10,7 @@ Author: 1985 Thomas L. Quarles
 #include "suffix.h"
 
 int
-MOS3convTest(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3convTest(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3defs.h b/src/spicelib/devices/mos3/mos3defs.h
index 8569eb597..c0cff0ef6 100644
--- a/src/spicelib/devices/mos3/mos3defs.h
+++ b/src/spicelib/devices/mos3/mos3defs.h
@@ -43,6 +43,7 @@ typedef struct sMOS3instance {
     double MOS3sourceConductance;   /*conductance of source(or 0):set in setup*/
     double MOS3drainConductance;    /*conductance of drain(or 0):set in setup*/
     double MOS3temp;    /* operating temperature of this instance */
+    double MOS3dtemp;    /* temperature difference for this instance */
 
     double MOS3tTransconductance;   /* temperature corrected transconductance*/
     double MOS3tSurfMob;            /* temperature corrected surface mobility */
@@ -91,7 +92,8 @@ typedef struct sMOS3instance {
 
     unsigned MOS3off :1;/* non-zero to indicate device is off for dc analysis*/
     unsigned MOS3tempGiven :1;  /* instance temperature specified */
-     unsigned MOS3mGiven :1;
+    unsigned MOS3dtempGiven :1;  /* instance temperature difference specified */
+    unsigned MOS3mGiven :1;
     unsigned MOS3lGiven :1;
     unsigned MOS3wGiven :1;
     unsigned MOS3drainAreaGiven :1;
@@ -496,7 +498,8 @@ typedef struct sMOS3model {       /* model structure for a resistor */
 #define MOS3_TEMP               77
 #define MOS3_SOURCERESIST       78
 #define MOS3_DRAINRESIST        79
-#define MOS3_M 80
+#define MOS3_M                  80
+#define MOS3_DTEMP              81
 
 /* model parameters */
 #define MOS3_MOD_VTO 101
diff --git a/src/spicelib/devices/mos3/mos3del.c b/src/spicelib/devices/mos3/mos3del.c
index a67d0b24d..2028bdd42 100644
--- a/src/spicelib/devices/mos3/mos3del.c
+++ b/src/spicelib/devices/mos3/mos3del.c
@@ -12,10 +12,7 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-MOS3delete(inModel,name,inst)
-    GENmodel *inModel;
-    IFuid name;
-    GENinstance **inst;
+MOS3delete(GENmodel *inModel, IFuid name, GENinstance **inst)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance **fast = (MOS3instance **)inst;
diff --git a/src/spicelib/devices/mos3/mos3dest.c b/src/spicelib/devices/mos3/mos3dest.c
index f8b4cadc9..df7131bde 100644
--- a/src/spicelib/devices/mos3/mos3dest.c
+++ b/src/spicelib/devices/mos3/mos3dest.c
@@ -11,8 +11,7 @@ Author: 1985 Thomas L. Quarles
 
 
 void
-MOS3destroy(inModel)
-    GENmodel **inModel;
+MOS3destroy(GENmodel **inModel)
 {
     MOS3model **model = (MOS3model **)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3dist.c b/src/spicelib/devices/mos3/mos3dist.c
index c8f762a49..25f1a8347 100644
--- a/src/spicelib/devices/mos3/mos3dist.c
+++ b/src/spicelib/devices/mos3/mos3dist.c
@@ -11,11 +11,7 @@ Author: 1988 Jaijeet S Roychowdhury
 #include "suffix.h"
 
 int
-MOS3disto(mode,genmodel,ckt)
- GENmodel *genmodel;
- CKTcircuit *ckt;
- int mode;
-
+MOS3disto(int mode, GENmodel *genmodel, CKTcircuit *ckt)
 /* assuming here that ckt->CKTomega has been initialised to 
  * the correct value
  */
diff --git a/src/spicelib/devices/mos3/mos3dset.c b/src/spicelib/devices/mos3/mos3dset.c
index ecebbeaf3..1da1b1fe3 100644
--- a/src/spicelib/devices/mos3/mos3dset.c
+++ b/src/spicelib/devices/mos3/mos3dset.c
@@ -15,9 +15,7 @@ Modified: 2000 AlansFixes
 #include "suffix.h"
 
 int
-MOS3dSetup(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3dSetup(GENmodel *inModel, CKTcircuit *ckt)
         /* actually load the current value into the 
          * sparse matrix previously provided 
          */
diff --git a/src/spicelib/devices/mos3/mos3ext.h b/src/spicelib/devices/mos3/mos3ext.h
index 4807683a0..843d68329 100644
--- a/src/spicelib/devices/mos3/mos3ext.h
+++ b/src/spicelib/devices/mos3/mos3ext.h
@@ -4,7 +4,6 @@ Author: 1985 Thomas L. Quarles
 Modified: 2000 AlansFixes
 **********/
 
-#ifdef __STDC__
 extern int MOS3acLoad(GENmodel*,CKTcircuit*);
 extern int MOS3ask(CKTcircuit*,GENinstance*,int,IFvalue*,IFvalue*);
 extern int MOS3convTest(GENmodel *,CKTcircuit *);
@@ -29,28 +28,3 @@ extern int MOS3trunc(GENmodel*,CKTcircuit*,double*);
 extern int MOS3disto(int,GENmodel*,CKTcircuit*);
 extern int MOS3noise(int,int,GENmodel*,CKTcircuit*,Ndata*,double*);
 extern int MOS3dSetup(GENmodel*,CKTcircuit*);
-#else /* stdc */
-extern int MOS3acLoad();
-extern int MOS3ask();
-extern int MOS3convTest();
-extern int MOS3delete();
-extern void MOS3destroy();
-extern int MOS3getic();
-extern int MOS3load();
-extern int MOS3mAsk();
-extern int MOS3mDelete();
-extern int MOS3mParam();
-extern int MOS3param();
-extern int MOS3pzLoad();
-extern int MOS3sAcLoad();
-extern int MOS3sLoad();
-extern void MOS3sPrint();
-extern int MOS3sSetup();
-extern int MOS3sUpdate();
-extern int MOS3setup();
-extern int MOS3unsetup();
-extern int MOS3temp();
-extern int MOS3trunc();
-extern int MOS3disto();
-extern int MOS3noise();
-#endif /* stdc */
diff --git a/src/spicelib/devices/mos3/mos3ic.c b/src/spicelib/devices/mos3/mos3ic.c
index 8341b69d0..05d0443a8 100644
--- a/src/spicelib/devices/mos3/mos3ic.c
+++ b/src/spicelib/devices/mos3/mos3ic.c
@@ -13,9 +13,7 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-MOS3getic(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3getic(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3mask.c b/src/spicelib/devices/mos3/mos3mask.c
index 84f599820..2f2c6a156 100644
--- a/src/spicelib/devices/mos3/mos3mask.c
+++ b/src/spicelib/devices/mos3/mos3mask.c
@@ -18,11 +18,7 @@ Modified: 2000 AlansFixes
 
 /*ARGSUSED*/
 int
-MOS3mAsk(ckt,inst,which,value)
-    CKTcircuit *ckt;
-    GENmodel *inst;
-    int which;
-    IFvalue *value;
+MOS3mAsk(CKTcircuit *ckt, GENmodel *inst, int which, IFvalue *value)
 {
     MOS3model *here = (MOS3model *)inst;
     switch(which) {
diff --git a/src/spicelib/devices/mos3/mos3mdel.c b/src/spicelib/devices/mos3/mos3mdel.c
index 6deeffe3f..0a230684e 100644
--- a/src/spicelib/devices/mos3/mos3mdel.c
+++ b/src/spicelib/devices/mos3/mos3mdel.c
@@ -12,10 +12,7 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-MOS3mDelete(inModel,modname,kill)
-    GENmodel **inModel;
-    IFuid modname;
-    GENmodel *kill;
+MOS3mDelete(GENmodel **inModel, IFuid modname, GENmodel *kill)
 {
     MOS3model **model = (MOS3model **)inModel;
     MOS3model *modfast = (MOS3model *)kill;
diff --git a/src/spicelib/devices/mos3/mos3mpar.c b/src/spicelib/devices/mos3/mos3mpar.c
index a9ee5fbe5..3e3563b18 100644
--- a/src/spicelib/devices/mos3/mos3mpar.c
+++ b/src/spicelib/devices/mos3/mos3mpar.c
@@ -15,10 +15,7 @@ Modified: 2000 AlansFixes
 
 
 int
-MOS3mParam(param,value,inModel)
-    int param;
-    IFvalue *value;
-    GENmodel *inModel;
+MOS3mParam(int param, IFvalue *value, GENmodel *inModel)
 {
     MOS3model *model = (MOS3model *)inModel;
     switch(param) {
diff --git a/src/spicelib/devices/mos3/mos3noi.c b/src/spicelib/devices/mos3/mos3noi.c
index adf6c8e45..96f33a573 100644
--- a/src/spicelib/devices/mos3/mos3noi.c
+++ b/src/spicelib/devices/mos3/mos3noi.c
@@ -24,13 +24,8 @@ extern void   NevalSrc();
 extern double Nintegrate();
 
 int
-MOS3noise (mode, operation, genmodel, ckt, data, OnDens)
-    int mode;
-    int operation;
-    GENmodel *genmodel;
-    CKTcircuit *ckt;
-    Ndata *data;
-    double *OnDens;
+MOS3noise (int mode, int operation, GENmodel *genmodel, CKTcircuit *ckt, 
+           Ndata *data, double *OnDens)
 {
     MOS3model *firstModel = (MOS3model *) genmodel;
     MOS3model *model;
diff --git a/src/spicelib/devices/mos3/mos3par.c b/src/spicelib/devices/mos3/mos3par.c
index 87dd024cc..2cf27a8cb 100644
--- a/src/spicelib/devices/mos3/mos3par.c
+++ b/src/spicelib/devices/mos3/mos3par.c
@@ -16,11 +16,7 @@ Modified: 2000 AlansFixes
 
 /* ARGSUSED */
 int
-MOS3param(param,value,inst,select)
-    int param;
-    IFvalue *value;
-    GENinstance *inst;
-    IFvalue *select;
+MOS3param(int param, IFvalue *value, GENinstance *inst, IFvalue *select)
 {
     MOS3instance *here = (MOS3instance *)inst;
     switch(param) {
@@ -80,6 +76,10 @@ MOS3param(param,value,inst,select)
             here->MOS3temp = value->rValue+CONSTCtoK;
             here->MOS3tempGiven = TRUE;
             break;
+        case MOS3_DTEMP:
+            here->MOS3dtemp = value->rValue;
+            here->MOS3dtempGiven = TRUE;
+            break;
         case MOS3_IC:
             switch(value->v.numValue){
                 case 3:
diff --git a/src/spicelib/devices/mos3/mos3pzld.c b/src/spicelib/devices/mos3/mos3pzld.c
index 1776b319b..a44f0a598 100644
--- a/src/spicelib/devices/mos3/mos3pzld.c
+++ b/src/spicelib/devices/mos3/mos3pzld.c
@@ -15,10 +15,7 @@ Modified: 2000 AlansFixes
 
 
 int
-MOS3pzLoad(inModel,ckt,s)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
-    SPcomplex *s;
+MOS3pzLoad(GENmodel *inModel, CKTcircuit *ckt, SPcomplex *s)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3sacl.c b/src/spicelib/devices/mos3/mos3sacl.c
index 5d334e8e8..a4117cedc 100644
--- a/src/spicelib/devices/mos3/mos3sacl.c
+++ b/src/spicelib/devices/mos3/mos3sacl.c
@@ -1,6 +1,8 @@
 /**********
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
+
+This function is obsolete (was used by an old sensitivity analysis)
 **********/
 
 /* actually load the current ac sensitivity 
@@ -16,9 +18,7 @@ Author: 1985 Thomas L. Quarles
 #include "suffix.h"
 
 int
-MOS3sAcLoad(inModel,ckt)
-GENmodel *inModel;
-CKTcircuit *ckt;
+MOS3sAcLoad(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3set.c b/src/spicelib/devices/mos3/mos3set.c
index 2662957f1..8fc9d4e4d 100644
--- a/src/spicelib/devices/mos3/mos3set.c
+++ b/src/spicelib/devices/mos3/mos3set.c
@@ -1,6 +1,6 @@
 /**********
 Copyright 1990 Regents of the University of California.  All rights reserved.
-Author: 1985 Thomas L. Quarlesù
+Author: 1985 Thomas L. Quarlesù
 Modified: 2000 AlansFixes
 **********/
 
@@ -16,11 +16,7 @@ Modified: 2000 AlansFixes
 #define EPSSIL (11.7 * 8.854214871e-12)
 
 int
-MOS3setup(matrix,inModel,ckt,states)
-    SMPmatrix *matrix;
-    GENmodel *inModel;
-    CKTcircuit *ckt;
-    int *states;
+MOS3setup(SMPmatrix *matrix, GENmodel *inModel, CKTcircuit *ckt, int *states)
         /* load the MOS3 device structure with those pointers needed later 
          * for fast matrix loading 
          */
@@ -264,9 +260,7 @@ if((here->ptr = SMPmakeElt(matrix,here->first,here->second))==(double *)NULL){\
 }
 
 int
-MOS3unsetup(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3unsetup(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3sld.c b/src/spicelib/devices/mos3/mos3sld.c
index cea6e2437..d33664af4 100644
--- a/src/spicelib/devices/mos3/mos3sld.c
+++ b/src/spicelib/devices/mos3/mos3sld.c
@@ -2,6 +2,8 @@
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
 Modified: 2000 AlansFixes
+
+This function is obsolete (was used by an old sensitivity analysis)
 **********/
 
 /* actually load the current sensitivity 
@@ -16,9 +18,7 @@ Modified: 2000 AlansFixes
 #include "suffix.h"
 
 int
-MOS3sLoad(inModel,ckt)
-GENmodel *inModel;
-CKTcircuit *ckt;
+MOS3sLoad(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3sprt.c b/src/spicelib/devices/mos3/mos3sprt.c
index 1bc20e8ac..cd6573e27 100644
--- a/src/spicelib/devices/mos3/mos3sprt.c
+++ b/src/spicelib/devices/mos3/mos3sprt.c
@@ -2,6 +2,8 @@
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
 Modified: 2000 AlansFixes
+
+This function is obsolete (was used by an old sensitivity analysis)
 **********/
 
     /* Pretty print the sensitivity info for all the MOS3 
@@ -16,9 +18,7 @@ Modified: 2000 AlansFixes
 #include "suffix.h"
 
 void
-MOS3sPrint(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3sPrint(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3sset.c b/src/spicelib/devices/mos3/mos3sset.c
index 23ba965ad..4d10762d0 100644
--- a/src/spicelib/devices/mos3/mos3sset.c
+++ b/src/spicelib/devices/mos3/mos3sset.c
@@ -1,6 +1,8 @@
 /**********
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
+
+This function is obsolete (was used by an old sensitivity analysis)
 **********/
 
     /* loop through all the devices and 
@@ -15,9 +17,7 @@ Author: 1985 Thomas L. Quarles
 #include "suffix.h"
 
 int
-MOS3sSetup(info,inModel)
-    SENstruct *info;
-    GENmodel *inModel;
+MOS3sSetup(SENstruct *info, GENmodel *inModel)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3supd.c b/src/spicelib/devices/mos3/mos3supd.c
index 22e294e1c..e09472b5c 100644
--- a/src/spicelib/devices/mos3/mos3supd.c
+++ b/src/spicelib/devices/mos3/mos3supd.c
@@ -1,6 +1,8 @@
 /**********
 Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
+
+This function is obsolete (was used by an old sensitivity analysis)
 **********/
 
 #include "ngspice.h"
@@ -11,9 +13,7 @@ Author: 1985 Thomas L. Quarles
 #include "suffix.h"
 
 int
-MOS3sUpdate(inModel,ckt)
-GENmodel *inModel;
-CKTcircuit *ckt;
+MOS3sUpdate(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
diff --git a/src/spicelib/devices/mos3/mos3temp.c b/src/spicelib/devices/mos3/mos3temp.c
index d226ab369..52934f339 100644
--- a/src/spicelib/devices/mos3/mos3temp.c
+++ b/src/spicelib/devices/mos3/mos3temp.c
@@ -15,9 +15,7 @@ Modified: 2000 AlansFixes
 #define EPSSIL (11.7 * 8.854214871e-12)
 
 int
-MOS3temp(inModel,ckt)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
+MOS3temp(GENmodel *inModel, CKTcircuit *ckt)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;
@@ -126,8 +124,12 @@ MOS3temp(inModel,ckt)
 
             /* perform the parameter defaulting */
 
+             if(!here->MOS3dtempGiven) {
+                here->MOS3dtemp = 0.0;
+            }
+
             if(!here->MOS3tempGiven) {
-                here->MOS3temp = ckt->CKTtemp;
+                here->MOS3temp = ckt->CKTtemp + here->MOS3dtemp;
             }
             vt = here->MOS3temp * CONSTKoverQ;
             ratio = here->MOS3temp/model->MOS3tnom;
diff --git a/src/spicelib/devices/mos3/mos3trun.c b/src/spicelib/devices/mos3/mos3trun.c
index a60659996..3ec6922a4 100644
--- a/src/spicelib/devices/mos3/mos3trun.c
+++ b/src/spicelib/devices/mos3/mos3trun.c
@@ -10,10 +10,7 @@ Author: 1985 Thomas L. Quarles
 #include "suffix.h"
 
 int
-MOS3trunc(inModel,ckt,timeStep)
-    GENmodel *inModel;
-    CKTcircuit *ckt;
-    double *timeStep;
+MOS3trunc(GENmodel *inModel, CKTcircuit *ckt, double *timeStep)
 {
     MOS3model *model = (MOS3model *)inModel;
     MOS3instance *here;