diff --git a/configure.ac b/configure.ac
index 6f043c113..388e29169 100644
--- a/configure.ac
+++ b/configure.ac
@@ -800,6 +800,7 @@ AC_MSG_RESULT([Settings which were chosen:])
 if test "x$enable_sense2" = xyes; then
     AC_DEFINE([WANT_SENSE2], [], [Define if we want spice2 sensitivity analysis])
     AC_MSG_RESULT([Spice2 sensitivity analysis enabled])
+    AC_MSG_WARN([This feature is UNSUPPORTED])
 fi
 if test "x$enable_nobypass" = xyes; then
     AC_DEFINE([NOBYPASS], [], [Define if we want NOBYPASS])
@@ -943,6 +944,8 @@ AM_CONDITIONAL([NUMDEV_WANTED], [test "x$enable_cider" = xyes])
 
 AM_CONDITIONAL([PSS_WANTED], [test "x$enable_pss" = xyes])
 
+AM_CONDITIONAL([SENSE2_WANTED], [test "x$enable_sense2" = xyes])
+
 # adms option
 if test "x$enable_adms" = xyes ; then
     AC_MSG_RESULT([**********************************
@@ -1167,6 +1170,7 @@ AC_CONFIG_FILES([Makefile
                  src/xspice/enh/Makefile
                  src/xspice/ipc/Makefile
                  src/xspice/idn/Makefile
+                 src/unsupported/Makefile
                  tests/Makefile
                  tests/bsim1/Makefile
                  tests/bsim2/Makefile
diff --git a/src/Makefile.am b/src/Makefile.am
index 7deac3cfe..8e88ab681 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,7 +1,7 @@
 ## Process this file with automake to produce Makefile.in
 
 SUBDIRS = misc maths frontend spicelib include/ngspice
-DIST_SUBDIRS = misc maths frontend spicelib include/ngspice xspice ciderlib
+DIST_SUBDIRS = misc maths frontend spicelib include/ngspice xspice ciderlib unsupported
 
 if XSPICE_WANTED
 SUBDIRS += xspice
@@ -11,6 +11,10 @@ if CIDER_WANTED
 SUBDIRS += ciderlib
 endif
 
+if SENSE2_WANTED
+SUBDIRS += unsupported
+endif
+
 if !TCL_MODULE
 if !SHARED_MODULE
 bin_PROGRAMS =  ngspice ngnutmeg
@@ -27,7 +31,7 @@ endif !SHARED_MODULE
 endif !TCL_MODULE
 
 EXTRA_DIST = ngspice.txt setplot spectrum \
-	     devload devaxis ciderinit winmain.c winmain.h unsupported \
+	     devload devaxis ciderinit winmain.c winmain.h \
 	     tclspice.c tclspice.map pkgIndex.tcl.in spinit.in tclspinit.in \
 	     main.c sharedspice.c
 
@@ -137,6 +141,10 @@ ngspice_LDADD += \
 	spicelib/analysis/libckt.la \
 	spicelib/devices/libdev.la
 
+if SENSE2_WANTED
+ngspice_LDADD += unsupported/libunsupported.la
+endif
+
 if XSPICE_WANTED
 ngspice_LDADD += \
 	xspice/cm/libcmxsp.la \
diff --git a/src/include/ngspice/cktdefs.h b/src/include/ngspice/cktdefs.h
index f4b2aba47..80ac6259e 100644
--- a/src/include/ngspice/cktdefs.h
+++ b/src/include/ngspice/cktdefs.h
@@ -382,10 +382,14 @@ extern int PZinit(CKTcircuit *);
 extern int PZpost(CKTcircuit *);
 extern int PZaskQuest(CKTcircuit *, JOB *, int , IFvalue *);
 extern int PZsetParm(CKTcircuit *, JOB *, int , IFvalue *);
+
+#ifdef WANT_SENSE2
 extern int SENaskQuest(CKTcircuit *, JOB *, int , IFvalue *);
 extern void SENdestroy(SENstruct *);
 extern int SENsetParm(CKTcircuit *, JOB *, int , IFvalue *);
-extern int SENstartup(CKTcircuit *);
+extern int SENstartup(CKTcircuit *, int);
+#endif
+
 extern int SPIinit(IFfrontEnd *, IFsimulator **);
 extern int TFanal(CKTcircuit *, int);
 extern int TFaskQuest(CKTcircuit *, JOB *, int , IFvalue *);
diff --git a/src/spicelib/analysis/analysis.c b/src/spicelib/analysis/analysis.c
index cbb3bd4ec..ecb9279a6 100644
--- a/src/spicelib/analysis/analysis.c
+++ b/src/spicelib/analysis/analysis.c
@@ -20,6 +20,10 @@ extern SPICEanalysis SENSinfo;
 extern SPICEanalysis PSSinfo;
 #endif
 
+#ifdef WANT_SENSE2
+extern SPICEanalysis SEN2info;
+#endif
+
 SPICEanalysis *analInfo[] = {
     &OPTinfo,
     &ACinfo,
@@ -34,6 +38,9 @@ SPICEanalysis *analInfo[] = {
 #ifdef WITH_PSS
     &PSSinfo,
 #endif
+#ifdef WANT_SENSE2
+    &SEN2info,
+#endif
 };
 
 
diff --git a/src/spicelib/analysis/cktsetup.c b/src/spicelib/analysis/cktsetup.c
index 49a99d80d..446749094 100644
--- a/src/spicelib/analysis/cktsetup.c
+++ b/src/spicelib/analysis/cktsetup.c
@@ -43,7 +43,9 @@ CKTsetup(CKTcircuit *ckt)
 
 #ifdef WANT_SENSE2
     if(ckt->CKTsenInfo){
-        if (error = CKTsenSetup(ckt)) return(error);
+        error = CKTsenSetup(ckt);
+        if (error)
+            return(error);
     }
 #endif
 
diff --git a/src/spicelib/analysis/dcop.c b/src/spicelib/analysis/dcop.c
index 64d5d85d2..55c79d90e 100644
--- a/src/spicelib/analysis/dcop.c
+++ b/src/spicelib/analysis/dcop.c
@@ -21,6 +21,11 @@ Modified: 2000  AlansFixes
 int
 DCop(CKTcircuit *ckt, int notused)
 {
+#ifdef WANT_SENSE2
+    int i, senmode, size;
+    long save;
+#endif
+
     int converged;
     int error;
     IFuid *nameList; /* va: tmalloc'ed list */
@@ -133,7 +138,10 @@ DCop(CKTcircuit *ckt, int notused)
          for(i = 1; i<=size ; i++){
              ckt->CKTrhsOp[i] = ckt->CKTrhsOld[i];
          }
-         if(error = CKTsenDCtran(ckt)) return(error);
+         error = CKTsenDCtran(ckt);
+         if (error)
+             return(error);
+
          ckt->CKTmode = save;
          ckt->CKTsenInfo->SENmode = senmode;
 
diff --git a/src/spicelib/analysis/dctran.c b/src/spicelib/analysis/dctran.c
index 708af9130..ff9dee3e7 100644
--- a/src/spicelib/analysis/dctran.c
+++ b/src/spicelib/analysis/dctran.c
@@ -78,6 +78,8 @@ DCtran(CKTcircuit *ckt,
     int firsttime;
     int error;
 #ifdef WANT_SENSE2
+    int save, save2, size;
+    long save1;
 #ifdef SENSDEBUG
     FILE *outsen;
 #endif /* SENSDEBUG */
@@ -316,7 +318,10 @@ DCtran(CKTcircuit *ckt,
             save2 = ckt->CKTorder;
             ckt->CKTmode = save_mode;
             ckt->CKTorder = save_order;
-            if(error = CKTsenDCtran(ckt)) return(error);
+            error = CKTsenDCtran(ckt);
+            if (error)
+                return(error);
+
             ckt->CKTmode = save1;
             ckt->CKTorder = save2;
         }
@@ -792,7 +797,10 @@ resume:
                     save2 = ckt->CKTorder;
                     ckt->CKTmode = save_mode;
                     ckt->CKTorder = save_order;
-                    if(error = CKTsenDCtran(ckt)) return(error);
+                    error = CKTsenDCtran (ckt);
+                    if (error)
+                        return(error);
+
                     ckt->CKTmode = save1;
                     ckt->CKTorder = save2;
                 }
@@ -852,7 +860,10 @@ resume:
                     save2 = ckt->CKTorder;
                     ckt->CKTmode = save_mode;
                     ckt->CKTorder = save_order;
-                    if(error = CKTsenDCtran(ckt)) return(error);
+                    error = CKTsenDCtran(ckt);
+                    if (error)
+                        return (error);
+
                     ckt->CKTmode = save1;
                     ckt->CKTorder = save2;
                 }
diff --git a/src/spicelib/analysis/dctrcurv.c b/src/spicelib/analysis/dctrcurv.c
index 49e4742b9..f4d4f82c9 100644
--- a/src/spicelib/analysis/dctrcurv.c
+++ b/src/spicelib/analysis/dctrcurv.c
@@ -50,6 +50,7 @@ DCtrCurv(CKTcircuit *ckt, int restart)
     static runDesc *plot = NULL;
 
 #ifdef WANT_SENSE2
+    long save;
 #ifdef SENSDEBUG
     if(ckt->CKTsenInfo && (ckt->CKTsenInfo->SENmode&DCSEN) ){
         printf("\nDC Sensitivity Results\n\n");
@@ -458,7 +459,10 @@ resume:
             senmode = ckt->CKTsenInfo->SENmode;
             save = ckt->CKTmode;
             ckt->CKTsenInfo->SENmode = DCSEN;
-            if(error = CKTsenDCtran(ckt)) return (error);
+            error = CKTsenDCtran(ckt);
+            if (error)
+                return(error);
+
             ckt->CKTmode = save;
             ckt->CKTsenInfo->SENmode = senmode;
 
diff --git a/src/spicelib/parser/inp2dot.c b/src/spicelib/parser/inp2dot.c
index 206c534ba..37fbe0297 100644
--- a/src/spicelib/parser/inp2dot.c
+++ b/src/spicelib/parser/inp2dot.c
@@ -567,6 +567,8 @@ dot_sens2(char *line, CKTcircuit *ckt, INPtables *tab, card *current,
 	int i;			/* generic loop variable */
 	char *token;		/* a token from the line */
 
+	NG_IGNORE(gnode);
+
 	/* .sens {AC} {DC} {TRAN} [dev=nnn parm=nnn]* */
 	which = -1;
 	for (i = 0; i < ft_sim->numAnalyses; i++) {
diff --git a/src/unsupported/Makefile.am b/src/unsupported/Makefile.am
new file mode 100644
index 000000000..d54234be8
--- /dev/null
+++ b/src/unsupported/Makefile.am
@@ -0,0 +1,22 @@
+## Process this file with automake to produce Makefile.in
+
+EXTRA_DIST = readme spiced.c
+
+noinst_LTLIBRARIES = libunsupported.la
+
+libunsupported_la_SOURCES = \
+	cktsenac.c		\
+	cktsenup.c		\
+	cktsncom.c		\
+	cktsndct.c		\
+	cktsnset.c		\
+	cktsnld.c		\
+	sen2dest.c		\
+	sen2setp.c		\
+	snaskq.c		\
+	snstart.c
+
+
+AM_CPPFLAGS = @AM_CPPFLAGS@ -I$(top_srcdir)/src/include
+AM_CFLAGS = $(STATIC)
+MAINTAINERCLEANFILES = Makefile.in
diff --git a/src/unsupported/cktsenac.c b/src/unsupported/cktsenac.c
index 07b18e71a..609956d7d 100644
--- a/src/unsupported/cktsenac.c
+++ b/src/unsupported/cktsenac.c
@@ -5,7 +5,7 @@ Author: 1985 Thomas L. Quarles
 /*
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -20,8 +20,7 @@ Author: 1985 Thomas L. Quarles
  */
 
 int
-CKTsenAC(ckt)
-register CKTcircuit *ckt;
+CKTsenAC(CKTcircuit *ckt)
 {
     int error;
 
@@ -30,13 +29,17 @@ register CKTcircuit *ckt;
 #endif /* SENSDEBUG */
 
 
-    if(error = CKTsenLoad(ckt)) return(error);
+    error = CKTsenLoad(ckt);
+    if (error)
+        return(error);
 
 #ifdef SENSDEBUG
     printf("after CKTsenLoad\n");
 #endif /* SENSDEBUG */
 
-    if(error = CKTsenComp(ckt)) return(error);
+    error = CKTsenComp(ckt);
+    if (error)
+        return(error);
 
 #ifdef SENSDEBUG
     printf("after CKTsenComp\n");
diff --git a/src/unsupported/cktsenup.c b/src/unsupported/cktsenup.c
index 830370f4c..32c17430e 100644
--- a/src/unsupported/cktsenup.c
+++ b/src/unsupported/cktsenup.c
@@ -11,7 +11,7 @@ Author: 1985 Thomas L. Quarles
  * in the given circuit 
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -22,10 +22,9 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-CKTsenUpdate(ckt)
-register CKTcircuit *ckt;
+CKTsenUpdate(CKTcircuit *ckt)
 {
-    register int i;
+    int i;
     int error;
 
 
diff --git a/src/unsupported/cktsncom.c b/src/unsupported/cktsncom.c
index 619b31f40..9b90f6eb2 100644
--- a/src/unsupported/cktsncom.c
+++ b/src/unsupported/cktsncom.c
@@ -10,7 +10,7 @@ Author: 1985 Thomas L. Quarles
  * of the given circuit 
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -21,10 +21,9 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-CKTsenComp(ckt)
-register CKTcircuit *ckt;
+CKTsenComp(CKTcircuit *ckt)
 {
-    register int size;
+    int size;
     int row;
     int col;
     SENstruct *info;
diff --git a/src/unsupported/cktsndct.c b/src/unsupported/cktsndct.c
index 195c0e7be..4cd70ba96 100644
--- a/src/unsupported/cktsndct.c
+++ b/src/unsupported/cktsndct.c
@@ -10,7 +10,7 @@ Author: 1985 Thomas L. Quarles
  * calculations
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -21,8 +21,7 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-CKTsenDCtran(ckt)
-register CKTcircuit *ckt;
+CKTsenDCtran(CKTcircuit *ckt)
 {
     int error;
 
diff --git a/src/unsupported/cktsnld.c b/src/unsupported/cktsnld.c
index 57e7ce436..051d5dc71 100644
--- a/src/unsupported/cktsnld.c
+++ b/src/unsupported/cktsnld.c
@@ -12,7 +12,7 @@ Author: 1985 Thomas L. Quarles
  * in the given circuit 
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -23,10 +23,9 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-CKTsenLoad(ckt)
-register CKTcircuit *ckt;
+CKTsenLoad(CKTcircuit *ckt)
 {
-    register int i;
+    int i;
     int size,row,col;
     int error;
 
diff --git a/src/unsupported/cktsnprt.c b/src/unsupported/cktsnprt.c
index fb6b1b3c6..35c7d91dd 100644
--- a/src/unsupported/cktsnprt.c
+++ b/src/unsupported/cktsnprt.c
@@ -5,7 +5,7 @@ Author: 1985 Thomas L. Quarles
 /*
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -22,10 +22,9 @@ Author: 1985 Thomas L. Quarles
      */
 
 void
-CKTsenPrint(ckt)
-register CKTcircuit *ckt;
+CKTsenPrint(CKTcircuit *ckt)
 {
-    register int i;
+    int i;
 
     for (i=0;i<DEVmaxnum;i++) {
         if ( DEVices[i]->DEVsenPrint && ckt->CKThead[i] ) {
diff --git a/src/unsupported/cktsnset.c b/src/unsupported/cktsnset.c
index 2cb344b60..5faeeb03a 100644
--- a/src/unsupported/cktsnset.c
+++ b/src/unsupported/cktsnset.c
@@ -13,7 +13,7 @@ Author: 1985 Thomas L. Quarles
  * in the given circuit 
  */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/smpdefs.h"
 #include "ngspice/cktdefs.h"
@@ -24,13 +24,11 @@ Author: 1985 Thomas L. Quarles
 
 
 int
-CKTsenSetup(ckt)
-register CKTcircuit *ckt;
-
+CKTsenSetup(CKTcircuit *ckt)
 {
-    register int i;
+    int i;
     int error;
-    register SENstruct *info;
+    SENstruct *info;
 #ifdef SENSDEBUG
     printf("CKTsenSetup\n");
 #endif /* SENSDEBUG */
diff --git a/src/unsupported/sen2dest.c b/src/unsupported/sen2dest.c
index 583871016..141019b00 100644
--- a/src/unsupported/sen2dest.c
+++ b/src/unsupported/sen2dest.c
@@ -9,20 +9,18 @@ Author: 1985 Thomas L. Quarles
      * given circuit 
      */
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/cktdefs.h"
 #include "ngspice/devdefs.h"
-#include "util.h"
 #include "ngspice/ifsim.h"
 #include "ngspice/sperror.h"
 #include "ngspice/suffix.h"
 
 void
-SENdestroy(info)
-    SENstruct *info;
+SENdestroy(SENstruct *info)
 {
-    register int i;
+    int i;
     int size;
 
 
diff --git a/src/unsupported/sen2setp.c b/src/unsupported/sen2setp.c
index b407e3b4d..eac9e2ed6 100644
--- a/src/unsupported/sen2setp.c
+++ b/src/unsupported/sen2setp.c
@@ -3,23 +3,21 @@ Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
 **********/
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/ifsim.h"
 #include "ngspice/iferrmsg.h"
 #include "ngspice/sen2defs.h"
 #include "ngspice/cktdefs.h"
-#include "util.h"
 #include "ngspice/suffix.h"
+#include "../spicelib/analysis/analysis.h"
 
 /* ARGSUSED */
 int 
-SENsetParm(ckt,anal,which,value)
-    CKTcircuit *ckt;
-    JOB *anal;
-    int which;
-    IFvalue *value;
+SENsetParm(CKTcircuit *ckt, JOB *anal, int which, IFvalue *value)
 {
+    NG_IGNORE(ckt);
+
     switch(which) {
 
     case SEN_DC:
diff --git a/src/unsupported/snaskq.c b/src/unsupported/snaskq.c
index ddaf0d75c..e253e5b4f 100644
--- a/src/unsupported/snaskq.c
+++ b/src/unsupported/snaskq.c
@@ -3,7 +3,7 @@ Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
 **********/
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/ifsim.h"
 #include "ngspice/iferrmsg.h"
@@ -13,12 +13,12 @@ Author: 1985 Thomas L. Quarles
 
 /* ARGSUSED */
 int 
-SENaskQuest(ckt,anal,which,value)
-    CKTcircuit *ckt;
-    JOB *anal;
-    int which;
-    IFvalue *value;
+SENaskQuest(CKTcircuit *ckt, JOB *anal, int which, IFvalue *value)
 {
+    NG_IGNORE(ckt);
+    NG_IGNORE(anal);
+    NG_IGNORE(value);
+
     switch(which) {
 
     default:
diff --git a/src/unsupported/snstart.c b/src/unsupported/snstart.c
index 79449259c..3092e78d9 100644
--- a/src/unsupported/snstart.c
+++ b/src/unsupported/snstart.c
@@ -3,11 +3,10 @@ Copyright 1990 Regents of the University of California.  All rights reserved.
 Author: 1985 Thomas L. Quarles
 **********/
 
-#include "spice.h"
+#include "ngspice/ngspice.h"
 #include <stdio.h>
 #include "ngspice/ifsim.h"
 #include "ngspice/cktdefs.h"
-#include "util.h"
 #include "ngspice/const.h"
 #include "ngspice/sperror.h"
 #include "ngspice/suffix.h"
@@ -17,8 +16,7 @@ Author: 1985 Thomas L. Quarles
  */
 
 int
-SENstartup(ckt)
-    CKTcircuit *ckt;
+SENstartup(CKTcircuit *ckt, int restart)
 {
     int i;
     int err;
@@ -26,6 +24,11 @@ SENstartup(ckt)
     int type;
     GENinstance *fast;
 
+    if (restart) {
+        fprintf(stderr, "unsupported code, (SENstartup), doesn't support restart\n");
+        exit(1);
+    }
+
 #ifdef SENSDEBUG 
     printf("SENstartup\n");
 #endif /* SENSDEBUG */ 
@@ -38,7 +41,7 @@ SENstartup(ckt)
     for(i=0;i<ckt->CKTsenInfo->SENnumVal;i++) {
         type = -1;
         fast = NULL;
-        err = CKTfndDev((GENERIC*)ckt,&type,(GENERIC**)&fast,
+        err = CKTfndDev(ckt, &type, &fast,
             ((ckt->CKTsenInfo->SENdevices)[i]), 
             NULL, NULL);
         if(err != OK) return(err);