diff --git a/ext2sim/ext2sim.c b/ext2sim/ext2sim.c
index 507dd1ea..2778ad0f 100644
--- a/ext2sim/ext2sim.c
+++ b/ext2sim/ext2sim.c
@@ -446,7 +446,7 @@ CmdExtToSim(w, cmd)
 	case EXTTOSIM_DEFAULT:
 	    LocCapThreshold = 2;
 	    LocResistThreshold = 10;
-	    EFTrimFlags = 0;
+	    EFOutputFlags = 0;
 	    EFScale = 0.0;
 	    if (EFArgTech)
 	    {
@@ -1307,8 +1307,8 @@ FILE *outf;
     suf = EFHNToStr(suffix);
     if (fetInfo[type].defSubs && strcasecmp(suf,fetInfo[type].defSubs) == 0) {
     	l = strlen(suf) - 1;
-	if (  ( EFTrimFlags & EF_TRIMGLOB ) && suf[l] =='!' ||
-	      ( EFTrimFlags & EF_TRIMLOCAL ) && suf[l] == '#'  )
+	if (  ( EFOutputFlags & EF_TRIMGLOB ) && suf[l] =='!' ||
+	      ( EFOutputFlags & EF_TRIMLOCAL ) && suf[l] == '#'  )
 	      suf[l] = '\0' ;
 	if ( esFormat == SU )
 		fprintf(outf, "S_");
diff --git a/ext2spice/ext2hier.c b/ext2spice/ext2hier.c
index 717dadc9..390937e0 100644
--- a/ext2spice/ext2hier.c
+++ b/ext2spice/ext2hier.c
@@ -555,7 +555,8 @@ spcdevHierVisit(hc, dev, scale)
 	case DEV_RES:
 	case DEV_CAP:
 	case DEV_CAPREV:
-	    if (dev->dev_type == esNoModelType)
+	    if ((dev->dev_type == esNoModelType) ||
+		    !strcmp(EFDevTypes[dev->dev_type], "None"))
 		has_model = FALSE;
 	    break;
     }
@@ -601,6 +602,9 @@ spcdevHierVisit(hc, dev, scale)
 	case DEV_RES:
 	    devchar = 'R';
 	    break;
+	case DEV_VOLT:
+	    devchar = 'V';
+	    break;
 	case DEV_CAP:
 	case DEV_CAPREV:
 	    devchar = 'C';
@@ -638,6 +642,9 @@ spcdevHierVisit(hc, dev, scale)
 	    case DEV_CAPREV:
 		fprintf(esSpiceF, "%d", esCapNum++);
 		break;
+	    case DEV_VOLT:
+		fprintf(esSpiceF, "%d", esVoltNum++);
+		break;
 	    case DEV_SUBCKT:
 	    case DEV_RSUBCKT:
 	    case DEV_CSUBCKT:
@@ -792,6 +799,21 @@ spcdevHierVisit(hc, dev, scale)
 	    }
 	    break;
 
+	case DEV_VOLT:
+	    /* Voltage source is "Vnnn term1 term2 0.0".  It is used only to
+	     * separate port names that have been shorted.
+	     */
+	    if (dev->dev_nterm > 1)
+		spcdevOutNode(hc->hc_hierName,
+			source->dterm_node->efnode_name->efnn_hier,
+			"plus", esSpiceF);
+	    if (dev->dev_nterm > 2)
+		spcdevOutNode(hc->hc_hierName,
+			drain->dterm_node->efnode_name->efnn_hier,
+			"minus", esSpiceF);
+	    fprintf(esSpiceF, " 0.0");
+	    break;
+
 	case DEV_DIODE:
 	case DEV_PDIODE:
 	    if (source == NULL) break;
@@ -1083,7 +1105,8 @@ spcdevHierMergeVisit(hc, dev, scale)
 		    break;
 		case DEV_RSUBCKT:
 		case DEV_RES:
-		    if (fp->dev->dev_type == esNoModelType)
+		    if ((fp->dev->dev_type == esNoModelType) ||
+			    !strcmp(EFDevTypes[fp->dev->dev_type], "None"))
 			m = esFMult[cfp->esFMIndex] + (fp->dev->dev_res
 				/ cfp->dev->dev_res);
 		    else
@@ -1092,7 +1115,8 @@ spcdevHierMergeVisit(hc, dev, scale)
 		case DEV_CSUBCKT:
 		case DEV_CAP:
 		case DEV_CAPREV:
-		    if (fp->dev->dev_type == esNoModelType)
+		    if ((fp->dev->dev_type == esNoModelType) ||
+			    !strcmp(EFDevTypes[fp->dev->dev_type], "None"))
 			m = esFMult[cfp->esFMIndex] + (fp->dev->dev_cap
 				/ cfp->dev->dev_cap);
 		    else
@@ -1481,7 +1505,8 @@ mergeThem:
 		    break;
 		case DEV_RSUBCKT:
 		case DEV_RES:
-		    if (fp->dev->dev_type == esNoModelType)
+		    if ((fp->dev->dev_type == esNoModelType) ||
+			    !strcmp(EFDevTypes[fp->dev->dev_type], "None"))
 		        m = esFMult[cfp->esFMIndex] + (fp->dev->dev_res
 				/ cfp->dev->dev_res);
 		    else
@@ -1490,7 +1515,8 @@ mergeThem:
 		case DEV_CSUBCKT:
 		case DEV_CAP:
 		case DEV_CAPREV:
-		    if (fp->dev->dev_type == esNoModelType)
+		    if ((fp->dev->dev_type == esNoModelType) ||
+			    !strcmp(EFDevTypes[fp->dev->dev_type], "None"))
 		        m = esFMult[cfp->esFMIndex] + (fp->dev->dev_cap
 				/ cfp->dev->dev_cap);
 		    else
diff --git a/ext2spice/ext2spice.c b/ext2spice/ext2spice.c
index bd7aaf81..8205abfd 100644
--- a/ext2spice/ext2spice.c
+++ b/ext2spice/ext2spice.c
@@ -65,7 +65,7 @@ float esScale = -1.0 ; /* negative if hspice the EFScale/100 otherwise */
 
 unsigned short esFormat = SPICE3 ;
 
-int esCapNum, esDevNum, esResNum, esDiodeNum;
+int esCapNum, esDevNum, esResNum, esDiodeNum, esVoltNum;
 int esNodeNum;  /* just in case we're extracting spice2 */
 int esSbckNum; 	/* used in hspice node name shortening   */
 int esNoModelType;  /* index for device type "None" (model-less device) */
@@ -137,20 +137,20 @@ esFormatSubs(outf, suf)
     if (outf)
     {
 	l = strlen(suf) - 1;
-	if ((EFTrimFlags & EF_TRIMGLOB ) && suf[l] == '!' ||
-	         (EFTrimFlags & EF_TRIMLOCAL) && suf[l] == '#')
+	if ((EFOutputFlags & EF_TRIMGLOB ) && suf[l] == '!' ||
+	         (EFOutputFlags & EF_TRIMLOCAL) && suf[l] == '#')
 	    suf[l] = '\0' ;
-	if (EFTrimFlags & EF_CONVERTCOMMA)
+	if (EFOutputFlags & EF_CONVERTCOMMA)
 	    while ((specchar = strchr(suf, ',')) != NULL)
 		*specchar = '|';
-	if (EFTrimFlags & EF_CONVERTBRACKETS)
+	if (EFOutputFlags & EF_CONVERTBRACKETS)
 	{
 	    while ((specchar = strchr(suf, '[')) != NULL)
 		*specchar = '_';
 	    while ((specchar = strchr(suf, ']')) != NULL)
 		*specchar = '_';
 	}
-	if (EFTrimFlags & EF_CONVERTEQUAL)
+	if (EFOutputFlags & EF_CONVERTEQUAL)
 	    while ((specchar = strchr(suf, '=')) != NULL)
 		*specchar = ':';
 	fprintf(outf, "%s", suf);
@@ -213,13 +213,14 @@ Exttospice_Init(interp)
 #define EXTTOSPC_EXTRESIST	6
 #define EXTTOSPC_RESISTORTEE	7
 #define EXTTOSPC_SCALE		8
-#define EXTTOSPC_SUBCIRCUITS	9
-#define EXTTOSPC_HIERARCHY	10
-#define EXTTOSPC_BLACKBOX	11
-#define EXTTOSPC_RENUMBER	12
-#define EXTTOSPC_MERGENAMES	13
-#define EXTTOSPC_LVS		14
-#define EXTTOSPC_HELP		15
+#define EXTTOSPC_SHORT		9
+#define EXTTOSPC_SUBCIRCUITS	10
+#define EXTTOSPC_HIERARCHY	11
+#define EXTTOSPC_BLACKBOX	12
+#define EXTTOSPC_RENUMBER	13
+#define EXTTOSPC_MERGENAMES	14
+#define EXTTOSPC_LVS		15
+#define EXTTOSPC_HELP		16
 
 void
 CmdExtToSpice(w, cmd)
@@ -264,6 +265,8 @@ CmdExtToSpice(w, cmd)
 	"extresist [on|off]	incorporate information from extresist",
 	"resistor tee [on|off]	model resistor capacitance as a T-network",
 	"scale [on|off]		use .option card for scaling",
+	"short [voltage|resistor|none]\n"
+	"			set method for handling shorted ports",
 	"subcircuits [top|descend] [on|off|auto]\n"
 	"			standard cells become subcircuit calls",
 	"hierarchy [on|off]	output hierarchical spice for LVS",
@@ -283,6 +286,12 @@ CmdExtToSpice(w, cmd)
 	NULL
     };
 
+    static char *cmdShortTypes[] = {
+	"none			merge shorted ports",
+	"resistor		separate shorted ports with 0 ohm resistor",
+	"voltage		separate shorted ports with 0 volt source",
+	NULL
+    };
     static char *cmdExtToSpcFormat[] = {
 	"spice2",
 	"spice3",
@@ -314,6 +323,13 @@ CmdExtToSpice(w, cmd)
 	NULL
     };
 
+    static char *shorttypes[] = {
+	"none",
+	"resistor",
+	"voltage",
+	NULL
+    };
+
     typedef enum {
 	IDX_YES, IDX_TRUE, IDX_ON, IDX_NO, IDX_FALSE, IDX_OFF,
 	IDX_AUTO, IDX_TOP, IDX_DESCEND
@@ -428,6 +444,36 @@ CmdExtToSpice(w, cmd)
 		esMergeNames = FALSE;
 	    break;
 
+	case EXTTOSPC_SHORT:
+	    if (cmd->tx_argc == 2)
+	    {
+		if ((EFOutputFlags & EF_SHORT_MASK) == EF_SHORT_NONE)
+		    Tcl_SetResult(magicinterp, "none", NULL);
+		else if ((EFOutputFlags & EF_SHORT_MASK) == EF_SHORT_R)
+		    Tcl_SetResult(magicinterp, "resistor", NULL);
+		else if ((EFOutputFlags & EF_SHORT_MASK) == EF_SHORT_V)
+		    Tcl_SetResult(magicinterp, "voltage source", NULL);
+		return;
+	    }
+	    idx = Lookup(cmd->tx_argv[2], cmdShortTypes);
+	    if (idx < 0) goto usage;
+	    else switch (idx)
+	    {
+		case 0:
+		    EFOutputFlags &= ~EF_SHORT_MASK;
+		    EFOutputFlags |= EF_SHORT_NONE;
+		    break;
+		case 1:
+		    EFOutputFlags &= ~EF_SHORT_MASK;
+		    EFOutputFlags |= EF_SHORT_R;
+		    break;
+		case 2:
+		    EFOutputFlags &= ~EF_SHORT_MASK;
+		    EFOutputFlags |= EF_SHORT_V;
+		    break;
+	    }
+	    break;
+
 	case EXTTOSPC_LVS:
 	    /* Apply default command settings for LVS */
 	    /* hierarchy = on		*/
@@ -615,7 +661,7 @@ CmdExtToSpice(w, cmd)
 	case EXTTOSPC_DEFAULT:
 	    LocCapThreshold = 2;
 	    LocResistThreshold = INFINITE_THRESHOLD;
-	    EFTrimFlags = EF_CONVERTCOMMA | EF_CONVERTEQUAL;
+	    EFOutputFlags = EF_CONVERTCOMMA | EF_CONVERTEQUAL;
 	    EFScale = 0.0;
 	    if (EFArgTech)
 	    {
@@ -647,6 +693,7 @@ runexttospice:
 
     /* Reset the device indices */
     esCapNum  = 0;
+    esVoltNum  = 0;
     esDevNum = 1000;
     esResNum = 0;
     esDiodeNum = 0;
@@ -832,10 +879,10 @@ runexttospice:
 
     // This forces options TRIMGLOB and CONVERTEQUAL, not sure that's such a
     // good idea. . .
-    EFTrimFlags |= EF_TRIMGLOB | EF_CONVERTEQUAL | EF_CONVERTCOMMA;
+    EFOutputFlags |= EF_TRIMGLOB | EF_CONVERTEQUAL | EF_CONVERTCOMMA;
     if (IS_FINITE_F(EFCapThreshold)) flatFlags |= EF_FLATCAPS;
     if (esFormat == HSPICE)
-	EFTrimFlags |= EF_TRIMLOCAL;
+	EFOutputFlags |= EF_TRIMLOCAL;
 
     /* Write globals under a ".global" card */
 
@@ -1054,10 +1101,10 @@ main(argc, argv)
 
     /* Convert the hierarchical description to a flat one */
     flatFlags = EF_FLATNODES;
-    EFTrimFlags |= EF_TRIMGLOB ;
+    EFOutputFlags |= EF_TRIMGLOB ;
     if (IS_FINITE_F(EFCapThreshold)) flatFlags |= EF_FLATCAPS;
     if (esFormat == HSPICE) {
-	EFTrimFlags |= EF_TRIMLOCAL ;
+	EFOutputFlags |= EF_TRIMLOCAL ;
 	HashInit(&subcktNameTable, 32, HT_STRINGKEYS);
 #ifndef UNSORTED_SUBCKT
 	DQInit(&subcktNameQueue, 64);
@@ -1392,14 +1439,14 @@ subcktVisit(use, hierName, is_top)
     }
     else
     {
-	int savflags = EFTrimFlags;
-	EFTrimFlags = EF_CONVERTCOMMA;	// Only substitute commas on subcircuit names
+	int savflags = EFOutputFlags;
+	EFOutputFlags = EF_CONVERTCOMMA;	// Only substitute commas on subcircuit names
 
 	/* Use full hierarchical decomposition for name */
 	/* (not just use->use_id.  hierName already has use->use_id at end) */
 	EFHNSprintf(stmp, hierName);
 	fprintf(esSpiceF, "X%s", stmp);
-	EFTrimFlags = savflags;
+	EFOutputFlags = savflags;
 	tchars = 1 + strlen(stmp);
     }
 
@@ -2393,7 +2440,8 @@ spcdevVisit(dev, hc, scale, trans)
 	case DEV_CAPREV:
 	    if (dev->dev_nterm < 1)
 		return 0;
-	    if (dev->dev_type == esNoModelType)
+	    if ((dev->dev_type == esNoModelType) ||
+		    !strcmp(EFDevTypes[dev->dev_type], "None"))
 		has_model = FALSE;
 	    break;
     }
@@ -2439,6 +2487,9 @@ spcdevVisit(dev, hc, scale, trans)
 	case DEV_RES:
 	    devchar = 'R';
 	    break;
+	case DEV_VOLT:
+	    devchar = 'V';
+	    break;
 	case DEV_CAP:
 	case DEV_CAPREV:
 	    devchar = 'C';
@@ -2480,6 +2531,9 @@ spcdevVisit(dev, hc, scale, trans)
 	    case DEV_CAPREV:
 		fprintf(esSpiceF, "%d", esCapNum++);
 		break;
+	    case DEV_VOLT:
+		fprintf(esSpiceF, "%d", esVoltNum++);
+		break;
 	    case DEV_SUBCKT:
 	    case DEV_RSUBCKT:
 	    case DEV_CSUBCKT:
@@ -2631,6 +2685,19 @@ spcdevVisit(dev, hc, scale, trans)
 	    }
 	    break;
 
+	case DEV_VOLT:
+	    /* The voltage source is "Vnnn term1 term2 0.0" and is used
+	     * only to separate shorted port names.
+	     */
+	    if (dev->dev_nterm > 1)
+		spcdevOutNode(hierName, source->dterm_node->efnode_name->efnn_hier,
+			name, esSpiceF);
+	    if (dev->dev_nterm > 1)
+		spcdevOutNode(hierName, drain->dterm_node->efnode_name->efnn_hier,
+			name, esSpiceF);
+	    fprintf(esSpiceF, " 0.0");
+	    break;
+
 	case DEV_DIODE:
 	case DEV_PDIODE:
 
@@ -3408,7 +3475,7 @@ retName:
  * EFHNSprintf --
  *
  * Create a hierarchical node name.
- * The flags in EFTrimFlags control whether global (!) or local (#)
+ * The flags in EFOutputFlags control whether global (!) or local (#)
  * suffixes are to be trimmed. Also substitutes \. with \@ if the
  * format is hspice.
  *
@@ -3432,14 +3499,14 @@ EFHNSprintf(str, hierName)
 
     s = str;
     if (hierName->hn_parent) str = efHNSprintfPrefix(hierName->hn_parent, str);
-    if (EFTrimFlags)
+    if (EFOutputFlags)
     {
 	cp = hierName->hn_name;
-	trimGlob = (EFTrimFlags & EF_TRIMGLOB);
-	trimLocal = (EFTrimFlags & EF_TRIMLOCAL);
-	convertComma = (EFTrimFlags & EF_CONVERTCOMMA);
-	convertEqual = (EFTrimFlags & EF_CONVERTEQUAL);
-	convertBrackets = (EFTrimFlags & EF_CONVERTBRACKETS);
+	trimGlob = (EFOutputFlags & EF_TRIMGLOB);
+	trimLocal = (EFOutputFlags & EF_TRIMLOCAL);
+	convertComma = (EFOutputFlags & EF_CONVERTCOMMA);
+	convertEqual = (EFOutputFlags & EF_CONVERTEQUAL);
+	convertBrackets = (EFOutputFlags & EF_CONVERTBRACKETS);
 	while (c = *cp++)
 	{
 	    switch (c)
@@ -3465,9 +3532,9 @@ char *efHNSprintfPrefix(hierName, str)
     char *str;
 {
     char *cp, c;
-    bool convertEqual = (EFTrimFlags & EF_CONVERTEQUAL) ? TRUE : FALSE;
-    bool convertComma = (EFTrimFlags & EF_CONVERTCOMMA) ? TRUE : FALSE;
-    bool convertBrackets = (EFTrimFlags & EF_CONVERTBRACKETS) ? TRUE : FALSE;
+    bool convertEqual = (EFOutputFlags & EF_CONVERTEQUAL) ? TRUE : FALSE;
+    bool convertComma = (EFOutputFlags & EF_CONVERTCOMMA) ? TRUE : FALSE;
+    bool convertBrackets = (EFOutputFlags & EF_CONVERTBRACKETS) ? TRUE : FALSE;
 
     if (hierName->hn_parent)
 	str = efHNSprintfPrefix(hierName->hn_parent, str);
@@ -3750,6 +3817,9 @@ parallelDevs(f1, f2)
 	case DEV_RSUBCKT:
 	case DEV_CSUBCKT:
 	    break;
+
+	case DEV_VOLT:
+	    break;
     }
     return NOT_PARALLEL;
 }
diff --git a/ext2spice/ext2spice.h b/ext2spice/ext2spice.h
index 4a30d847..d8abf44c 100644
--- a/ext2spice/ext2spice.h
+++ b/ext2spice/ext2spice.h
@@ -62,7 +62,7 @@ extern float esScale;	/* negative if hspice the EFScale/100 otherwise */
 extern unsigned short esFormat;
 extern TileTypeBitMask initMask;
 
-extern int esCapNum, esDevNum, esResNum, esDiodeNum;
+extern int esCapNum, esDevNum, esResNum, esDiodeNum, esVoltNum;
 extern int esNodeNum;  /* just in case we're extracting spice2 */
 extern int esSbckNum; 	/* used in hspice node name shortening   */
 extern int esNoModelType;  /* index for device type "None" (model-less device) */
@@ -144,8 +144,6 @@ typedef struct {
 	TTMaskZero (&((nodeClientHier *) (node)->efnode_client)->m_w.visitMask); \
 }
 
-
-
 /* attributes controlling the Area/Perimeter extraction of dev terminals */
 #define ATTR_FLATAP	"*[Ee][Xx][Tt]:[Aa][Pp][Ff]*"
 #define ATTR_HIERAP	"*[Ee][Xx][Tt]:[Aa][Pp][Hh]*"
diff --git a/extflat/EFargs.c b/extflat/EFargs.c
index 4e5d6982..7c6a9f39 100644
--- a/extflat/EFargs.c
+++ b/extflat/EFargs.c
@@ -43,7 +43,7 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
     /* Command-line flags */
 EFCapValue EFCapThreshold = 2;  /* -c/-C: (fF) smallest interesting C */
 int EFResistThreshold = 10;	/* -r/-R: (Ohms) smallest interesting R */
-int EFTrimFlags = 0;		/* -t: output of nodename trailing #!'s */
+int EFOutputFlags = 0;		/* -t: output of nodename trailing #!'s */
 char *EFSearchPath = NULL;	/* -p: Search path for .ext files */
 char *EFArgTech = NULL;		/* -T: Tech specified on command line */
 
@@ -216,12 +216,12 @@ EFArgs(argc, argv, err_result, argsProc, cdata)
 	    case 't':
 		if ((cp = ArgStr(&argc, &argv, "trim characters")) == NULL)
 		    goto usage;
-		if (strchr(cp, '!')) EFTrimFlags |= EF_TRIMGLOB;
-		if (strchr(cp, '#')) EFTrimFlags |= EF_TRIMLOCAL;
-		if (strchr(cp, ',')) EFTrimFlags |= EF_CONVERTCOMMA;
-		if (strchr(cp, '=')) EFTrimFlags |= EF_CONVERTEQUAL;
-		if (strchr(cp, '[')) EFTrimFlags |= EF_CONVERTBRACKETS;
-		if (strchr(cp, ']')) EFTrimFlags |= EF_CONVERTBRACKETS;
+		if (strchr(cp, '!')) EFOutputFlags |= EF_TRIMGLOB;
+		if (strchr(cp, '#')) EFOutputFlags |= EF_TRIMLOCAL;
+		if (strchr(cp, ',')) EFOutputFlags |= EF_CONVERTCOMMA;
+		if (strchr(cp, '=')) EFOutputFlags |= EF_CONVERTEQUAL;
+		if (strchr(cp, '[')) EFOutputFlags |= EF_CONVERTBRACKETS;
+		if (strchr(cp, ']')) EFOutputFlags |= EF_CONVERTBRACKETS;
 		break;
 	    case 'C':
 		EFCapThreshold = (EFCapValue)INFINITE_THRESHOLD_F;
diff --git a/extflat/EFbuild.c b/extflat/EFbuild.c
index 07d59fdd..976b3bd5 100644
--- a/extflat/EFbuild.c
+++ b/extflat/EFbuild.c
@@ -479,6 +479,35 @@ efBuildEquiv(def, nodeName1, nodeName2)
     else if (nn2->efnn_node == (EFNode *)NULL)
 	return;		/* Repeated "equiv" statement */
 
+    /* If both names exist and are for different ports, then keep   */
+    /* them separate and add a zero ohm resistor or a zero volt	    */
+    /* source between them, based on the method set by "ext2spice   */
+    /* shorts".							    */
+
+    if (nn1 && nn2 && (nn1->efnn_port >= 0) && (nn2->efnn_port >= 0) &&
+	    (nn1->efnn_port != nn2->efnn_port))
+    {
+	if ((EFOutputFlags & EF_SHORT_MASK) != EF_SHORT_NONE)
+	{
+	    int i;
+	    int sdev;
+	    char *argv[7], zeroarg[] = "0";
+
+	    if ((EFOutputFlags & EF_SHORT_MASK) == EF_SHORT_R)
+		sdev = DEV_RES;
+	    else
+		sdev = DEV_VOLT;
+
+	    for (i = 0; i < 10; i++) argv[i] = zeroarg;
+	    argv[4] = StrDup((char **)NULL, nodeName1);
+	    argv[7] = StrDup((char **)NULL, nodeName2);
+	    efBuildDevice(def, sdev, "None", &GeoNullRect, 10, argv);
+	    freeMagic(argv[4]);
+	    freeMagic(argv[7]);
+	    return;
+	}
+    }
+
     /* If both names exist and are for different nodes, merge them */
     if (nn1)
     {
@@ -813,9 +842,24 @@ efBuildDevice(def, class, type, r, argc, argv)
      */
     
     ttype = extGetDevType(type);
+    if (ttype < 0)
+    {
+	/* For zero-ohm resistors used to separate ports on the same	*/
+	/* net, generate a unique devhash.				*/
+	ttype = DBNumTypes;
+	while (1)
+	{
+	    sprintf(devhash, "%dx%d_%d", r->r_xbot, r->r_ybot, ttype);
+	    he = HashLookOnly(&def->def_devs, devhash);
+	    if (he == NULL) break;
+	    ttype++;
+	}
+    }
+
     sprintf(devhash, "%dx%d_%d", r->r_xbot, r->r_ybot, ttype);
     he = HashFind(&def->def_devs, devhash);
     newdev = (Dev *)HashGetValue(he);
+
     if (newdev)
     {
 	/* Duplicate device.  Duplicates will only appear in res.ext files
diff --git a/extflat/EFread.c b/extflat/EFread.c
index 714c3604..3404e5f7 100644
--- a/extflat/EFread.c
+++ b/extflat/EFread.c
@@ -44,8 +44,8 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 #ifndef MAGIC_WRAPPER
 /* This must match the definition for extDevTable in extract/ExtBasic.c */
 char *extDevTable[] = {"fet", "mosfet", "asymmetric", "bjt", "devres",
-		"devcap", "devcaprev", "diode", "pdiode", "ndiode",
-		"subckt", "rsubckt", "msubckt", "csubckt", NULL};
+		"devcap", "devcaprev", "vsource", "diode", "pdiode",
+		"ndiode", "subckt", "rsubckt", "msubckt", "csubckt", NULL};
 #endif
 
 /*
diff --git a/extflat/EFvisit.c b/extflat/EFvisit.c
index a556abe7..dd68ce9c 100644
--- a/extflat/EFvisit.c
+++ b/extflat/EFvisit.c
@@ -847,7 +847,7 @@ EFLookDist(hn1, hn2, pMinDist, pMaxDist)
  * EFHNOut --
  *
  * Output a hierarchical node name.
- * The flags in EFTrimFlags control whether global (!) or local (#)
+ * The flags in EFOutputFlags control whether global (!) or local (#)
  * suffixes are to be trimmed.
  *
  * Results:
@@ -868,13 +868,13 @@ EFHNOut(hierName, outf)
     char *cp, c;
 
     if (hierName->hn_parent) efHNOutPrefix(hierName->hn_parent, outf);
-    if (EFTrimFlags)
+    if (EFOutputFlags)
     {
 	cp = hierName->hn_name;
-	trimGlob = (EFTrimFlags & EF_TRIMGLOB);
-	trimLocal = (EFTrimFlags & EF_TRIMLOCAL);
-	convComma = (EFTrimFlags & EF_CONVERTCOMMA);
-	convBrackets = (EFTrimFlags & EF_CONVERTBRACKETS);
+	trimGlob = (EFOutputFlags & EF_TRIMGLOB);
+	trimLocal = (EFOutputFlags & EF_TRIMLOCAL);
+	convComma = (EFOutputFlags & EF_CONVERTCOMMA);
+	convBrackets = (EFOutputFlags & EF_CONVERTBRACKETS);
 	while (c = *cp++)
 	{
 	    if (*cp)
diff --git a/extflat/extflat.h b/extflat/extflat.h
index 56cc5554..3ae5bb37 100644
--- a/extflat/extflat.h
+++ b/extflat/extflat.h
@@ -37,13 +37,18 @@ typedef unsigned char U_char;
 #define	EF_NONAMEMERGE		0x20	/* Don't merge unconnected nets	*/
 					/* with the same name.		*/
 
-/* Flags to control output of node names.  Stored in EFTrimFlags */
+/* Flags to control output of node names.  Stored in EFOutputFlags */
 #define	EF_TRIMGLOB		0x01	/* Delete trailing '!' from names */
 #define	EF_TRIMLOCAL		0x02	/* Delete trailing '#' from names */
 #define EF_CONVERTCOMMA		0x04	/* Change ',' to '|' in names, else remove */
 #define EF_CONVERTEQUAL		0x08	/* Change '=' to ':' in names, else remove */
 #define EF_CONVERTBRACKETS	0x10	/* Change '[' and ']' to '_' in names */
 
+#define EF_SHORT_MASK		0x30	/* Mask for handling port shorts */
+#define EF_SHORT_NONE		0x00	/* Shorted ports are merged */
+#define EF_SHORT_R		0x10	/* Shorted ports separated with 0 ohm resistor */
+#define EF_SHORT_V		0x20	/* Shorted ports separated with 0 volt source */
+
 /*
  * capacitance type now set to float
  */
@@ -327,7 +332,7 @@ extern char *EFLayerNames[];
 extern int EFLayerNumNames;
 
     /* Output control flags */
-extern int EFTrimFlags;
+extern int EFOutputFlags;
 
 /* -------------------------- Exported procedures --------------------- */
 
diff --git a/extract/ExtBasic.c b/extract/ExtBasic.c
index 90d33753..73c0d355 100644
--- a/extract/ExtBasic.c
+++ b/extract/ExtBasic.c
@@ -55,8 +55,8 @@ static char sccsid[] = "@(#)ExtBasic.c	4.13 MAGIC (Berkeley) 12/5/85";
 
 #ifdef MAGIC_WRAPPER
 char *extDevTable[] = {"fet", "mosfet", "asymmetric", "bjt", "devres",
-	"devcap", "devcaprev", "diode", "pdiode", "ndiode", "subckt",
-	"rsubckt", "msubckt", "csubckt", NULL};
+	"devcap", "devcaprev", "vsource", "diode", "pdiode", "ndiode",
+	"subckt", "rsubckt", "msubckt", "csubckt", NULL};
 #endif
 
 /* --------------------- Data local to this file ---------------------- */
diff --git a/extract/extract.h b/extract/extract.h
index 29988449..84a73fff 100644
--- a/extract/extract.h
+++ b/extract/extract.h
@@ -46,13 +46,14 @@ extern int ExtDoWarn;		/* Bitmask of above */
 #define DEV_RES         4		/* Resistor */
 #define DEV_CAP         5		/* Capacitor */
 #define DEV_CAPREV      6		/* Capacitor, terminals reversed */
-#define DEV_DIODE	7		/* Diode */
-#define DEV_PDIODE	8		/* pDiode, same as Diode	*/
-#define DEV_NDIODE	9		/* nDiode, terminals reversed	*/
-#define DEV_SUBCKT     10		/* general-purpose subcircuit	*/
-#define DEV_RSUBCKT    11		/* Resistor-like subcircuit.	*/
-#define DEV_MSUBCKT    12		/* MOSFET-like subcircuit.	*/
-#define DEV_CSUBCKT    13		/* Capacitor-like subcircuit.	*/
+#define DEV_VOLT        7		/* Voltage source (used for shorts) */
+#define DEV_DIODE	8		/* Diode */
+#define DEV_PDIODE	9		/* pDiode, same as Diode	*/
+#define DEV_NDIODE     10		/* nDiode, terminals reversed	*/
+#define DEV_SUBCKT     11		/* general-purpose subcircuit	*/
+#define DEV_RSUBCKT    12		/* Resistor-like subcircuit.	*/
+#define DEV_MSUBCKT    13		/* MOSFET-like subcircuit.	*/
+#define DEV_CSUBCKT    14		/* Capacitor-like subcircuit.	*/
 
 /* Device names for .ext file output (new in version 7.2)	*/
 /* (defined in extract/ExtBasic.c *and* extflat/EFread.c)	*/
@@ -60,14 +61,15 @@ extern int ExtDoWarn;		/* Bitmask of above */
 extern char *extDevTable[];
 
 /* Extractor options */
-#define	EXT_DOADJUST		0x01	/* Extract hierarchical adjustments */
-#define	EXT_DOCAPACITANCE	0x02	/* Extract capacitance */
-#define	EXT_DOCOUPLING		0x04	/* Extract coupling capacitance */
-#define	EXT_DORESISTANCE	0x08	/* Extract resistance */
-#define	EXT_DOLENGTH		0x10	/* Extract pathlengths */
-#define	EXT_DOALL		0x1f	/* ALL OF THE ABOVE */
-#define	EXT_DOLOCAL		0x20	/* Write to local directory only */
-#define	EXT_DOLABELCHECK	0x40	/* Check for connections by label */
+
+#define	EXT_DOADJUST		0x001	/* Extract hierarchical adjustments */
+#define	EXT_DOCAPACITANCE	0x002	/* Extract capacitance */
+#define	EXT_DOCOUPLING		0x004	/* Extract coupling capacitance */
+#define	EXT_DORESISTANCE	0x008	/* Extract resistance */
+#define	EXT_DOLENGTH		0x010	/* Extract pathlengths */
+#define	EXT_DOALL		0x01f	/* ALL OF THE ABOVE */
+#define	EXT_DOLOCAL		0x020	/* Write to local directory only */
+#define	EXT_DOLABELCHECK	0x040	/* Check for connections by label */
 
 extern int ExtOptions;		/* Bitmask of above */