diff --git a/MotorDriver.cpp b/MotorDriver.cpp
index 61e229f..15b5607 100644
--- a/MotorDriver.cpp
+++ b/MotorDriver.cpp
@@ -605,6 +605,10 @@ void MotorDriver::checkPowerOverload(bool useProgLimit, byte trackno) {
 	DIAG(F("TRACK %c ALERT FAULT"), trackno + 'A');
       }
       setPower(POWERMODE::ALERT);
+      if (trackMode & (TRACK_MODE_MAIN|TRACK_MODE_EXT)){ // add (&& isAutoreverse) later
+	DIAG(F("TRACK %c INVERT"), trackno + 'A');
+	invertOutput();
+      }
       break;
     }
     // all well
diff --git a/MotorDriver.h b/MotorDriver.h
index 20a91d3..c6e06b8 100644
--- a/MotorDriver.h
+++ b/MotorDriver.h
@@ -148,7 +148,9 @@ class MotorDriver {
     // otherwise the call from interrupt context can undo whatever we do
     // from outside interrupt
     void setBrake( bool on, bool interruptContext=false);
-  __attribute__((always_inline)) inline void setSignal( bool high) {
+    __attribute__((always_inline)) inline void setSignal( bool high) {
+      if (invertPhase)
+	high = !high;
       if (trackPWM) {
 	DCCTimer::setPWM(signalPin,high);
       }
@@ -168,6 +170,12 @@ class MotorDriver {
 	pinMode(signalPin, OUTPUT);
       else
 	pinMode(signalPin, INPUT);
+      if (signalPin2 != UNUSED_PIN) {
+	if (on)
+	  pinMode(signalPin2, OUTPUT);
+	else
+	  pinMode(signalPin2, INPUT);
+      }
     };
     inline pinpair getSignalPin() { return pinpair(signalPin,signalPin2); };
     void setDCSignal(byte speedByte);
@@ -232,6 +240,32 @@ class MotorDriver {
 #endif
   inline void setMode(TRACK_MODE m) {
     trackMode = m;
+    invertOutput(trackMode & TRACK_MODE_DCX);// change later to TRACK_MODE_INVERTED?
+  };
+  inline void invertOutput() {               // toggles output inversion
+    invertPhase = !invertPhase;
+    invertOutput(invertPhase);
+  };
+  inline void invertOutput(bool b) {         // sets output inverted or not
+    if (b)
+      invertPhase = 1;
+    else
+      invertPhase = 0;
+#if defined(ARDUINO_ARCH_ESP32)
+    pinpair p = getSignalPin();
+    uint32_t *outreg = (uint32_t *)(GPIO_FUNC0_OUT_SEL_CFG_REG + 4*p.pin);
+    if (invertPhase) // set or clear the invert bit in the gpio out register
+      *outreg |=  ((uint32_t)0x1 << GPIO_FUNC0_OUT_INV_SEL_S);
+    else
+      *outreg &= ~((uint32_t)0x1 << GPIO_FUNC0_OUT_INV_SEL_S);
+    if (p.invpin != UNUSED_PIN) {
+      outreg = (uint32_t *)(GPIO_FUNC0_OUT_SEL_CFG_REG + 4*p.invpin);
+      if (invertPhase) // clear or set the invert bit in the gpio out register
+	*outreg &= ~((uint32_t)0x1 << GPIO_FUNC0_OUT_INV_SEL_S);
+      else
+	*outreg |=  ((uint32_t)0x1 << GPIO_FUNC0_OUT_INV_SEL_S);
+    }
+#endif
   };
   inline TRACK_MODE getMode() {
     return trackMode;
@@ -263,7 +297,7 @@ class MotorDriver {
     bool invertBrake;       // brake pin passed as negative means pin is inverted
     bool invertPower;       // power pin passed as negative means pin is inverted
     bool invertFault;       // fault pin passed as negative means pin is inverted
-    
+    bool invertPhase = 0;   // phase of out pin is inverted
     // Raw to milliamp conversion factors avoiding float data types.
     // Milliamps=rawADCreading * sensefactorInternal / senseScale
     //
diff --git a/TrackManager.cpp b/TrackManager.cpp
index dedf45e..772f64e 100644
--- a/TrackManager.cpp
+++ b/TrackManager.cpp
@@ -197,8 +197,8 @@ void TrackManager::setPROGSignal( bool on) {
 void TrackManager::setDCSignal(int16_t cab, byte speedbyte) {
   FOR_EACH_TRACK(t) {
     if (trackDCAddr[t]!=cab && cab != 0) continue;
-    if (track[t]->getMode()==TRACK_MODE_DC) track[t]->setDCSignal(speedbyte);
-    else if (track[t]->getMode()==TRACK_MODE_DCX) track[t]->setDCSignal(speedbyte ^ 128);
+    if (track[t]->getMode() & (TRACK_MODE_DC|TRACK_MODE_DCX))
+      track[t]->setDCSignal(speedbyte);
   }
 }    
 
@@ -223,11 +223,18 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
     pinpair p = track[trackToSet]->getSignalPin();
     //DIAG(F("Track=%c remove  pin %d"),trackToSet+'A', p.pin);
     gpio_reset_pin((gpio_num_t)p.pin);
-    pinMode(p.pin, OUTPUT); // gpio_reset_pin may reset to input
     if (p.invpin != UNUSED_PIN) {
       //DIAG(F("Track=%c remove ^pin %d"),trackToSet+'A', p.invpin);
       gpio_reset_pin((gpio_num_t)p.invpin);
-      pinMode(p.invpin, OUTPUT); // gpio_reset_pin may reset to input
+    }
+
+    if (mode == TRACK_MODE_EXT) {
+      pinMode(26, INPUT);
+      gpio_matrix_in(26, SIG_IN_FUNC228_IDX, false); //pads 224 to 228 available as loopback
+      gpio_matrix_out(p.pin, SIG_IN_FUNC228_IDX, false, false);
+      if (p.invpin != UNUSED_PIN) {
+	gpio_matrix_out(p.invpin, SIG_IN_FUNC228_IDX, true /*inverted*/, false);
+      }
     }
 #endif
 #ifndef DISABLE_PROG
@@ -261,10 +268,12 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
       track[trackToSet]->setBrake(false);
     }
 
+#ifndef ARDUINO_ARCH_ESP32
     // EXT is a special case where the signal pin is
     // turned off. So unless that is set, the signal
     // pin should be turned on
     track[trackToSet]->enableSignal(mode != TRACK_MODE_EXT);
+#endif
 
 #ifndef ARDUINO_ARCH_ESP32
     // re-evaluate HighAccuracy mode
@@ -320,8 +329,6 @@ bool TrackManager::setTrackMode(byte trackToSet, TRACK_MODE mode, int16_t dcAddr
 
 void TrackManager::applyDCSpeed(byte t) {
   uint8_t speedByte=DCC::getThrottleSpeedByte(trackDCAddr[t]);
-  if (track[t]->getMode()==TRACK_MODE_DCX)
-    speedByte = speedByte ^ 128; // reverse direction bit
   track[t]->setDCSignal(speedByte);
 }