diff --git a/config.h b/config.h
index f27a4b7..ae48023 100755
--- a/config.h
+++ b/config.h
@@ -35,10 +35,14 @@
 #define X_DIRECTION_BIT    5  // Uno Digital Pin 5
 #define Y_DIRECTION_BIT    6  // Uno Digital Pin 6
 #define Z_DIRECTION_BIT    7  // Uno Digital Pin 7
+#define STEP_MASK ((1<<X_STEP_BIT)|(1<<Y_STEP_BIT)|(1<<Z_STEP_BIT)) // All step bits
+#define DIRECTION_MASK ((1<<X_DIRECTION_BIT)|(1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT)) // All direction bits
+#define STEPPING_MASK (STEP_MASK | DIRECTION_MASK) // All stepping-related bits (step/direction)
 
 #define STEPPERS_DISABLE_DDR    DDRB
 #define STEPPERS_DISABLE_PORT   PORTB
 #define STEPPERS_DISABLE_BIT    0  // Uno Digital Pin 8
+#define STEPPERS_DISABLE_MASK (1<<STEPPERS_DISABLE_BIT)
 
 #define LIMIT_DDR       DDRB
 #define LIMIT_PIN       PINB
@@ -49,6 +53,7 @@
 #define LIMIT_INT       PCIE0  // Pin change interrupt enable pin
 #define LIMIT_INT_vect  PCINT0_vect 
 #define LIMIT_PCMSK     PCMSK0 // Pin change interrupt register
+#define LIMIT_MASK ((1<<X_LIMIT_BIT)|(1<<Y_LIMIT_BIT)|(1<<Z_LIMIT_BIT)) // All limit bits
 
 #define SPINDLE_ENABLE_DDR   DDRB
 #define SPINDLE_ENABLE_PORT  PORTB
@@ -60,15 +65,29 @@
 
 #define COOLANT_FLOOD_DDR   DDRC
 #define COOLANT_FLOOD_PORT  PORTC
-#define COOLANT_FLOOD_BIT   0  // Uno Analog Pin 0
+#define COOLANT_FLOOD_BIT   3  // Uno Analog Pin 3
 
 // #define ENABLE_M7  // Mist coolant disabled by default. Uncomment to enable.
+// NOTE: Uno analog pins 4 and 5 are reserved for an i2c interface, and may be installed at
+// a later date if flash and memory space allows.
 #ifdef ENABLE_M7
   #define COOLANT_MIST_DDR   DDRC
   #define COOLANT_MIST_PORT  PORTC
-  #define COOLANT_MIST_BIT   1 // Uno Analog Pin 1
+  #define COOLANT_MIST_BIT   4 // Uno Analog Pin 4
 #endif  
 
+#define PINOUT_DDR       DDRC
+#define PINOUT_PIN       PINC
+#define PINOUT_PORT      PORTC
+#define PIN_RESET        0  // Uno Analog Pin 0
+#define PIN_FEED_HOLD    1  // Uno Analog Pin 1
+#define PIN_CYCLE_START  2  // Uno Analog Pin 2
+#define PINOUT_INT       PCIE1  // Pin change interrupt enable pin
+#define PINOUT_INT_vect  PCINT1_vect
+#define PINOUT_PCMSK     PCMSK1 // Pin change interrupt register
+#define PINOUT_MASK ((1<<PIN_RESET)|(1<<PIN_FEED_HOLD)|(1<<PIN_CYCLE_START))
+
+
 // Default settings (used when resetting eeprom-settings)
 // TODO: Begin to fill these out for various as-built machines, i.e. config_sherline5400.h
 #define MICROSTEPS 4
diff --git a/limits.h b/limits.h
index 59f9008..a904ac9 100755
--- a/limits.h
+++ b/limits.h
@@ -21,7 +21,6 @@
 #ifndef limits_h
 #define limits_h 
 
-#define LIMIT_MASK ((1<<X_LIMIT_BIT)|(1<<Y_LIMIT_BIT)|(1<<Z_LIMIT_BIT)) // All limit bits
 #define MICROSECONDS_PER_ACCELERATION_TICK  (1000000/ACCELERATION_TICKS_PER_SECOND)
 
 // initialize the limits module
diff --git a/protocol.c b/protocol.c
index ee0926c..068c7a2 100755
--- a/protocol.c
+++ b/protocol.c
@@ -20,6 +20,7 @@
 */
 
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include "protocol.h"
 #include "gcode.h"
 #include "serial.h"
@@ -41,6 +42,11 @@ void protocol_init()
   char_counter = 0; // Reset line input
   iscomment = false;
   report_init_message(); // Welcome message   
+  
+  PINOUT_DDR &= ~(PINOUT_MASK); // Set as input pins
+  PINOUT_PORT |= PINOUT_MASK; // Enable internal pull-up resistors. Normal high operation.
+  PINOUT_PCMSK |= PINOUT_MASK;   // Enable specific pins of the Pin Change Interrupt
+  PCICR |= (1 << PINOUT_INT);   // Enable Pin Change Interrupt
 }
 
 // Executes user startup script, if stored.
@@ -59,6 +65,27 @@ void protocol_execute_startup()
   }  
 }
 
+// Pin change interrupt for pin-out commands, i.e. cycle start, feed hold, and reset. Sets
+// only the runtime command execute variable to have the main program execute these when 
+// its ready. This works exactly like the character-based runtime commands when picked off
+// directly from the incoming serial data stream.
+ISR(PINOUT_INT_vect) 
+{
+  // Enter only if any pinout pin is actively low.
+  if ((PINOUT_PIN & PINOUT_MASK) ^ PINOUT_MASK) { 
+    if (bit_isfalse(PINOUT_PIN,bit(PIN_RESET))) {
+      mc_alarm();
+      sys.execute |= EXEC_RESET; // Set as true
+    }
+    if (bit_isfalse(PINOUT_PIN,bit(PIN_FEED_HOLD))) {
+      sys.execute |= EXEC_FEED_HOLD; 
+    }
+    if (bit_isfalse(PINOUT_PIN,bit(PIN_CYCLE_START))) {
+      sys.execute |= EXEC_CYCLE_START;
+    }
+  }
+}
+
 // Executes run-time commands, when required. This is called from various check points in the main
 // program, primarily where there may be a while loop waiting for a buffer to clear space or any
 // point where the execution time from the last check point may be more than a fraction of a second.
diff --git a/report.c b/report.c
index 42456bf..d336677 100644
--- a/report.c
+++ b/report.c
@@ -65,7 +65,7 @@ void report_status_message(uint8_t status_code)
       case STATUS_HARD_LIMIT:
       printPgmString(PSTR("Limit triggered")); break;
       case STATUS_SETTING_DISABLED:
-      printPgmString(PSTR("Grbl setting disabled")); break;
+      printPgmString(PSTR("Setting disabled")); break;
       case STATUS_SETTING_VALUE_NEG:
       printPgmString(PSTR("Set value must be > 0.0")); break;
       case STATUS_SETTING_STEP_PULSE_MIN:
@@ -75,7 +75,7 @@ void report_status_message(uint8_t status_code)
       case STATUS_HOMING_ERROR:
       printPgmString(PSTR("Must be idle to home")); break;
       case STATUS_ABORT_CYCLE:
-      printPgmString(PSTR("Abort during cycle. Position may be lost")); break;
+      printPgmString(PSTR("Abort during cycle. Position maybe lost")); break;
       case STATUS_PURGE_CYCLE:
       printPgmString(PSTR("Can't purge buffer during cycle")); break;
     }
diff --git a/stepper.h b/stepper.h
index a72546f..84fe8c0 100755
--- a/stepper.h
+++ b/stepper.h
@@ -25,15 +25,9 @@
 #include <avr/io.h>
 
 // Some useful constants
-#define STEP_MASK ((1<<X_STEP_BIT)|(1<<Y_STEP_BIT)|(1<<Z_STEP_BIT)) // All step bits
-#define DIRECTION_MASK ((1<<X_DIRECTION_BIT)|(1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT)) // All direction bits
-#define STEPPING_MASK (STEP_MASK | DIRECTION_MASK) // All stepping-related bits (step/direction)
-#define STEPPERS_DISABLE_MASK (1<<STEPPERS_DISABLE_BIT)
-
 #define TICKS_PER_MICROSECOND (F_CPU/1000000)
 #define CYCLES_PER_ACCELERATION_TICK ((TICKS_PER_MICROSECOND*1000000)/ACCELERATION_TICKS_PER_SECOND)
 
-
 // Initialize and setup the stepper motor subsystem
 void st_init();