diff --git a/getopt.c b/getopt.c
new file mode 100755
index 0000000..1200447
--- /dev/null
+++ b/getopt.c
@@ -0,0 +1,138 @@
+/*
+Newsgroups: mod.std.unix
+Subject: public domain AT&T getopt source
+Date: 3 Nov 85 19:34:15 GMT
+
+Here's something you've all been waiting for:  the AT&T public domain
+source for getopt(3).  It is the code which was given out at the 1985
+UNIFORUM conference in Dallas.  I obtained it by electronic mail
+directly from AT&T.  The people there assure me that it is indeed
+in the public domain.
+
+25/1/2005 Henry Thomas <me(at)henri.net>
+
+Ported this original AT&T version of 'getopt' to windows.
+
+Added 'getargv' to parse the 'WinMain' 'lpCmdLine' argument and convert it
+into an argc/argv pair. This should improve portability between windows and
+unix/linux platforms.
+
+*/
+
+#include "321/getopt.h"
+#ifndef HAS_GETOPT_H
+
+#include <string.h>
+#if defined(_MSC_VER)
+#   include <io.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef HAS_WIN_GUI
+
+/* The windows gui version reports command line errors using MessageBox */
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#define ERR(s, c) if(opterr) {\
+    char buffer[64];\
+    _snprintf(buffer, 64, "%s%s%c", argv[0], s, c);\
+	MessageBox(NULL, buffer, "Command Line Error", MB_OK | MB_ICONERROR);\
+}
+
+#else
+
+#define ERR(s, c) if(opterr) {\
+    char errbuf[2];\
+	errbuf[0] = c; errbuf[1] = '\n';\
+	(void) write(2, argv[0], (unsigned)strlen(argv[0]));\
+	(void) write(2, s, (unsigned)strlen(s));\
+	(void) write(2, errbuf, 2);\
+}
+
+#endif
+
+int	opterr = 1;
+int	optind = 1;
+int	optopt;
+char *optarg;
+
+int getopt(int argc, char **argv, char *opts)
+{
+	static int sp = 1;
+	register int c;
+	register char *cp;
+
+    if(sp == 1) {
+        if(optind >= argc ||
+            argv[optind][0] != '-' || argv[optind][1] == '\0') {
+            return(-1);
+        }
+        else if(strcmp(argv[optind], "--") == 0) {
+            optind++;
+            return(-1);
+        }
+    }
+	optopt = c = argv[optind][sp];
+    if(c == ':' || (cp = strchr(opts, c)) == NULL) {
+        ERR(": illegal option -- ", c);
+        if(argv[optind][++sp] == '\0') {
+            optind++;
+            sp = 1;
+        }
+        return('?');
+    }
+    if(*++cp == ':') {
+        if(argv[optind][sp+1] != '\0') {
+            optarg = &argv[optind++][sp+1];
+        }
+        else if(++optind >= argc) {
+            ERR(": option requires an argument -- ", c);
+            sp = 1;
+            return('?');
+        }
+        else {
+            optarg = argv[optind++];
+        }
+        sp = 1;
+    }
+    else {
+        if(argv[optind][++sp] == '\0') {
+            sp = 1;
+            optind++;
+        }
+        optarg = NULL;
+    }
+	return(c);
+}
+
+#ifdef HAS_WIN_GUI
+
+char **getargv(char *cl, int *argc)
+{
+    static char *argv[MAX_ARGC];
+    int i;
+    for(i = 0; i < MAX_ARGC; i++) {
+        argv[i] = cl;
+LOOP:
+        cl++;
+        if(cl[0] == ' ') {
+            while(cl[1] == ' ') cl++;
+            *cl = 0;
+            cl++;
+        }
+        else {
+            if(cl[0]) {
+                goto LOOP;
+            }
+            i++;
+            break;
+        }
+    }
+    *argc = i;
+    return argv;
+}
+
+#endif
+#endif /* HAS_GETOPT_H */
diff --git a/getopt.h b/getopt.h
new file mode 100755
index 0000000..16803c9
--- /dev/null
+++ b/getopt.h
@@ -0,0 +1,93 @@
+/*
+Newsgroups: mod.std.unix
+Subject: public domain AT&T getopt source
+Date: 3 Nov 85 19:34:15 GMT
+
+Here's something you've all been waiting for:  the AT&T public domain
+source for getopt(3).  It is the code which was given out at the 1985
+UNIFORUM conference in Dallas.  I obtained it by electronic mail
+directly from AT&T.  The people there assure me that it is indeed
+in the public domain.
+
+25/1/2005 Henry Thomas <me(at)henri.net>
+
+Ported this original AT&T version of 'getopt' to windows.
+
+Added documentation to this header, so know what everything does.
+
+*/
+
+#ifndef GETOPT_H_
+#define GETOPT_H_
+
+#ifdef HAS_GETOPT_H
+#   include <getopt.h>
+#else
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern int opterr;
+
+/* If the value of the 'opterr' variable is nonzero, then getopt prints an
+error message to the standard error stream if it encounters an unknown option
+character or an option with a missing required argument. The windows version
+reports the error using a message box. This is the default behavior. If you
+set this variable to zero, getopt does not print any messages, but it still
+returns the character ? to indicate an error. */
+
+extern int optopt;
+
+/* When getopt encounters an unknown option character or an option with a
+missing required argument, it stores that option character the 'optopt'
+variable. You can use this for providing your own diagnostic messages. */
+
+extern int optind;
+
+/* The 'optind' variable is set by getopt to the index of the next element of
+the argv array to be processed. Once getopt has found all of the option
+arguments, you can use this variable to determine where the remaining
+non-option arguments begin. The initial value of this variable is 1. */
+
+extern char *optarg;
+
+/* The 'optarg' variable is set by getopt to point at the value of the
+option argument, for those options that accept arguments. */
+
+int getopt(int argc, char **argv, char *opts);
+
+/* The getopt function gets the next option argument from the argument list
+specified by the argv and argc arguments. Normally these values come directly
+from the arguments received by main.
+
+The options argument is a string that specifies the option characters that are
+valid for this program. An option character in this string can be followed
+by a colon (':') to indicate that it takes a required argument. */
+
+#ifdef WIN32
+
+#ifndef HAS_WIN_CLI
+#define HAS_WIN_GUI 1
+#endif
+
+/* Define 'HAS_WIN_CLI' if you plan to use this version of getopt in a
+windows console application */
+
+#define MAX_ARGC 32
+
+/* This is the maximum argument count that 'getargv' will return. */
+
+char **getargv(char *cl, int *argc);
+
+/* Parse a single command line sting and convert it into an argc/argv pair
+compatible with getopt */
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* HAS_GETOPT_H */
+#endif  /* GETOPT_H_ */
diff --git a/gpx.c b/gpx.c
index 2f30fe3..788cbbe 100644
--- a/gpx.c
+++ b/gpx.c
@@ -32,7 +32,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <strings.h>
+
+#ifdef _WIN32
+#include "getopt.h"
+#else
 #include <unistd.h>
+#endif
 
 #include "gpx.h"
 
@@ -47,6 +52,7 @@ static Machine replicator_1 = {
     {1170, 1100, 400, ENDSTOP_IS_MIN},        // z axis
     {1600, 96.275201870333662468889989185642, 3200, 1}, // a extruder
     {1600, 96.275201870333662468889989185642, 3200, 0}, // b extruder
+    1.75, // nominal filament diameter
     1,  // extruder count
     20, // timeout
 };
@@ -57,6 +63,7 @@ static Machine replicator_1D = {
     {1170, 1100, 400, ENDSTOP_IS_MIN},        // z axis
     {1600, 96.275201870333662468889989185642, 3200, 1}, // a extruder
     {1600, 96.275201870333662468889989185642, 3200, 0}, // b extruder
+    1.75, // nominal filament diameter
     2,  // extruder count
     20, // timeout
 };
@@ -67,6 +74,7 @@ static Machine replicator_2 = {
     {1170, 1100, 400, ENDSTOP_IS_MIN},        // z axis
     {1600, 96.275201870333662468889989185642, 3200, 0}, // a extruder
     {1600, 96.275201870333662468889989185642, 3200, 0}, // b extruder
+    1.75, // nominal filament diameter
     1,  // extruder count
     20, // timeout
 };
@@ -77,6 +85,7 @@ static Machine replicator_2X = {
     {1170, 1100, 400, ENDSTOP_IS_MIN},        // z axis
     {1600, 96.275201870333662468889989185642, 3200, 1}, // a extruder
     {1600, 96.275201870333662468889989185642, 3200, 0}, // b extruder
+    1.75, // nominal filament diameter
     2,  // extruder count
     20, // timeout
 };
@@ -89,6 +98,7 @@ Machine machine = {
     {1170, 400, ENDSTOP_IS_MIN},        // z axis
     {1600, 96.275201870333662468889989185642, 3200, 0}, // a extruder
     {1600, 96.275201870333662468889989185642, 3200, 0}, // b extruder
+    1.75, // nominal filament diameter
     1,  // extruder count
     20, // timeout
 };
@@ -100,9 +110,8 @@ static double get_home_feedrate(int flag);
 // GLOBAL VARIABLES
 
 Command command;            // the gcode command line
-Point5d currentPosition;    // the extruders current position in 5D space
-Point5d machineTarget;      // machine target point
-Point5d workTarget;         // work target point (including G10 offsets)
+Point5d currentPosition;    // the current position of the extruder in 5D space
+Point5d targetPosition;     // the target poaition the extruder will move to (including G10 offsets)
 Point2d excess;             // the accumulated rounding error in mm to step conversion
 int currentExtruder;        // the currently selectd extruder using Tn
 double currentFeedrate;     // the current feed rate
@@ -114,6 +123,7 @@ int positionKnown;          // is the current extruder position known
 int programState;           // gcode program state used to trigger start and end code sequences
 unsigned line_number;       // the current line number in the gcode file
 static char buffer[256];    // the statically allocated parse-in-place buffer
+double scale[2];            // A & B scaling for n x 0.01 mm change in nominal diameter
 
 FILE *in;                   // the gcode input file stream
 FILE *out;                  // the x3g output file stream
@@ -195,6 +205,9 @@ static void initialize_globals(void)
     programState = 0;
     
     line_number = 1;
+    
+    scale[0] = 0;
+    scale[1] = 0;
 }
 
 // STATE
@@ -388,7 +401,9 @@ double get_safe_feedrate(int flag, Ptr5d delta) {
     return feedrate;
 }
 
-// convert mm to steps using the current machine definition and accumulate the rounding error 
+// convert mm to steps using the current machine definition
+
+// IMPORTANT: this command changes the global excess value which accunulates the rounding remainder
 
 static Point5d mm_to_steps(Ptr5d mm, Ptr2d excess)
 {
@@ -398,12 +413,15 @@ static Point5d mm_to_steps(Ptr5d mm, Ptr2d excess)
     result.y = round(mm->y * machine.y.steps_per_mm);
     result.z = round(mm->z * machine.z.steps_per_mm);
     if(excess) {
+        // accumulate rounding remainder
         value = (mm->a * machine.a.steps_per_mm) + excess->a;
         result.a = round(value);
+        // changes to excess
         excess->a = value - result.a;
         
         value = (mm->b * machine.b.steps_per_mm) + excess->b;
         result.b = round(value);
+        // changes to excess
         excess->b = value - result.b;
     }
     else {
@@ -449,7 +467,6 @@ static void home_axes(unsigned direction)
         if(direction != machine.y.endstop) {
             fprintf(stderr, "(line %u) Semantic Warning: Y axis homing to %s endstop" EOL, line_number, direction ? "maximum" : "minimum");
         }
-        
     }
     if(xyz_flag & Z_IS_SET) {
         if(machine.z.home_feedrate < feedrate) {
@@ -522,6 +539,8 @@ static void wait_for_extruder(unsigned extruder_id, unsigned timeout)
  
 // 136 - extruder action command
 
+// Action 03 - Set toolhead target temperature
+
 static void set_extruder_temperature(unsigned extruder_id, unsigned temperature)
 {
     assert(extruder_id < machine.extruder_count);
@@ -540,6 +559,8 @@ static void set_extruder_temperature(unsigned extruder_id, unsigned temperature)
     if(write_16(temperature) == EOF) exit(1);
 }
 
+// Action 12 - Enable / Disable fan
+
 static void set_fan(unsigned extruder_id, unsigned state)
 {
     assert(extruder_id < machine.extruder_count);
@@ -558,6 +579,8 @@ static void set_fan(unsigned extruder_id, unsigned state)
     if(write_8(state) == EOF) exit(1);
 }
 
+// Action 13 - Enable / Disable extra output (blower fan)
+
 static void set_valve(unsigned extruder_id, unsigned state)
 {
     assert(extruder_id < machine.extruder_count);
@@ -576,6 +599,8 @@ static void set_valve(unsigned extruder_id, unsigned state)
     if(write_8(state) == EOF) exit(1);
 }
 
+// Action 31 - Set build platform target temperature
+
 static void set_build_platform_temperature(unsigned extruder_id, unsigned temperature)
 {
     assert(extruder_id < machine.extruder_count);
@@ -594,7 +619,7 @@ static void set_build_platform_temperature(unsigned extruder_id, unsigned temper
     if(write_16(temperature) == EOF) exit(1);
 }
 
-// 137 - Enable/disable axes steppers
+// 137 - Enable / Disable axes steppers
 
 static void set_steppers(unsigned axes, unsigned state)
 {
@@ -613,7 +638,7 @@ static void set_steppers(unsigned axes, unsigned state)
 static void queue_absolute_point()
 {
     long longestDDA = get_longest_dda();
-    Point5d steps = mm_to_steps(&workTarget, &excess);
+    Point5d steps = mm_to_steps(&targetPosition, &excess);
     
     if(write_8(139) == EOF) exit(1);
     
@@ -634,16 +659,13 @@ static void queue_absolute_point()
     
     // uint32: Feedrate, in microseconds between steps on the max delta. (DDA)
     if(write_32((int)longestDDA) == EOF) exit(1);
-    
-    currentPosition = machineTarget;
-    positionKnown = 1;
 }
 
 // 140 - Set extended position
 
 static void set_position()
 {
-    Point5d steps = mm_to_steps(&workTarget, &excess);
+    Point5d steps = mm_to_steps(&currentPosition, NULL);
     if(write_8(140) == EOF) exit(1);
     
     // int32: X position, in steps
@@ -719,9 +741,43 @@ static void set_pot_value(unsigned axis, unsigned value)
 }
  
 // 146 - Set RGB LED value
+
+static void set_LED(unsigned red, unsigned green, unsigned blue, unsigned blink)
+{
+    if(write_8(146) == EOF) exit(1);
+    
+    // uint8: red value (all pix are 0-255)
+    if(write_8(red) == EOF) exit(1);
+    
+    // uint8: green
+    if(write_8(green) == EOF) exit(1);
+    
+    // uint8: blue
+    if(write_8(blue) == EOF) exit(1);
+    
+    // uint8: blink rate (0-255 valid)
+    if(write_8(blink) == EOF) exit(1);
+    
+    // uint8: 0 (reserved for future use)
+    if(write_8(0) == EOF) exit(1);
+}
  
 // 147 - Set Beep
- 
+
+static void set_beep(unsigned frequency, unsigned milliseconds)
+{
+    if(write_8(147) == EOF) exit(1);
+    
+    // uint16: frequency
+    if(write_16(frequency) == EOF) exit(1);
+
+    // uint16: buzz length in ms
+    if(write_16(milliseconds) == EOF) exit(1);
+
+    // uint8: 0 (reserved for future use)
+    if(write_8(0) == EOF) exit(1);
+}
+
 // 148 - Pause for button
 
 // 149 - Display message to LCD
@@ -836,10 +892,13 @@ static void end_build()
  
 // 155 - Queue extended point x3g
 
+// IMPORTANT: this command updates the parser state
+
 static void queue_point(double feedrate)
 {
     Point5d deltaMM;
     Point5d deltaSteps;
+    Point5d target = targetPosition;
 
     // Because we don't know our previous position, we can't calculate the feedrate or
     // distance correctly, so we use an unaccelerated command with a fixed DDA
@@ -850,7 +909,7 @@ static void queue_point(double feedrate)
     
     // compute the relative distance traveled along each axis and convert to steps
     if(command.flag & X_IS_SET) {
-        deltaMM.x = machineTarget.x - currentPosition.x;
+        deltaMM.x = targetPosition.x - currentPosition.x;
         deltaSteps.x = round(fabs(deltaMM.x) * machine.x.steps_per_mm);
     }
     else {
@@ -859,7 +918,7 @@ static void queue_point(double feedrate)
     }
     
     if(command.flag & Y_IS_SET) {
-        deltaMM.y = machineTarget.y - currentPosition.y;
+        deltaMM.y = targetPosition.y - currentPosition.y;
         deltaSteps.y = round(fabs(deltaMM.y) * machine.y.steps_per_mm);
     }
     else {
@@ -868,7 +927,7 @@ static void queue_point(double feedrate)
     }
     
     if(command.flag & Z_IS_SET) {
-        deltaMM.z = machineTarget.z - currentPosition.z;
+        deltaMM.z = targetPosition.z - currentPosition.z;
         deltaSteps.z = round(fabs(deltaMM.z) * machine.z.steps_per_mm);
     }
     else {
@@ -877,7 +936,7 @@ static void queue_point(double feedrate)
     }
     
     if(command.flag & A_IS_SET) {
-        deltaMM.a = workTarget.a - currentPosition.a;
+        deltaMM.a = targetPosition.a - currentPosition.a;
         deltaSteps.a = round(fabs(deltaMM.a) * machine.a.steps_per_mm);
     }
     else {
@@ -886,7 +945,7 @@ static void queue_point(double feedrate)
     }
     
     if(command.flag & B_IS_SET) {
-        deltaMM.b = workTarget.b - currentPosition.b;
+        deltaMM.b = targetPosition.b - currentPosition.b;
         deltaSteps.b = round(fabs(deltaMM.b) * machine.b.steps_per_mm);
     }
     else {
@@ -898,8 +957,8 @@ static void queue_point(double feedrate)
     if(magnitude(command.flag, &deltaSteps) > 0) {
         double distance = magnitude(command.flag & XYZ_BIT_MASK, &deltaMM);
         
-        workTarget.a = -deltaMM.a;
-        workTarget.b = -deltaMM.b;
+        target.a = -deltaMM.a;
+        target.b = -deltaMM.b;
         
         deltaMM.x = fabs(deltaMM.x);
         deltaMM.y = fabs(deltaMM.y);
@@ -933,8 +992,8 @@ static void queue_point(double feedrate)
                 double mmPerRevolution = machine.a.motor_steps * (1 / machine.a.steps_per_mm);
                 // set distance
                 deltaMM.a = numRevolutions * mmPerRevolution;
-                deltaSteps.a = round(fabs(workTarget.a - currentPosition.a) * machine.a.steps_per_mm);
-                workTarget.a = -deltaMM.a;
+                deltaSteps.a = round(fabs(targetPosition.a - currentPosition.a) * machine.a.steps_per_mm);
+                target.a = -deltaMM.a;
             }
         }
         if(deltaMM.b == 0.0) {
@@ -945,12 +1004,12 @@ static void queue_point(double feedrate)
                 double mmPerRevolution = machine.b.motor_steps * (1 / machine.b.steps_per_mm);
                 // set distance
                 deltaMM.b = numRevolutions * mmPerRevolution;
-                deltaSteps.b = round(fabs(workTarget.b - currentPosition.b) * machine.b.steps_per_mm);
-                workTarget.b = -deltaMM.b;
+                deltaSteps.b = round(fabs(targetPosition.b - currentPosition.b) * machine.b.steps_per_mm);
+                target.b = -deltaMM.b;
             }
         }
 
-        Point5d steps = mm_to_steps(&workTarget, &excess);
+        Point5d steps = mm_to_steps(&target, &excess);
         
         double usec = (60 * 1000 * 1000 * minutes);
         
@@ -987,8 +1046,6 @@ static void queue_point(double feedrate)
         
         // uint16: feedrate in mm/s, multiplied by 64 to assist fixed point calculation on the bot
         if(write_16((unsigned)(feedrate * 64.0)) == EOF) exit(1);
-        
-        currentPosition = machineTarget;
 	}
 }
 
@@ -1358,30 +1415,30 @@ int main(int argc, char * argv[])
             }
         }
         
-        // CALCULATE TARGET POINT
+        // CALCULATE TARGET POSITION
         
         // x
         if(command.flag & X_IS_SET) {
-            machineTarget.x = isRelative ? (currentPosition.x + command.x) : command.x;
+            targetPosition.x = isRelative ? (currentPosition.x + command.x) : command.x;
         }
         else {
-            machineTarget.x = currentPosition.x;
+            targetPosition.x = currentPosition.x;
         }
         
         // y
         if(command.flag & Y_IS_SET) {
-            machineTarget.y = isRelative ? (currentPosition.y + command.y) : command.y;
+            targetPosition.y = isRelative ? (currentPosition.y + command.y) : command.y;
         }
         else {
-            machineTarget.y = currentPosition.y;
+            targetPosition.y = currentPosition.y;
         }
         
         // z
         if(command.flag & Z_IS_SET) {
-            machineTarget.z = isRelative ? (currentPosition.z + command.z) : command.z;
+            targetPosition.z = isRelative ? (currentPosition.z + command.z) : command.z;
         }
         else {
-            machineTarget.z = currentPosition.z;
+            targetPosition.z = currentPosition.z;
         }
         
         // we treat e as short hand for a or b being set
@@ -1389,29 +1446,29 @@ int main(int argc, char * argv[])
         if(command.flag & E_IS_SET) {
             if(currentExtruder == 0) {
                 // a = e
-                machineTarget.a = isRelative ? (currentPosition.a + command.e) : command.e;
+                targetPosition.a = isRelative ? (currentPosition.a + command.e) : command.e;
                 command.flag |= A_IS_SET;
                 command.a = command.e;
                 
                 // b
                 if(command.flag & B_IS_SET) {
-                    machineTarget.b = isRelative ? (currentPosition.b + command.b) : command.b;
+                    targetPosition.b = isRelative ? (currentPosition.b + command.b) : command.b;
                 }
                 else {
-                    machineTarget.b = currentPosition.b;
+                    targetPosition.b = currentPosition.b;
                 }
             }
             else {                
                 // a
                 if(command.flag & A_IS_SET) {
-                    machineTarget.a = isRelative ? (currentPosition.a + command.a) : command.a;
+                    targetPosition.a = isRelative ? (currentPosition.a + command.a) : command.a;
                 }
                 else {
-                    machineTarget.a = currentPosition.a;
+                    targetPosition.a = currentPosition.a;
                 }
                 
                 // b = e
-                machineTarget.b = isRelative ? (currentPosition.b + command.e) : command.e;
+                targetPosition.b = isRelative ? (currentPosition.b + command.e) : command.e;
                 command.flag |= B_IS_SET;
                 command.b = command.e;
             }
@@ -1419,17 +1476,17 @@ int main(int argc, char * argv[])
         else {        
             // a
             if(command.flag & A_IS_SET) {
-                machineTarget.a = isRelative ? (currentPosition.a + command.a) : command.a;
+                targetPosition.a = isRelative ? (currentPosition.a + command.a) : command.a;
             }
             else {
-                machineTarget.a = currentPosition.a;
+                targetPosition.a = currentPosition.a;
             }
             // b
             if(command.flag & B_IS_SET) {
-                machineTarget.b = isRelative ? (currentPosition.b + command.b) : command.b;
+                targetPosition.b = isRelative ? (currentPosition.b + command.b) : command.b;
             }
             else {
-                machineTarget.b = currentPosition.b;
+                targetPosition.b = currentPosition.b;
             }
         }
         
@@ -1438,13 +1495,11 @@ int main(int argc, char * argv[])
             currentFeedrate = command.f;
         }
         
-        // CALCULATE WORK OFFSET
+        // CALCULATE OFFSET
         
-        workTarget.x = machineTarget.x + offset[currentOffset].x;
-        workTarget.y = machineTarget.y + offset[currentOffset].y;
-        workTarget.z = machineTarget.z + offset[currentOffset].z;
-        workTarget.a = machineTarget.a;
-        workTarget.b = machineTarget.b;
+        if(command.flag & X_IS_SET) targetPosition.x += offset[currentOffset].x;
+        if(command.flag & Y_IS_SET) targetPosition.y += offset[currentOffset].y;
+        if(command.flag & Z_IS_SET) targetPosition.z += offset[currentOffset].z;
 
         // INTERPRET COMMAND
         
@@ -1455,12 +1510,14 @@ int main(int argc, char * argv[])
                 case 0:
                     if(command.flag & F_IS_SET) {
                         queue_point(currentFeedrate);
+                        currentPosition = targetPosition;
+                        positionKnown = 1;
                     }
                     else {
                         Point3d delta;
-                        if(command.flag & X_IS_SET) delta.x = fabs(workTarget.x - currentPosition.x);
-                        if(command.flag & Y_IS_SET) delta.y = fabs(workTarget.y - currentPosition.y);
-                        if(command.flag & Z_IS_SET) delta.z = fabs(workTarget.z - currentPosition.z);
+                        if(command.flag & X_IS_SET) delta.x = fabs(targetPosition.x - currentPosition.x);
+                        if(command.flag & Y_IS_SET) delta.y = fabs(targetPosition.y - currentPosition.y);
+                        if(command.flag & Z_IS_SET) delta.z = fabs(targetPosition.z - currentPosition.z);
                         double length = magnitude(command.flag & XYZ_BIT_MASK, (Ptr5d)&delta);
                         double candidate, feedrate = DBL_MAX;
                         if(command.flag & X_IS_SET && delta.x != 0.0) {
@@ -1482,12 +1539,16 @@ int main(int argc, char * argv[])
                             feedrate = machine.x.max_feedrate;
                         }
                         queue_point(feedrate);
+                        currentPosition = targetPosition;
+                        positionKnown = 1;
                     }
                     break;
                     
                     // G1 - Coordinated Motion
                 case 1:
                     queue_point(currentFeedrate);
+                    currentPosition = targetPosition;
+                    positionKnown = 1;
                     break;
                     
                     // G2 - Clockwise Arc
@@ -1508,15 +1569,21 @@ int main(int argc, char * argv[])
                 case 10:
                     if(command.flag & P_IS_SET && command.p >= 1.0 && command.p <= 6.0) {
                         i = (int)command.p;
-                        if(command.flag & X_IS_SET) offset[i].x = machineTarget.x;
-                        if(command.flag & Y_IS_SET) offset[i].y = machineTarget.y;
-                        if(command.flag & Z_IS_SET) offset[i].z = machineTarget.z;
+                        if(command.flag & X_IS_SET) offset[i].x = command.x;
+                        if(command.flag & Y_IS_SET) offset[i].y = command.y;
+                        if(command.flag & Z_IS_SET) offset[i].z = command.z;
                     }
                     else {
                         fprintf(stderr, "(line %u) Syntax Error: G10 is missing coordiante system, use Pn where n is 1-6" EOL, line_number);
                         exit(1);
                     }
                     break;
+                
+                    // G21 - Use Milimeters as Units (IGNORED)
+                    // G71 - Use Milimeters as Units (IGNORED)
+                case 21:
+                case 71:
+                    break;
                     
                     // G53 - Set absolute coordinate system
                 case 53:
@@ -1570,14 +1637,18 @@ int main(int argc, char * argv[])
                     break;
 
                     // G92 - Define current position on axes
-                case 92:
+                case 92: {
+                    if(command.flag & X_IS_SET) currentPosition.x = command.x;
+                    if(command.flag & Y_IS_SET) currentPosition.y = command.y;
+                    if(command.flag & Z_IS_SET) currentPosition.z = command.z;
+                    if(command.flag & A_IS_SET) currentPosition.a = command.a;
+                    if(command.flag & B_IS_SET) currentPosition.b = command.b;
+                    // check if we know where we are
+                    int mask = machine.extruder_count == 1 ? (XYZ_BIT_MASK | A_IS_SET) : AXES_BIT_MASK;
+                    if((command.flag & mask) == mask) positionKnown = 1;
                     set_position();
-                    if(command.flag & X_IS_SET) currentPosition.x = machineTarget.x;
-                    if(command.flag & Y_IS_SET) currentPosition.y = machineTarget.y;
-                    if(command.flag & Z_IS_SET) currentPosition.z = machineTarget.z;
-                    if(command.flag & A_IS_SET) currentPosition.a = machineTarget.a;
-                    if(command.flag & B_IS_SET) currentPosition.b = machineTarget.b;
                     break;
+                }
                     
                     // G130 - Set given axes potentiometer Value
                 case 130:
@@ -1630,6 +1701,10 @@ int main(int argc, char * argv[])
                     }
                     if(extruder_id < machine.extruder_count) {
                         if(currentExtruder != extruder_id) {
+                            // check for active G10 offset
+                            if(currentOffset == currentExtruder + 1) {
+                                currentOffset = extruder_id + 1;
+                            }
                             currentExtruder = extruder_id;
                             change_extruder(extruder_id);
                         }
@@ -1670,18 +1745,18 @@ int main(int argc, char * argv[])
                 case 71:
                     if(command.flag & COMMENT_IS_SET) {
                         if(command.flag & P_IS_SET) {
-                            display_message(command.comment, command.p, 0);
+                            display_message(command.comment, command.p, 1);
                         }
                         else {
-                            display_message(command.comment, 0, 0);
+                            display_message(command.comment, 0, 1);
                         }
                     }
                     else {
                         if(command.flag & P_IS_SET) {
-                            display_message("Press M to continue", command.p, 0);
+                            display_message("Press M to continue", command.p, 1);
                         }
                         else {
-                            display_message("Press M to continue", 0, 0);
+                            display_message("Press M to continue", 0, 1);
                         }
                     }
                     break;
@@ -1732,6 +1807,9 @@ int main(int argc, char * argv[])
                         unsigned extruder_id = (unsigned)command.t;
                         if(extruder_id < machine.extruder_count) {
                             set_steppers(extruder_id == 0 ? A_IS_SET : B_IS_SET, 1);
+                            tool[extruder_id].motor_enabled = 1;
+                            // update the direction
+                            tool[extruder_id].rpm = command.m == 101 ? fabs(tool[extruder_id].rpm) : -fabs(tool[extruder_id].rpm);
                         }
                         else {
                             fprintf(stderr, "(line %u) Semantic Warning: M%u cannot select non-existant extruder T%u" EOL, line_number, command.m, extruder_id);
@@ -1740,6 +1818,9 @@ int main(int argc, char * argv[])
                     }
                     else {
                         set_steppers(currentExtruder == 0 ? A_IS_SET : B_IS_SET, 1);
+                        tool[currentExtruder].motor_enabled = 1;
+                        // update the direction
+                        tool[currentExtruder].rpm = command.m == 101 ? fabs(tool[currentExtruder].rpm) : -fabs(tool[currentExtruder].rpm);
                     }
                     break;
                     
@@ -1749,6 +1830,7 @@ int main(int argc, char * argv[])
                         unsigned extruder_id = (unsigned)command.t;
                         if(extruder_id < machine.extruder_count) {
                             set_steppers(extruder_id == 0 ? A_IS_SET : B_IS_SET, 0);
+                            tool[extruder_id].motor_enabled = 0;
                         }
                         else {
                             fprintf(stderr, "(line %u) Semantic Warning: M103 cannot select non-existant extruder T%u" EOL, line_number, extruder_id);
@@ -1757,6 +1839,7 @@ int main(int argc, char * argv[])
                     }
                     else {
                         set_steppers(currentExtruder == 0 ? A_IS_SET : B_IS_SET, 0);
+                        tool[currentExtruder].motor_enabled = 0;
                     }
                     break;
                     
@@ -1818,6 +1901,28 @@ int main(int argc, char * argv[])
                     }
                     break;
                     
+                    // M108 - set extruder motor 5D 'simulated' RPM
+                case 108:
+                    if(command.flag & R_IS_SET) {
+                        if(command.flag & T_IS_SET) {
+                            unsigned extruder_id = (unsigned)command.t;
+                            if(extruder_id < machine.extruder_count) {
+                                tool[extruder_id].rpm = command.r;
+                            }
+                            else {
+                                fprintf(stderr, "(line %u) Semantic Warning: M108 cannot select non-existant extruder T%u" EOL, line_number, extruder_id);
+                            }
+                        }
+                        else {
+                            tool[currentExtruder].rpm = command.r;
+                        }
+                    }
+                    else {
+                        fprintf(stderr, "(line %u) Syntax Error: M108 is missing motor RPM, use Rn where n is 0-5" EOL, line_number);
+                        exit(1);
+                    }
+                    break;
+                    
                     // M109 - Set Build Platform Temperature
                     // M140 - Set Build Platform Temperature (skeinforge)
                 case 109:
@@ -1879,22 +1984,6 @@ int main(int argc, char * argv[])
                         set_valve(currentExtruder, 0);
                     }
                     break;
-
-                    // M137 - Enable axes steppers
-                case 137:
-                    break;
-                    
-                    // M138 - Disable axes steppers
-                case 138:
-                    break;
-
-                    // M146 - Set RGB LED value
-                case 146:
-                    break;
-                    
-                    // M147 - Set Beep
-                case 147:
-                    break;
                     
                     // M131 - Store Current Position to EEPROM
                 case 131:
@@ -1921,6 +2010,56 @@ int main(int argc, char * argv[])
                     }
                     break;
                     
+                    // M137 - Enable axes steppers
+                case 137:
+                    if(command.flag & AXES_BIT_MASK) {
+                        set_steppers(command.flag & AXES_BIT_MASK, 1);
+                        if(command.flag & A_IS_SET) tool[0].motor_enabled = 1;
+                        if(command.flag & B_IS_SET) tool[1].motor_enabled = 1;
+                    }
+                    else {
+                        fprintf(stderr, "(line %u) Syntax Error: M137 is missing axes, use X Y Z A B" EOL, line_number);
+                        exit(1);
+                    }
+                    break;
+                    
+                    // M138 - Disable axes steppers
+                case 138:
+                    if(command.flag & AXES_BIT_MASK) {
+                        set_steppers(command.flag & AXES_BIT_MASK, 0);
+                        if(command.flag & A_IS_SET) tool[0].motor_enabled = 0;
+                        if(command.flag & B_IS_SET) tool[1].motor_enabled = 0;
+                    }
+                    else {
+                        fprintf(stderr, "(line %u) Syntax Error: M138 is missing axes, use X Y Z A B" EOL, line_number);
+                        exit(1);
+                    }
+                    break;
+                    
+                    // M146 - Set RGB LED value (RLS - P)
+                case 146: {
+                    unsigned red = 0;
+                    if(command.flag & R_IS_SET) red = (unsigned)command.r & 0xFF;
+                    unsigned green = 0;
+                    if(command.flag & L_IS_SET) green = (unsigned)command.l & 0xFF;
+                    unsigned blue = 0;
+                    if(command.flag & S_IS_SET) blue = (unsigned)command.s & 0xFF;
+                    unsigned blink = 0;
+                    if(command.flag & P_IS_SET) blink = (unsigned)command.p & 0xFF;
+                    set_LED(red, green, blue, blink);
+                    break;
+                }
+
+                    // M147 - Set Beep (SP)
+                case 147: {
+                    unsigned frequency = 6000;
+                    if(command.flag & S_IS_SET) frequency = (unsigned)command.s & 0xFFFF;
+                    unsigned milliseconds = 100;
+                    if(command.flag & P_IS_SET) milliseconds = (unsigned)command.p & 0xFFFF;
+                    set_beep(frequency, milliseconds);
+                    break;
+                }
+
                     // M320 - Acceleration on for subsequent instructions
                 case 320:
                     set_acceleration(1);
@@ -1934,23 +2073,31 @@ int main(int argc, char * argv[])
                     fprintf(stderr, "(line %u) Syntax Warning: unsupported mcode command 'M%u'" EOL, line_number, command.m);
             }
         }
-        else if(command.flag & T_IS_SET) {
-            unsigned extruder_id = (unsigned)command.t;
-            if(extruder_id < machine.extruder_count) {
-                if(currentExtruder != extruder_id) {
-                    currentExtruder = extruder_id;
-                    change_extruder(extruder_id);
-                    command_line++;
+        else {
+            if(command.flag & T_IS_SET) {
+                unsigned extruder_id = (unsigned)command.t;
+                if(extruder_id < machine.extruder_count) {
+                    if(currentExtruder != extruder_id) {
+                        command_line++;
+                        // check for active G10 offset
+                        if(currentOffset == currentExtruder + 1) {
+                            currentOffset = extruder_id + 1;
+                        }
+                        currentExtruder = extruder_id;
+                        change_extruder(extruder_id);
+                    }
+                }
+                else {
+                    fprintf(stderr, "(line %u) Semantic Warning: T%u cannot select non-existant extruder" EOL, line_number, extruder_id);
                 }
             }
-            else {
-                fprintf(stderr, "(line %u) Semantic Warning: T%u cannot select non-existant extruder" EOL, line_number, extruder_id);
+            if(command.flag & AXES_BIT_MASK) {
+                command_line++;
+                queue_point(currentFeedrate);
+                currentPosition = targetPosition;
+                positionKnown = 1;
             }
         }
-        else if(command.flag & AXES_BIT_MASK) {
-            command_line++;
-            queue_point(currentFeedrate);
-        }
         // update progress
         if(filesize && build_percent && command_line) {
             unsigned percent = (unsigned)round(100.0 * (double)ftell(in) / (double)filesize);
diff --git a/gpx.h b/gpx.h
index 43a5904..748a8d0 100644
--- a/gpx.h
+++ b/gpx.h
@@ -142,6 +142,7 @@ typedef struct tMachine {
     Axis z;
     Extruder a;
     Extruder b;
+    double filament_diameter;
     unsigned extruder_count;
     unsigned timeout;
 } Machine;
diff --git a/lint.gcode b/lint.gcode
index 52f597e..f5525ca 100644
--- a/lint.gcode
+++ b/lint.gcode
@@ -19,6 +19,7 @@
 ;  You should have received a copy of the GNU General Public License
 ;  along with this program; if not, write to the Free Software Foundation,
 ;  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
 ; PREFIX
 
 M70 (M103 - extruder off)
@@ -58,16 +59,11 @@ G10 P4 X40 Y40 Z40
 G10 P5 X50 Y50 Z50
 G10 P6 X60 Y60 Z60
 
-; G20 - Use Inches as Units
-; G70 - Use Inches as Units
-;M70 (G20 - imperial units)
-;G20
-;G1 X1 Y1 Z1 E0.197
-
 ; G21 - Use Milimeters as Units
 ; G71 - Use Milimeters as Units
-;M70 (G21 - metric units)
-;G21
+M70 (G21 - metric units)
+G21
+G71
 
 ; G28 - Home given axes to maximum
 M70 (G28 - home to max)
@@ -147,18 +143,6 @@ M70 (M104 - set temp)
 M104 S230 T0
 M104 S230 T1
 
-; M3 - Spindle On - Clockwise
-;M70 (M3 - spindle on)
-;M3
-
-; M4 - Spindle On - Counter Clockwise
-;M70 (M4 - spindle on)
-;M4
-
-; M5 - Spindle Off
-;M70 (M5 - spindle off)
-;M5
-
 ; M6 - Wait for toolhead to come up to reach (or exceed) temperature
 M70 (M6 - wait for tool)
 M6 T0
@@ -188,32 +172,6 @@ M6
 M70 (T1 - tool change)
 T1
 
-; M13 - Spindle CW and Coolant A On
-;M70 (M13 - spindle +cool)
-;M13
-
-; M14 - Spindle CCW and Coolant A On
-;M70 (M14 - spindle +cool)
-;M14
-
-; M17 - Enable Motor(s)
-;M70 (M17 - enable motor)
-;M17
-
-; M18 - Disable Motor(s)
-;M70 (M18 - disable motor)
-;M18
-
-; M21 - Open Collet
-;M70 (M21 - open collet)
-;M21
-
-; M22 - Close Collet
-;M70 (M22 - close collet)
-;M22
-
-; M30 - Program Rewind
-
 ; M70 - Display Message On Machine
 M70 P20 (This is a really large message that will take up quite a few rows to display on the makerbot LCD screen)
 
@@ -232,34 +190,85 @@ M70 (M73 - progress)
 M73 P10 (build progress)
 
 ; M101 - Turn Extruder On, Forward
+M70 (M101 - extruder on-f)
+M101 T1
+M101 T0
+
 ; M102 - Turn Extruder On, Reverse
+M70 (M102 - extruder on-r)
+M102 T1
+M102 T0
+
 ; M103 - Turn Extruder Off
+M70 (M103 - extruder off)
+M103 T1
+M103 T0
+
 ; M104 - Set Temperature
-; M105 - Get Temperature
-; M106 - Turn Automated Build Platform (or the Fan, on older models) On
-; M107 - Turn Automated Build Platform (or the Fan, on older models) Off
-; M108 - Set Extruder's Max Speed (R = RPM, P = PWM)
+M70 (M104 - set temp)
+M104 T1 S240
+M104 T0 S230
+
+; M108 - Set Extruder's Max Speed (R = RPM)
+M70 (M108 - set rpm)
+M108 T1 R5.0
+M108 T0 R3.0
+
 ; M109 - Set Build Platform Temperature
-; M110 - Set Build Chamber Temperature
+M70 (M109 - hbp temp)
+M109 S110
+
 ; M126 - Valve Open
+M70 (M126 - blower on)
+M126
+
 ; M127 - Valve Close
-; M128 - "Get Position
+M70 (M127 - blower off)
+M127
+
 ; M131 - Store Current Position to EEPROM
+M70 (M131 - store EEPROM)
+M131 X Y Z A B
+
 ; M132 - Load Current Position from EEPROM
+M70 (M132 - load EEPROM)
+M132 X Y Z A B
+
+; M137 - Enable axes steppers
+M70 (M137 - steppers on)
+M132 X Y Z A B
+
+; M138 - Disable axes steppers
+M70 (M138 - steppers on)
+M138 X Y Z A B
+
+; M146 - Set RGB LED value
+M70 (M146 - set LED)
+M146 R255 L0 S0 P0
+
+; M147 - Set Beep
+M70 (M147 - set beep)
+M147 S4000 P100
+
 ; M140 - Set Build Platform Temperature
-; M141 - Set Chamber Temperature (Ignored)
-; M142 - Set Chamber Holding Pressure (Ignored)
-; M200 - Reset driver
-; M300 - Set Servo 1 Position
-; M301 - Set Servo 2 Position
-; M310 - Start data capture
-; M311 - Stop data capture
-; M312 - Log a note to the data capture store
+M70 (M140 - hbp temp)
+M140 T0 S100
+
 ; M320 - Acceleration on for subsequent instructions
+M70 (M320 - acc on)
+M320
+
 ; M321 - Acceleration off for subsequent instructions
+M70 (M21 - acc off)
+M321
+
+; T1 - Set Current Tool 1
+M70 (T1 - set tool)
+T1
 
 ; T0 - Set Current Tool 0
-; T1 - Set Current Tool 1
+M70 (T0 - set tool)
+T0
 
 ;POSTFIX
 M70 (M73 - end build)
diff --git a/s3g-decompiler.py b/s3g-decompiler.py
new file mode 100644
index 0000000..598d4c2
--- /dev/null
+++ b/s3g-decompiler.py
@@ -0,0 +1,179 @@
+#!/usr/bin/python
+#
+#  s3g-decompiler.py
+#
+#  Created by Adam Mayer on Jan 25 2011.
+#
+#  Originally from ReplicatorG sources /src/replicatorg/scripts
+#  which are part of the ReplicatorG project - http://www.replicat.org
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+import struct
+import sys
+
+toolCommandTable = {
+    1: ("", "[1] init: Initialize firmware to boot state"),
+    3: ("<H", "[3] Extruder: set temperature = %i"),
+    4: ("<B", "[4] Motor 1: set speed (PWM) = %i"),
+    5: ("<B", "[5] Motor 2: set speed (PWM) = %i"),
+    6: ("<I", "[6] Motor 1: set speed (RPM) = %i"),
+    7: ("<I", "[7] Motor 2: set speed (RPM) = %i"),
+    8: ("<I", "[8] Motor 1: set direction = %i"),
+    9: ("<I", "[9] Motor 2: set direction = %i"),
+    10: ("B", "[10] Motor 1: toggle = %d"),
+    11: ("B", "[11] Motor 2: toggle = %d"),
+    12: ("B", "[12] Fan: toggle = %d"),
+    13: ("B", "[13] Valve: toggle = %d"),
+    13: ("B", "[14] Servo 1: angle = %d"),
+    13: ("B", "[15] Serve 2: angle = %d"),
+    27: ("B", "[27] Automated build platform: toggle = %d"),
+    31: ("<H", "[31] Build Platform: set temperature = %i"),
+}
+
+def parseToolAction():
+    global s3gFile
+    packetStr = s3gFile.read(3)
+    if len(packetStr) != 3:
+        raise "Incomplete s3g file during tool command parse"
+    (index,command,payload) = struct.unpack("<BBB",packetStr)
+    contents = s3gFile.read(payload)
+    if len(contents) != payload:
+        raise "Incomplete s3g file: tool packet truncated"
+    return (index,command,contents)
+
+def printToolAction(tuple):
+    print "\t[136] Tool %i:" % (tuple[0]),
+    # command - tuple[1]
+    # data - tuple[2]
+    (parse, disp) = toolCommandTable[tuple[1]]
+    if type(parse) == type(""):
+        packetLen = struct.calcsize(parse)
+        if len(tuple[2]) != packetLen:
+            raise "Packet incomplete"
+        parsed = struct.unpack(parse,tuple[2])
+    else:
+        parsed = parse()
+    if type(disp) == type(""):
+        print disp % parsed
+
+def parseDisplayMessageAction():
+    global s3gFile
+    packetStr = s3gFile.read(4)
+    if len(packetStr) < 4:
+        raise "Incomplete s3g file during tool command parse"
+    (options,offsetX,offsetY,timeout) = struct.unpack("<BBBB",packetStr)
+    message = "";
+    while True:
+       c = s3gFile.read(1);
+       if c == '\0':
+          break;
+       else:
+          message += c;
+
+    return (options,offsetX,offsetY,timeout,message)
+
+def parseBuildStartNotificationAction():
+    global s3gFile
+    packetStr = s3gFile.read(4)
+    if len(packetStr) < 4:
+        raise "Incomplete s3g file during tool command parse"
+    (steps) = struct.unpack("<i",packetStr)
+    buildName = "";
+    while True:
+       c = s3gFile.read(1);
+       if c == '\0':
+          break;
+       else:
+          buildName += c;
+
+    return (steps[0],buildName)
+
+# Command table entries consist of:
+# * The key: the integer command code
+# * A tuple:
+#   * idx 0: the python struct description of the rest of the data,
+#            of a function that unpacks the remaining data from the
+#            stream
+#   * idx 1: either a format string that will take the tuple of unpacked
+#            data, or a function that takes the tuple as input and returns
+#            a string
+# REMINDER: all values are little-endian. Struct strings with multibyte
+# types should begin with "<".
+# For a refresher on Python struct syntax, see here:
+# http://docs.python.org/library/struct.html
+
+commandTable = {    
+    129: ("<iiiI","\t[129] Absolute move to (%i,%i,%i) at DDA %i"),
+    130: ("<iii","\t[130] Machine position set as (%i,%i,%i)"),
+    131: ("<BIH","\t[131] Home minimum on %X, feedrate %i, timeout %i s"),
+    132: ("<BIH","\t[132] Home maximum on %X, feedrate %i, timeout %i s"),
+    133: ("<I","\t[133] Delay of %i us"),
+    134: ("<B","\t[134] Switch to tool %i"),
+    135: ("<BHH","\t[135] Wait for tool %i (%i ms between polls, %i s timeout"),
+    136: (parseToolAction, printToolAction),
+    137: ("<B", "\t[137] Enable/disable axes %X"),
+    138: ("<H", "\t[138] User block on ID %i"),
+    139: ("<iiiiiI","\t[139] Absolute move to (%i,%i,%i,%i,%i) at DDA %i"),
+    140: ("<iiiii","\t[140] Extended Machine position set as (%i,%i,%i,%i,%i)"),
+    141: ("<BHH","\t[141] Wait for platform %i (%i ms between polls, %i s timeout)"),
+    142: ("<iiiiiIB","\t[142] Move to (%i,%i,%i,%i,%i) in %i us (relative: %X)"),
+    143: ("<b","\t[143] Store home position for axes %d"),
+    144: ("<b","\t[144] Recall home position for axes %d"),
+    145: ("<BB","\t[145] Set pot axis %i to %i"),
+    146: ("<BBBBB","\t[146] Set RGB led red %i, green %i, blue %i, blink rate %i, effect %i"),
+    147: ("<HHB","\t[147] Set beep, frequency %i, length %i, effect %i"),
+    148: ("<BHB","\t[148] Pause for button 0x%X, timeout %i s, timeout_bevavior %i"),
+    149: (parseDisplayMessageAction, "\t[149] Display message, options 0x%X at %i,%i timeout %i\n    %s"),
+    150: ("<BB","\t[150] Set build percent %i%%, ignore %i"),
+    151: ("<B","\t[151] Queue song %i"),
+    152: ("<B","\t[152] Reset to factory, options 0x%X"),
+    153: (parseBuildStartNotificationAction, "\t[153] Start build, steps %i: %s"),
+    154: ("<B","\t[154] End build, flags 0x%X"),
+    155: ("<iiiiiIBfh","\t[155] Move to (%i,%i,%i,%i,%i) dda_rate: %i (relative: %X) distance: %f feedrateX64: %i"),
+    156: ("<B","\t[156] Set acceleration to %i"),
+    157: ("<BBBIHHIIB","\t[157] Stream version %i.%i (%i %i %i %i %i %i %i)"),
+}
+
+def parseNextCommand():
+    """Parse and handle the next command.  Returns
+    True for success, False on EOF, and raises an
+    exception on corrupt data."""
+    global s3gFile
+    commandStr = s3gFile.read(1)
+    if len(commandStr) == 0:
+        print "EOF"
+        return False
+    sys.stdout.write(str(lineNumber) + ': ')
+    (command) = struct.unpack("B",commandStr)
+    (parse, disp) = commandTable[command[0]]
+    if type(parse) == type(""):
+        packetLen = struct.calcsize(parse)
+        packetData = s3gFile.read(packetLen)
+        if len(packetData) != packetLen:
+            raise "Packet incomplete"
+        parsed = struct.unpack(parse,packetData)
+    else:
+        parsed = parse()
+    if type(disp) == type(""):
+        print disp % parsed
+    else:
+        disp(parsed)
+    return True
+
+s3gFile = open(sys.argv[1],'rb')
+lineNumber = 0
+while parseNextCommand():
+    lineNumber  = lineNumber + 1