diff --git a/dda.c b/dda.c
index 0733c3e..0b098d7 100644
--- a/dda.c
+++ b/dda.c
@@ -209,6 +209,7 @@ void dda_create(DDA *dda, TARGET *target) {
 		//         distance * 2400 .. * F_CPU / 40000 so we can move a distance of up to 1800mm without overflowing
 		uint32_t move_duration = ((distance * 2400) / dda->total_steps) * (F_CPU / 40000);
 
+		#ifdef ACCELERATION_REPRAP
 		// c is initial step time in IOclk ticks
 		dda->c = (move_duration / startpoint.F) << 8;
 
@@ -269,6 +270,9 @@ void dda_create(DDA *dda, TARGET *target) {
 		}
 		else
 			dda->accel = 0;
+		#else
+		dda->c = (move_duration / target->F) << 8;
+		#endif
 	}
 
 	if (debug_flags & DEBUG_DDA)
@@ -389,6 +393,7 @@ void dda_step(DDA *dda) {
 		sei();
 	#endif
 
+	#ifdef ACCELERATION_REPRAP
 	// linear acceleration magic, courtesy of http://www.embedded.com/columns/technicalinsights/56800129?printable=true
 	if (dda->accel) {
 		if (
@@ -405,6 +410,7 @@ void dda_step(DDA *dda) {
 		}
 		// else we are already at target speed
 	}
+	#endif
 
 	if (did_step) {
 		// we stepped, reset timeout
diff --git a/dda.h b/dda.h
index 2248f10..78863ce 100644
--- a/dda.h
+++ b/dda.h
@@ -29,7 +29,9 @@ typedef struct {
 			// status fields
 			uint8_t						nullmove			:1;
 			uint8_t						live					:1;
+			#ifdef ACCELERATION_REPRAP
 			uint8_t						accel					:1;
+			#endif
 
 			// wait for temperature to stabilise flag
 			uint8_t						waitfor_temp	:1;
@@ -60,8 +62,10 @@ typedef struct {
 
 	// linear acceleration variables: c and end_c are 24.8 fixed point timer values, n is the tracking variable
 	uint32_t					c;
+	#ifdef ACCELERATION_REPRAP
 	uint32_t					end_c;
 	int32_t						n;
+	#endif
 } DDA;
 
 /*
diff --git a/gcode.c b/gcode.c
index a4770a3..b3063d7 100644
--- a/gcode.c
+++ b/gcode.c
@@ -693,7 +693,11 @@ void process_gcode_command(GCODE_COMMAND *gcmd) {
 				serial_writestr_P(PSTR(",F:"));
 				serwrite_int32(movebuffer[mb_tail].endpoint.F);
 				serial_writestr_P(PSTR(",c:"));
+				#ifdef ACCELERATION_REPRAP
 				serwrite_uint32(movebuffer[mb_tail].end_c);
+				#else
+				serwrite_uint32(movebuffer[mb_tail].c);
+				#endif
 				serial_writestr_P(PSTR("}\n"));
 
 				print_queue();
diff --git a/machine.h b/machine.h
index 033ec7c..49a981a 100644
--- a/machine.h
+++ b/machine.h
@@ -36,6 +36,11 @@
 #define	TEMP_HYSTERESIS		20
 #define	TEMP_RESIDENCY_TIME	60
 
+// acceleration, reprap style. Each movement starts at the speed of
+// the previous command and accelerates or decelerates linearly
+// to reach target speed at the end of the movement.
+#define ACCELERATION_REPRAP
+
 // --------------------------------------------------------------------------
 // you shouldn't need to edit something below this line