diff --git a/dda.c b/dda.c
index 545a6be..b037ba4 100644
--- a/dda.c
+++ b/dda.c
@@ -50,127 +50,6 @@ TARGET current_position __attribute__ ((__section__ (".bss")));
 /// \brief numbers for tracking the current state of movement
 MOVE_STATE move_state __attribute__ ((__section__ (".bss")));
 
-/*
-	utility functions
-*/
-
-// courtesy of http://www.flipcode.com/archives/Fast_Approximate_Distance_Functions.shtml
-/*! linear approximation 2d distance formula
-	\param dx distance in X plane
-	\param dy distance in Y plane
-	\return 3-part linear approximation of \f$\sqrt{\Delta x^2 + \Delta y^2}\f$
-
-	see http://www.flipcode.com/archives/Fast_Approximate_Distance_Functions.shtml
-*/
-uint32_t approx_distance( uint32_t dx, uint32_t dy )
-{
-	uint32_t min, max, approx;
-
-	if ( dx < dy )
-	{
-		min = dx;
-		max = dy;
-	} else {
-		min = dy;
-		max = dx;
-	}
-
-	approx = ( max * 1007 ) + ( min * 441 );
-	if ( max < ( min << 4 ))
-		approx -= ( max * 40 );
-
-	// add 512 for proper rounding
-	return (( approx + 512 ) >> 10 );
-}
-
-// courtesy of http://www.oroboro.com/rafael/docserv.php/index/programming/article/distance
-/*! linear approximation 3d distance formula
-	\param dx distance in X plane
-	\param dy distance in Y plane
-	\param dz distance in Z plane
-	\return 3-part linear approximation of \f$\sqrt{\Delta x^2 + \Delta y^2 + \Delta z^2}\f$
-
-	see http://www.oroboro.com/rafael/docserv.php/index/programming/article/distance
-*/
-uint32_t approx_distance_3( uint32_t dx, uint32_t dy, uint32_t dz )
-{
-	uint32_t min, med, max, approx;
-
-	if ( dx < dy )
-	{
-		min = dy;
-		med = dx;
-	} else {
-		min = dx;
-		med = dy;
-	}
-
-	if ( dz < min )
-	{
-		max = med;
-		med = min;
-		min = dz;
-	} else if ( dz < med ) {
-		max = med;
-		med = dz;
-	} else {
-		max = dz;
-	}
-
-	approx = ( max * 860 ) + ( med * 851 ) + ( min * 520 );
-	if ( max < ( med << 1 )) approx -= ( max * 294 );
-	if ( max < ( min << 2 )) approx -= ( max * 113 );
-	if ( med < ( min << 2 )) approx -= ( med *  40 );
-
-	// add 512 for proper rounding
-	return (( approx + 512 ) >> 10 );
-}
-
-/*!
-	integer square root algorithm
-	\param a find square root of this number
-	\return sqrt(a - 1) < returnvalue <= sqrt(a)
-
-	see http://www.embedded-systems.com/98/9802fe2.htm
-*/
-// courtesy of http://www.embedded-systems.com/98/9802fe2.htm
-uint16_t int_sqrt(uint32_t a) {
-	uint32_t rem = 0;
-	uint32_t root = 0;
-	uint16_t i;
-
-	for (i = 0; i < 16; i++) {
-		root <<= 1;
-		rem = ((rem << 2) + (a >> 30));
-		a <<= 2;
-		root++;
-		if (root <= rem) {
-			rem -= root;
-			root++;
-		}
-		else
-			root--;
-	}
-	return (uint16_t) ((root >> 1) & 0xFFFFL);
-}
-
-// this is an ultra-crude pseudo-logarithm routine, such that:
-// 2 ^ msbloc(v) >= v
-/*! crude logarithm algorithm
-	\param v value to find \f$log_2\f$ of
-	\return floor(log(v) / log(2))
-*/
-const uint8_t	msbloc (uint32_t v) {
-	uint8_t i;
-	uint32_t c;
-	for (i = 31, c = 0x80000000; i; i--) {
-		if (v & c)
-			return i;
-		c >>= 1;
-	}
-	return 0;
-}
-
 /*! Inititalise DDA movement structures
 */
 void dda_init(void) {
diff --git a/dda.h b/dda.h
index d8fcc8b..37cc69e 100644
--- a/dda.h
+++ b/dda.h
@@ -159,12 +159,6 @@ extern TARGET current_position;
 	methods
 */
 
-uint32_t approx_distance( uint32_t dx, uint32_t dy )								__attribute__ ((hot));
-uint32_t approx_distance_3( uint32_t dx, uint32_t dy, uint32_t dz )	__attribute__ ((hot));
-
-// const because return value is always the same given the same v
-const uint8_t	msbloc (uint32_t v)																		__attribute__ ((const));
-
 // initialize dda structures
 void dda_init(void);
 
diff --git a/dda_maths.c b/dda_maths.c
index f2144bb..fe613a5 100644
--- a/dda_maths.c
+++ b/dda_maths.c
@@ -1,6 +1,6 @@
 
 /** \file
-	\brief Mathematic algorithms for the digital differential analyser (DDA).
+  \brief Mathematic algorithms for the digital differential analyser (DDA).
 */
 
 #include "dda_maths.h"
@@ -63,3 +63,114 @@ const int32_t muldivQR(int32_t multiplicand, uint32_t qn, uint32_t rn,
   return negative_flag ? -((int32_t)quotient) : (int32_t)quotient;
 }
 
+// courtesy of http://www.flipcode.com/archives/Fast_Approximate_Distance_Functions.shtml
+/*! linear approximation 2d distance formula
+  \param dx distance in X plane
+  \param dy distance in Y plane
+  \return 3-part linear approximation of \f$\sqrt{\Delta x^2 + \Delta y^2}\f$
+
+  see http://www.flipcode.com/archives/Fast_Approximate_Distance_Functions.shtml
+*/
+uint32_t approx_distance(uint32_t dx, uint32_t dy) {
+  uint32_t min, max, approx;
+
+  if ( dx < dy ) {
+    min = dx;
+    max = dy;
+  } else {
+    min = dy;
+    max = dx;
+  }
+
+  approx = ( max * 1007 ) + ( min * 441 );
+  if ( max < ( min << 4 ))
+    approx -= ( max * 40 );
+
+  // add 512 for proper rounding
+  return (( approx + 512 ) >> 10 );
+}
+
+// courtesy of http://www.oroboro.com/rafael/docserv.php/index/programming/article/distance
+/*! linear approximation 3d distance formula
+  \param dx distance in X plane
+  \param dy distance in Y plane
+  \param dz distance in Z plane
+  \return 3-part linear approximation of \f$\sqrt{\Delta x^2 + \Delta y^2 + \Delta z^2}\f$
+
+  see http://www.oroboro.com/rafael/docserv.php/index/programming/article/distance
+*/
+uint32_t approx_distance_3(uint32_t dx, uint32_t dy, uint32_t dz) {
+  uint32_t min, med, max, approx;
+
+  if ( dx < dy ) {
+    min = dy;
+    med = dx;
+  } else {
+    min = dx;
+    med = dy;
+  }
+
+  if ( dz < min ) {
+    max = med;
+    med = min;
+    min = dz;
+  } else if ( dz < med ) {
+    max = med;
+    med = dz;
+  } else {
+    max = dz;
+  }
+
+  approx = ( max * 860 ) + ( med * 851 ) + ( min * 520 );
+  if ( max < ( med << 1 )) approx -= ( max * 294 );
+  if ( max < ( min << 2 )) approx -= ( max * 113 );
+  if ( med < ( min << 2 )) approx -= ( med *  40 );
+
+  // add 512 for proper rounding
+  return (( approx + 512 ) >> 10 );
+}
+
+/*!
+  integer square root algorithm
+  \param a find square root of this number
+  \return sqrt(a - 1) < returnvalue <= sqrt(a)
+
+  see http://www.embedded-systems.com/98/9802fe2.htm
+*/
+// courtesy of http://www.embedded-systems.com/98/9802fe2.htm
+uint16_t int_sqrt(uint32_t a) {
+  uint32_t rem = 0;
+  uint32_t root = 0;
+  uint16_t i;
+
+  for (i = 0; i < 16; i++) {
+    root <<= 1;
+    rem = ((rem << 2) + (a >> 30));
+    a <<= 2;
+    root++;
+    if (root <= rem) {
+      rem -= root;
+      root++;
+    }
+    else
+      root--;
+  }
+  return (uint16_t) ((root >> 1) & 0xFFFFL);
+}
+
+// this is an ultra-crude pseudo-logarithm routine, such that:
+// 2 ^ msbloc(v) >= v
+/*! crude logarithm algorithm
+  \param v value to find \f$log_2\f$ of
+  \return floor(log(v) / log(2))
+*/
+const uint8_t msbloc (uint32_t v) {
+  uint8_t i;
+  uint32_t c;
+  for (i = 31, c = 0x80000000; i; i--) {
+    if (v & c)
+      return i;
+    c >>= 1;
+  }
+  return 0;
+}
diff --git a/dda_maths.h b/dda_maths.h
index de819ab..28028a9 100644
--- a/dda_maths.h
+++ b/dda_maths.h
@@ -50,4 +50,17 @@ inline int32_t um_to_steps_e(int32_t distance) {
                     STEPS_PER_M_E % 1000000UL, 1000000UL);
 }
 
+// approximate 2D distance
+uint32_t approx_distance(uint32_t dx, uint32_t dy);
+
+// approximate 3D distance
+uint32_t approx_distance_3(uint32_t dx, uint32_t dy, uint32_t dz);
+
+// integer square root algorithm
+uint16_t int_sqrt(uint32_t a);
+
+// this is an ultra-crude pseudo-logarithm routine, such that:
+// 2 ^ msbloc(v) >= v
+const uint8_t msbloc (uint32_t v);
+
 #endif	/* _DDA_MATHS_H */