diff --git a/animations/fpmath_patterns.c b/animations/fpmath_patterns.c
index 4f00a69..6e23b52 100644
--- a/animations/fpmath_patterns.c
+++ b/animations/fpmath_patterns.c
@@ -1,30 +1,277 @@
-#include <math.h> // Floating point math is dog slow on AVR, but I don't care.
-#include <string.h>
+/**
+ * Routines for drawing patterns generated by fixed point math functions.
+ */
+
 #include <assert.h>
+#include <stdint.h>
+#include <string.h>
 #include "../config.h"
 #include "../pixel.h"
 #include "../util.h"
 #include "fpmath_patterns.h"
 
+/**
+ * \defgroup fixedpoint Fixed-point based animated plasma patterns.
+ */
+/*@{*/
+
+/**
+ * Double buffering helps in reducing the effect of visibly redrawing every
+ * frame. With this option turned on, a frame is rendered into an off-screen
+ * buffer first and then copied to the actual frame buffer in one piece.
+ * However, given the borg's graphics architecture, half painted frames may
+ * still occur, but they are barely noticeable with this option enabled.
+ *
+ * Turn this off (#undef DOUBLE_BUFFERING) if you prefer speed over beauty.
+ */
 #define DOUBLE_BUFFERING
-#ifdef DOUBLE_BUFFERING
-#define BUFFER pixmap_buffer
+
+
+#ifdef LOW_PRECISION
+	#undef LOW_PRECISION
+#endif
+
+#if NUM_COLS <= 16 && NUM_ROWS <= 16
+	/**
+	 * Low precision means that we use Q10.5 values and 16 bit types for almost
+	 * every calculation (with multiplication and division as notable exceptions
+	 * as they and their interim results utilize 32 bit).
+	 *
+	 * Use this precision mode with care as image quality will suffer
+	 * noticeably. It produces leaner and faster code, though. This mode should
+	 * not be used with resolutions higher than 16x16 as overflows are likely to
+	 * occur in interim calculations.
+	 *
+	 * Normal precision (i.e. #undef LOW_PRECISION) conforms to Q7.8 with the
+	 * ability to store every interim result as Q23.8. Most operations like
+	 * square root, sine, cosine, multiplication etc. utilize 32 bit types.
+	 */
+	#define LOW_PRECISION
+#endif
+
+#ifdef LOW_PRECISION
+	/** This is the type we expect ordinary integers to be. */
+	typedef int16_t  ordinary_int_t;
+	/** This is the type which we use for fixed point values. */
+	typedef int16_t  fixp_t;
+	/** This type covers arguments of fixSin() and fixCos(). */
+	typedef int16_t  fixp_trig_t;
+	/** This type covers interim results of fixed point operations. */
+	typedef uint32_t  fixp_interim_t;
+	/** This type covers interim results of the fixed point sqrt() function. */
+	typedef uint16_t ufixp_interim_t;
+	/** Amount of bits the fixed point sqrt() function can handle. */
+	#define SQRT_BITS 16
+
+	// NOTE: If you change the following values, don't forget to adapt the sine
+	// lookup table as well!
+
+	/** Multiply a number by this factor to convert it to a fixed point value.*/
+	#define FIX           32
+	/**	Amount of fractional bits of a value (i.e. ceil(log_2(FIX))). */
+	#define FIX_FRACBITS  5
+	/**
+	 * The amount of temporal quantization steps of the sine lookup table. It
+	 * must be a divisor of (FIX * 2 * pi) and this divisor must be divisable by
+	 * 4 itself. Approximate this value as close as possible to keep rounding
+	 * errors at a minimum.
+	 */
+	#define FIX_SIN_COUNT  200
+	/** The rounded down quotient of (FIX * 2 * pi) and FIX_SIN_COUNT */
+	#define FIX_SIN_DIVIDER 1
+
+	/** Type of the lookup table elements. */
+	typedef uint8_t lut_t;
+
+	/**
+	 * Lookup table of fractional parts which model the first quarter of a
+	 * sine period. The rest of that period is calculated by mirroring those
+	 * values. These values are intended for Q5 types.
+	 */
+	static lut_t const fix_sine_lut[FIX_SIN_COUNT / 4] =
+			{ 0,  1,  2,  3,  4,  5,  6,  7,
+			  8,  9, 10, 11, 12, 13, 14, 15,
+			 15, 16, 17, 18, 19, 20, 20, 21,
+			 22, 22, 23, 24, 24, 25, 26, 26,
+			 27, 27, 28, 28, 29, 29, 29, 30,
+			 30, 30, 31, 31, 31, 31, 31, 31,
+			 31, 31};
 #else
-#define BUFFER pixmap
+	/** This is the type we expect ordinary integers to be. */
+	typedef int16_t  ordinary_int_t;
+	/** This is the type which we use for fixed point values. */
+	typedef int16_t  fixp_t;
+	/** This type covers arguments of fixSin() and fixCos(). */
+	typedef int32_t  fixp_trig_t;
+	/** This type covers interim results of fixed point operations. */
+	typedef int32_t  fixp_interim_t;
+	/** This type covers interim results of the fixed point sqrt() function. */
+	typedef uint32_t ufixp_interim_t;
+	/** Amount of bits the fixed point sqrt() function can handle. */
+	#define SQRT_BITS 32
+
+	// NOTE: If you change the following values, don't forget to adapt the sine
+	// lookup table as well!
+
+	/** Multiply a number by this factor to convert it to a fixed point value.*/
+	#define FIX           256
+	/**	Amount of fractional bits of a value (i.e. ceil(log_2(FIX))). */
+	#define FIX_FRACBITS  8
+	/**
+	 * The amount of temporal quantization steps of the sine lookup table. It
+	 * must be a divisor of (FIX * 2 * pi) and this divisor must be divisable by
+	 * 4 itself. Approximate this value as close as possible to keep rounding
+	 * errors at a minimum.
+	 */
+	#define FIX_SIN_COUNT  200
+	/** The rounded down quotient of (FIX * 2 * pi) and FIX_SIN_COUNT */
+	#define FIX_SIN_DIVIDER 8
+
+	/** Type of the lookup table elements. */
+	typedef uint8_t lut_t;
+
+	/**
+	 * Lookup table of fractional parts which model the first quarter of a
+	 * sine period. The rest of that period is calculated by mirroring those
+	 * values. These values are intended for Q8 types.
+	 */
+	static lut_t const fix_sine_lut[FIX_SIN_COUNT / 4] =
+			{  0,   9,  17,  24,  32,  40,  48,  56,
+			  64,  72,  79,  87,  94, 102, 109, 116,
+			 123, 130, 137, 144, 150, 157, 163, 169,
+			 175, 181, 186, 192, 197, 202, 207, 211,
+			 216, 220, 224, 228, 231, 235, 238, 240,
+			 243, 245, 247, 249, 251, 252, 253, 254,
+			 255, 255};
+
 #endif
 
 
+/** The ordinary pi constant. */
+#define PI                  3.14159265358979323846
+/** Fixed point version of (pi / 2). */
+#define FIX_PI_2            ((fixp_t)(PI * FIX / 2))
+/** Fixed point version of pi. */
+#define FIX_PI              ((fixp_t)(PI * FIX))
+/** Fixed point version of (2 * pi). */
+#define FIX_2PI             ((fixp_t)(2 * PI * FIX))
+
+
 /**
- * Pointer to a function which return a value depending on two-dimensional
- * coordinates and a "step" value.
- * @param x x-coordinate
- * @param y y-coordinate
- * @param t a step value which changes for each frame, allowing for animations
- * @return
+ * Scales an ordinary integer up to its fixed point format.
+ * @param a an ordinary integer to be scaled up
+ * @return The given value in fixed point format.
  */
-typedef unsigned char (*fpmath_pattern_func_t)(unsigned char const x,
-                                               unsigned char const y,
-                                               double t);
+inline static fixp_t fixScaleUp(ordinary_int_t a)
+{
+	return (fixp_t)a * FIX;
+}
+
+
+/**
+ * Scales a fixed point value down to an ordinary integer (omitting the
+ * fractional part).
+ * @param a fixed point value to be scaled down
+ * @return The given value in fixed point format.
+ */
+inline static ordinary_int_t fixScaleDown(fixp_t const a)
+{
+	return a / FIX;
+}
+
+
+/**
+ * Multiplies two fixed point values.
+ * @param a operand a
+ * @param b operand b
+ * @return Product of a and b.
+ */
+inline static fixp_interim_t fixMul(fixp_t const a, fixp_t const b)
+{
+	return ((fixp_interim_t)a * (fixp_interim_t)b) / FIX;
+}
+
+
+/**
+ * Divides two fixed point values.
+ * @param a operand a
+ * @param b operand b
+ * @return Quotient of a and b.
+ */
+inline static fixp_t fixDiv(fixp_interim_t const a, fixp_interim_t const b)
+{
+	return (a * FIX) / b;
+}
+
+
+/**
+ * Fixed point variant of the sine function which receives a fixed point angle
+ * (radian). It uses a lookup table which models the first quarter of a full
+ * sine period and calculates the rest from that quarter.
+ * @param angle fixed point radian value
+ * @return Result of the sine function normalized to a range from -FIX to FIX.
+ */
+static fixp_t fixSin(fixp_t const fAngle)
+{
+	// convert given angle to its corresponding lookup table quantization step
+	ordinary_int_t nNormAng = fAngle / FIX_SIN_DIVIDER;
+	// trim that value so that it fits into a range between [0, FIX_SIN_COUNT]
+	nNormAng = (nNormAng - (nNormAng / FIX_SIN_COUNT *	FIX_SIN_COUNT) +
+			FIX_SIN_COUNT) % FIX_SIN_COUNT;
+
+	uint8_t nIndex = nNormAng % (FIX_SIN_COUNT / 2);
+	if (nIndex >= (FIX_SIN_COUNT / 4))
+	{
+		nIndex = (FIX_SIN_COUNT / 2 - 1) - nIndex;
+	}
+	assert(nIndex < (FIX_SIN_COUNT / 4));
+
+	return ((fixp_t)fix_sine_lut[nIndex]) *
+			(nNormAng < (FIX_SIN_COUNT / 2) ? 1 : -1);
+}
+
+
+/**
+ * Fixed point variant of the cosine function which takes a fixed point angle
+ * (radian). It adds FIX_PI_2 to the given angle and consults the fixSin()
+ * function for the final result.
+ * @param angle fixed point radian value
+ * @return Result of the cosine function normalized to a range from -FIX to FIX.
+ */
+static fixp_t fixCos(fixp_t const angle)
+{
+	return fixSin(angle + FIX_PI_2);
+}
+
+
+/**
+ * Fixed point square root algorithm as proposed by Ken Turkowski:
+ * http://www.realitypixels.com/turk/computergraphics/FixedSqrt.pdf
+ * @param radicant we want the square root of
+ * @return The square root of the given value.
+ */
+static fixp_t fixSqrt(ufixp_interim_t const a)
+{
+	ufixp_interim_t nRoot, nRemainingHigh, nRemainingLow, nTestDiv, nCount;
+	nRoot = 0;  // clear root
+	nRemainingHigh = 0; // clear high part of partial remainder
+	nRemainingLow = a; // get argument into low part of partial remainder
+	nCount = (SQRT_BITS / 2 - 1) + (FIX_FRACBITS >> 1); // load loop counter
+	do
+	{
+		nRemainingHigh =
+				(nRemainingHigh << 2) | (nRemainingLow >> (SQRT_BITS - 2));
+		nRemainingLow <<= 2; // get 2 bits of the argument
+		nRoot <<= 1;  // get ready for the next bit in the root
+		nTestDiv = (nRoot << 1) + 1; // test radical
+		if (nRemainingHigh >= nTestDiv)
+		{
+			nRemainingHigh -= nTestDiv;
+			nRoot++;
+		}
+	} while (nCount-- != 0);
+	return (nRoot);
+}
 
 
 /**
@@ -33,41 +280,69 @@ typedef unsigned char (*fpmath_pattern_func_t)(unsigned char const x,
  * @param y1 y coordinate of the first point
  * @param x2 x coordinate of the second point
  * @param y2 y coordinate of the second point
- * @return distance between the points
+ * @return The distance between the given coordinates.
  */
-static double dist(double x1, double y1, double x2, double y2)
+static fixp_t fixDist(fixp_t const x1,
+                      fixp_t const y1,
+                      fixp_t const x2,
+                      fixp_t const y2)
 {
-	return sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2)));
+	return fixSqrt(fixMul((x1 - x2), (x1 - x2)) + fixMul((y1 - y2), (y1 - y2)));
 }
 
 
 /**
- * Draws an animated two dimensional graph for a given function f(x,y,t).
- * @param t_start start value for the function's time variable
- * @param t_stop stop value for the function's time variable
- * @param t_delta value by which the function's timing variable gets incremented
- * @param frame_delay frame delay in ms
- * @param fpPattern function which generates a pattern depending on x, y, t
+ * This pointer type covers functions which return a brightness value for the
+ * given coordinates and a "step" value. This actually results in a more or less
+ * "beautiful" pattern.
+ * @param x x-coordinate
+ * @param y y-coordinate
+ * @param t step value which changes for each frame, allowing for animations
+ * @param r pointer to persistent data required by the pattern function
+ * @return The brightness value (0 < n <= NUM_PLANES) of the given coordinate.
  */
-static void fpmath_pattern(double const t_start,
-                           double const t_stop,
-                           double const t_delta,
-                           unsigned int const frame_delay,
-                           fpmath_pattern_func_t fpPattern)
+typedef unsigned char (*fpmath_pattern_func_t)(unsigned char const x,
+                                               unsigned char const y,
+                                               fixp_t const t,
+                                               void *const r);
+
+#ifdef DOUBLE_BUFFERING
+#    define BUFFER pixmap_buffer
+#else
+#    define BUFFER pixmap
+#endif
+
+
+/**
+ * Draws an animated two dimensional graph for a given function f(x, y, t).
+ * @param t_start start value for the function's step variable
+ * @param t_stop stop value for the function's step variable
+ * @param t_delta value by which the function's step variable gets incremented
+ * @param frame_delay frame delay in milliseconds
+ * @param fpPattern function which generates a pattern depending on x, y and t
+ * @param r pointer to persistent data required by the fpPattern function
+ */
+static void fixPattern(fixp_t const t_start,
+                       fixp_t const t_stop,
+                       fixp_t const t_delta,
+                       int const frame_delay,
+                       fpmath_pattern_func_t fpPattern,
+                       void *r)
 {
 #ifdef DOUBLE_BUFFERING
 	// double buffering to reduce half painted pictures
 	unsigned char pixmap_buffer[NUMPLANE][NUM_ROWS][LINEBYTES];
 #endif
 
-	for (double t = t_start; t < t_stop; t += t_delta)
+	for (fixp_t t = t_start; t < t_stop; t += t_delta)
 	{
 		for (unsigned char y = 0; y < NUM_ROWS; ++y)
 		{
 			unsigned char nChunk[NUMPLANE + 1][LINEBYTES] = {{0}};
 			for (unsigned char x = 0; x < (LINEBYTES * 8); ++x)
 			{
-				nChunk[fpPattern(x, y, t) - 1][x / 8u] |= shl_table[x % 8u];
+				assert (y < 16);
+				nChunk[fpPattern(x, y, t, r) - 1][x / 8u] |= shl_table[x % 8u];
 			}
 			for (unsigned char p = NUMPLANE; p--;)
 			{
@@ -89,71 +364,133 @@ static void fpmath_pattern(double const t_start,
 
 
 #ifdef ANIMATION_PLASMA
-#define PLASMA_X (1.0 / (NUM_COLS / (2.0 * M_PI)))
 
 /**
- * Draws a simple plasma like pattern.
+ * This type maintains values relevant for the Plasma animation which need to be
+ * persistent over consecutive invocations.
  */
-static unsigned char fpmath_plasma(unsigned char x, unsigned char y, double t)
+typedef struct fixp_plasma_s
+{
+	fixp_t fFunc1[NUM_COLS]; /**< Result of 1st trig. func. depending on x. */
+	fixp_t fFunc2CosArg; /**< Arg. of 2st trig. func. depending on the frame. */
+	fixp_t fFunc2SinArg; /**< Arg. of 2st trig. func. depending on the frame. */
+} fixp_plasma_t;
+
+
+/**
+ * Draws a plasma like pattern (sort of... four shades of grey are pretty
+ * scarce for a neat plasma animation).
+ * @param x x-coordinate
+ * @param y y-coordinate
+ * @param t step value which changes for each frame, allowing for animations
+ * @param r pointer to persistent interim results
+ * @return The brightness value (0 < n <= NUM_PLANES) of the given coordinate.
+ */
+static unsigned char fixAnimPlasma(unsigned char const x,
+                                   unsigned char const y,
+                                   fixp_t const t,
+                                   void *const r)
 {
 	assert(x < NUM_COLS);
 	assert(y < NUM_ROWS);
 
-	static double fFunc1[NUM_COLS];
-	static double fFunc2CosArg;
-	static double fFunc2SinArg;
+	// scaling factor
+	static fixp_t const fPlasmaX = (2 * PI * FIX) / NUM_COLS;
+
+	// reentrant data
+	fixp_plasma_t *const p = (fixp_plasma_t *)r;
+
 	if (x == 0 && y == 0)
 	{
-		fFunc2CosArg = NUM_ROWS * cos(t) + NUM_ROWS;
-		fFunc2SinArg = NUM_COLS * sin(t) + NUM_COLS;
+		p->fFunc2CosArg = NUM_ROWS * fixCos(t) + fixScaleUp(NUM_ROWS);
+		p->fFunc2SinArg = NUM_COLS * fixSin(t) + fixScaleUp(NUM_COLS);
 	}
 	if (y == 0)
 	{
-		fFunc1[x] = sin(x * PLASMA_X + t);
+		p->fFunc1[x] = fixSin(fixMul(fixScaleUp(x), fPlasmaX) + t);
 	}
 
-	return (fFunc1[x] + sin(dist(x, y, fFunc2SinArg, fFunc2CosArg) * PLASMA_X)
-			+ 2) * (NUMPLANE - 1) / 2;
+	fixp_t const fFunc2 = fixSin(fixMul(fixDist(fixScaleUp(x), fixScaleUp(y),
+			p->fFunc2SinArg, p->fFunc2CosArg), fPlasmaX));
+
+	uint8_t const nRes = fixScaleDown(fixDiv(fixMul(p->fFunc1[x] + fFunc2 +
+			fixScaleUp(2), fixScaleUp(NUMPLANE - 1)), fixScaleUp(2)));
+	assert (nRes <= 3);
+
+	return nRes;
 }
 
+
 void plasma(void)
 {
+	fixp_plasma_t r;
 #ifndef __AVR__
-	fpmath_pattern(0.0, 75, 0.1, 80, fpmath_plasma);
+	fixPattern(0, fixScaleUp(75), 0.1 * FIX, 80, fixAnimPlasma, &r);
 #else
-	fpmath_pattern(0.0, 60.0, 0.1, 1, fpmath_plasma);
-#endif
+	fixPattern(0, fixScaleUp(60), 0.1 * FIX, 1, fixAnimPlasma, &r);
+#endif /* __AVR__ */
 }
-#endif
+
+#endif /* ANIMATION_PLASMA */
 
 
 #ifdef ANIMATION_PSYCHEDELIC
+
+/**
+ * This type maintains values relevant for the Psychedelic animation which need
+ * to be persistent over consecutive invocations.
+ */
+typedef struct fixp_psychedelic_s
+{
+	fixp_t fCos;         /** column factor for the circle calculation */
+	fixp_t fSin;         /** row factor for the circle calculation */
+	fixp_interim_t ft10; /** value involved in rotating the animation's center*/
+} fixp_psychedelic_t;
+
+
 /**
  * Draws flowing circular waves with a rotating center.
+ * @param x x-coordinate
+ * @param y y-coordinate
+ * @param t step value which changes for each frame, allowing for animations
+ * @param r pointer to persistent interim results
+ * @return The brightness value (0 < n <= NUM_PLANES) of the given coordinate.
  */
-static unsigned char fpmath_psycho(unsigned char x, unsigned char y, double t)
+static unsigned char fixAnimPsychedelic(unsigned char const x,
+                                        unsigned char const y,
+                                        fixp_t const t,
+                                        void *const r)
 {
 	assert(x < NUM_COLS);
 	assert(y < NUM_ROWS);
+	fixp_psychedelic_t *p = (fixp_psychedelic_t *)r;
 
-	static double fCosinus;
-	static double fSinus;
-	static double t10;
 	if (x == 0 && y == 0)
 	{
-		fCosinus = NUM_COLS * cos(t);
-		fSinus = NUM_ROWS * sin(t);
-		t10 = t * 10;
+		p->fCos = NUM_COLS/2 * fixCos(t);
+		p->fSin = NUM_ROWS/2 * fixSin(t);
+		p->ft10 = fixMul(t, fixScaleUp(10));
 	}
-	return (sin(dist(x, y, fCosinus, fSinus) - t10) + 1) * (NUMPLANE - 1);
+
+	uint8_t const nResult =
+			fixScaleDown(fixMul(fixSin((fixp_interim_t)fixDist(fixScaleUp(x),
+			fixScaleUp(y), p->fCos, p->fSin) - p->ft10) + fixScaleUp(1),
+			fixScaleUp(NUMPLANE - 1)));
+	assert(nResult <= NUMPLANE);
+
+	return nResult;
 }
 
 void psychedelic(void)
 {
+	fixp_psychedelic_t r;
 #ifndef __AVR__
-	fpmath_pattern(0.0, 75, 0.1, 80, fpmath_psycho);
+	fixPattern(0, fixScaleUp(75), 0.1 * FIX, 80, fixAnimPsychedelic, &r);
 #else
-	fpmath_pattern(0.0, 60.0, 0.1, 1, fpmath_psycho);
-#endif
+	fixPattern(0, fixScaleUp(60), 0.1 * FIX, 15, fixAnimPsychedelic, &r);
+#endif /* __AVR__ */
 }
-#endif
+
+#endif /* ANIMATION_PSYCHEDELIC */
+
+/*@}*/