diff --git a/lib/Charliplexing.cpp b/lib/Charliplexing.cpp
index 3d601cf..8e6ef3d 100644
--- a/lib/Charliplexing.cpp
+++ b/lib/Charliplexing.cpp
@@ -354,10 +354,10 @@ void LedSign::Flip(bool blocking)
 /** Clear the screen completely
  * @param set if 1 : make all led ON, if not set or 0 : make all led OFF
  */
-void LedSign::Clear(int set) {
-    for(int x=0;x<14;x++)  
-        for(int y=0;y<9;y++) 
-            Set(x,y,set);
+void LedSign::Clear(uint8_t c) {
+    for (uint8_t x=0; x<DISPLAY_COLS; x++)  
+        for (uint8_t y=0; y<DISPLAY_ROWS; y++) 
+            Set(x, y, c);
 }
 
 
@@ -366,9 +366,9 @@ void LedSign::Clear(int set) {
  * @param y is the y coordinate of the line to clear/light [0-8]
  * @param set if 1 : make all led ON, if not set or 0 : make all led OFF
  */
-void LedSign::Horizontal(int y, int set) {
-    for(int x=0;x<14;x++)  
-        Set(x,y,set);
+void LedSign::Horizontal(uint8_t y, uint8_t c) {
+    for (uint8_t x=0; x<DISPLAY_COLS; x++)  
+        Set(x, y, c);
 }
 
 
@@ -377,9 +377,9 @@ void LedSign::Horizontal(int y, int set) {
  * @param x is the x coordinate of the line to clear/light [0-13]
  * @param set if 1 : make all led ON, if not set or 0 : make all led OFF
  */
-void LedSign::Vertical(int x, int set) {
-    for(int y=0;y<9;y++)  
-        Set(x,y,set);
+void LedSign::Vertical(uint8_t x, uint8_t c) {
+    for (uint8_t y=0; y<DISPLAY_ROWS; y++)  
+        Set(x, y, c);
 }
 
 
@@ -399,8 +399,8 @@ void LedSign::Set(uint8_t x, uint8_t y, uint8_t c)
         c = SHADES-1;
 #endif
 
-    uint16_t mask = 1 << pgm_read_byte_near(&ledMap[x+y*14].high);
-    uint8_t cycle = pgm_read_byte_near(&ledMap[x+y*14].cycle);
+    uint16_t mask = 1 << pgm_read_byte_near(&ledMap[x+y*DISPLAY_COLS].high);
+    uint8_t cycle = pgm_read_byte_near(&ledMap[x+y*DISPLAY_COLS].cycle);
 
     uint16_t *p = &workBuffer->pixels[cycle*(SHADES-1)];
     int i;
diff --git a/lib/Charliplexing.h b/lib/Charliplexing.h
index a44b481..d85af3b 100644
--- a/lib/Charliplexing.h
+++ b/lib/Charliplexing.h
@@ -28,11 +28,10 @@ namespace LedSign
     extern void Init(uint8_t mode = SINGLE_BUFFER);
     extern void Set(uint8_t x, uint8_t y, uint8_t c = 1);
     extern void SetBrightness(uint8_t brightness);
-    extern volatile unsigned int tcnt2;
     extern void Flip(bool blocking = false);
-    extern void Clear(int set=0);
-    extern void Horizontal(int y, int set=0);
-    extern void Vertical(int x, int set=0);
+    extern void Clear(uint8_t c = 0);
+    extern void Horizontal(uint8_t y, uint8_t c = 0);
+    extern void Vertical(uint8_t x, uint8_t c = 0);
 };
 
 #endif
diff --git a/lib/Font.cpp b/lib/Font.cpp
index ff45161..72a60cf 100644
--- a/lib/Font.cpp
+++ b/lib/Font.cpp
@@ -117,14 +117,14 @@ const uint8_t* font2[] = { 0,  0,  0,  0,  0,  0,  letters_97 /*a*/,  letters_98
 #endif
 
 /* -----------------------------------------------------------------  */
-/** Draws a figure (0-9). You should call it with set=1, 
- * wait a little them call it again with set=0
+/** Draws a figure (0-9). You should call it with c=1, 
+ * wait a little them call it again with c=0
  * @param figure is the figure [0-9]
  * @param x,y coordinates, 
- * @param set is 1 or 0 to draw or clear it
+ * @param c is 1 or 0 to draw or clear it
  */
-uint8_t Font::Draw(unsigned char letter,int x,int y,int set) {
-  uint16_t maxx=0;
+uint8_t Font::Draw(unsigned char letter, uint8_t x, uint8_t y, uint8_t c) {
+  uint8_t maxx=0;
 
   uint8_t charCol;
   uint8_t charRow;
@@ -141,25 +141,22 @@ uint8_t Font::Draw(unsigned char letter,int x,int y,int set) {
     character = font[letter-fontMin];
 //  }
 
-  int i=0;
-
-  charCol = pgm_read_byte_near(character);
-  charRow = pgm_read_byte_near(character + 1);
+  charCol = pgm_read_byte_near(character++);
+  charRow = pgm_read_byte_near(character++);
 
   while (charRow!=9) {
     if (charCol>maxx) maxx=charCol;
     if (
-     charCol + x <14 && 
+     charCol + x <DISPLAY_COLS && 
      charCol + x >=0 && 
-     charRow + y <9 && 
+     charRow + y <DISPLAY_ROWS && 
      charRow + y >=0
     ) {
-        LedSign::Set(charCol + x, charRow+y, set);
+        LedSign::Set(charCol + x, charRow+y, c);
     } 
-    i+=2;
 
-    charCol = pgm_read_byte_near(character + i);
-    charRow = pgm_read_byte_near(character + 1 + i);
+    charCol = pgm_read_byte_near(character++);
+    charRow = pgm_read_byte_near(character++);
   }
   return maxx+2;
 }
@@ -169,10 +166,10 @@ uint8_t Font::Draw(unsigned char letter,int x,int y,int set) {
 /** Draw a figure in the other direction (rotated 90°)
  * @param figure is the figure [0-9]
  * @param x,y coordinates, 
- * @param set is 1 or 0 to draw or clear it
+ * @param c is 1 or 0 to draw or clear it
 */
-uint8_t Font::Draw90(unsigned char letter,int x,int y,int set) {
-  uint16_t maxx=0;
+uint8_t Font::Draw90(unsigned char letter, uint8_t x, uint8_t y, uint8_t c) {
+  uint8_t maxx=0;
 
   uint8_t charCol;
   uint8_t charRow;
@@ -189,28 +186,24 @@ uint8_t Font::Draw90(unsigned char letter,int x,int y,int set) {
     character = font[letter-fontMin];
 //  }
 
-  int i=0;
-
-  charCol = pgm_read_byte_near(character);
-  charRow = pgm_read_byte_near(character + 1);
+  charCol = pgm_read_byte_near(character++);
+  charRow = pgm_read_byte_near(character++);
 
   while (charRow!=9) {
     if (charCol>maxx) maxx=charCol;
     if (
-     charRow + x <14 && 
+     charRow + x <DISPLAY_COLS && 
      charRow + x >=0 && 
-     charCol + y <9 && 
+     charCol + y <DISPLAY_ROWS && 
      charCol + y >=0
     ) {
-        LedSign::Set(7 - charRow + x, charCol + y, set);
+        LedSign::Set(7 - charRow + x, charCol + y, c);
     } 
-    i+=2;
 
-    charCol = pgm_read_byte_near(character + i);
-    charRow = pgm_read_byte_near(character + 1 + i);
+    charCol = pgm_read_byte_near(character++);
+    charRow = pgm_read_byte_near(character++);
   }
   return maxx+2;
-
 }
 
 
diff --git a/lib/Font.h b/lib/Font.h
index 84dd77a..a9fef63 100644
--- a/lib/Font.h
+++ b/lib/Font.h
@@ -29,12 +29,8 @@
 
 namespace Font
 {
-
-extern uint8_t Draw(unsigned char letter,int x,int y,int set=1);
-
-extern uint8_t Draw90(unsigned char letter,int x,int y,int set=1);
-
+  extern uint8_t Draw(unsigned char letter, uint8_t x, uint8_t y, uint8_t c=1);
+  extern uint8_t Draw90(unsigned char letter, uint8_t x, uint8_t y, uint8_t c=1);
 }
 
 #endif
-