diff --git a/presets/c64/23matches.c b/presets/c64/23matches.c
index 1b9d2be8..186856b7 100644
--- a/presets/c64/23matches.c
+++ b/presets/c64/23matches.c
@@ -1,10 +1,5 @@
 
-#include <conio.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <peekpoke.h>
-#include <string.h>
-#include <c64.h>
+#include "common.h"
 #include <cbm_petscii_charmap.h>
 
 int matches;	// number of matches remaining
diff --git a/presets/c64/climber.c b/presets/c64/climber.c
index c776ea3f..b33d70ff 100644
--- a/presets/c64/climber.c
+++ b/presets/c64/climber.c
@@ -1,26 +1,20 @@
 
-#include <stdlib.h>
-#include <string.h>
-
-#include <c64.h>
-#include <joystick.h>
-
 //#resource "c64-sid.cfg"
 #define CFGFILE c64-sid.cfg
 
+#include "common.h"
+//#link "common.c"
+
+#include "sidplaysfx.h"
 //#resource "sidmusic1.bin"
 //#link "sidplaysfx.ca65"
-#include "sidplaysfx.h"
 
-//#link "rasterirq.ca65"
 #include "rasterirq.h"
+//#link "rasterirq.ca65"
 
 #include "bcd.h"
 //#link "bcd.c"
 
-#include "common.h"
-//#link "common.c"
-
 #include "scrolling.h"
 //#link "scrolling.c"
 
diff --git a/presets/c64/common.h b/presets/c64/common.h
index 2ff9501a..4ed05d4c 100644
--- a/presets/c64/common.h
+++ b/presets/c64/common.h
@@ -1,8 +1,14 @@
 #ifndef _COMMON_H
 #define _COMMON_H
 
-#include <c64.h>
+#include <conio.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <stdint.h>
+#include <peekpoke.h>
+#include <string.h>
+#include <c64.h>
+#include <joystick.h>
 
 typedef uint8_t byte;
 typedef uint16_t word;
@@ -14,8 +20,9 @@ typedef enum { false, true } bool;
 
 #define DEFAULT_SCREEN ((void*)0x400)
 
+#define wait_vblank waitvsync
+
 void raster_wait(byte line);
-void wait_vblank(void);
 
 char* get_vic_bank_start(void);
 
diff --git a/presets/c64/joymove.c b/presets/c64/joymove.c
index 3a8177fe..470ea76b 100644
--- a/presets/c64/joymove.c
+++ b/presets/c64/joymove.c
@@ -1,12 +1,5 @@
 
-#include <conio.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <peekpoke.h>
-#include <string.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <joystick.h>
+#include "common.h"
 
 /*{w:24,h:21,bpp:1,brev:1,count:1}*/
 const char SPRITE_DATA[64] = {
diff --git a/presets/c64/multilines.c b/presets/c64/multilines.c
index a9980f25..e49d3157 100644
--- a/presets/c64/multilines.c
+++ b/presets/c64/multilines.c
@@ -1,8 +1,3 @@
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <c64.h>
-#include <peekpoke.h>
 
 #include "common.h"
 //#link "common.c"
diff --git a/presets/c64/musicplayer.c b/presets/c64/musicplayer.c
index 267a63dd..90d0740f 100644
--- a/presets/c64/musicplayer.c
+++ b/presets/c64/musicplayer.c
@@ -3,10 +3,6 @@
 A simple music player.
 */
 
-#include <string.h>
-#include <c64.h>
-#include <_sid.h>
-
 #include "common.h"
 //#link "common.c"
 
diff --git a/presets/c64/scroll1.c b/presets/c64/scroll1.c
index 7541250f..ac704802 100644
--- a/presets/c64/scroll1.c
+++ b/presets/c64/scroll1.c
@@ -1,17 +1,6 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-
-typedef unsigned char byte;
-typedef unsigned short word;
-
-void rasterWait(unsigned char line) {
-  while (VIC.rasterline < line) ;
-}
+#include "common.h"
+//#link "common.c"
 
 byte x = 0;	// x scroll position
 byte y = 0;	// y scroll position
@@ -39,7 +28,7 @@ void main(void) {
     VIC.ctrl2 = VIC.ctrl2 & 0xf8;
     VIC.ctrl2 |= (x & 7);
     // wait for vsync
-    rasterWait(255);
+    waitvsync();
     // every 8 pixels, move screen cells
     if ((x & 7) == 0) {
       memcpy(scrnbuf, scrnbuf+1, 40*8-1);
diff --git a/presets/c64/scroll2.c b/presets/c64/scroll2.c
index 0ba906da..95d90f70 100644
--- a/presets/c64/scroll2.c
+++ b/presets/c64/scroll2.c
@@ -1,17 +1,6 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-
-typedef unsigned char byte;
-typedef unsigned short word;
-
-void rasterWait(unsigned char line) {
-  while (VIC.rasterline < line) ;
-}
+#include "common.h"
+//#link "common.c"
 
 byte x = 0;	// x scroll position
 byte y = 0;	// y scroll position
@@ -49,7 +38,7 @@ void main(void) {
     src = scrnbuf[frame&1] + (x&7)*128;
     dst = scrnbuf[frame&1^1] + (x&7)*128;
     // wait for vsync
-    rasterWait(255);
+    waitvsync();
     // scroll hidden buffer
     memcpy(dst, src+1, 128);
     // every 8 pixels, switch farmes
diff --git a/presets/c64/scroll3.c b/presets/c64/scroll3.c
index dcbf6091..400b677e 100644
--- a/presets/c64/scroll3.c
+++ b/presets/c64/scroll3.c
@@ -1,27 +1,6 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <joystick.h>
-
-typedef uint8_t byte;
-typedef uint16_t word;
-typedef int8_t sbyte;
-
-#define COLS 40
-#define ROWS 25
-
-void raster_wait(unsigned char line) {
-  while (VIC.rasterline < line) ;
-}
-
-void wait_vblank() {
-  raster_wait(255); // TODO
-}
+#include "common.h"
+//#link "common.c"
 
 sbyte scroll_fine_x = 0;
 sbyte scroll_fine_y = 0;
@@ -129,7 +108,7 @@ void main(void) {
     if (JOY_RIGHT(joy)) scroll_horiz(1);
     if (JOY_DOWN(joy)) scroll_vert(1);
     // update regs
-    wait_vblank();
+    waitvsync();
     scroll_update_regs();
   }
 }
diff --git a/presets/c64/scroll4.c b/presets/c64/scroll4.c
index ca859611..d8dbc5e6 100644
--- a/presets/c64/scroll4.c
+++ b/presets/c64/scroll4.c
@@ -1,13 +1,4 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <joystick.h>
-
 #include "common.h"
 //#link "common.c"
 
@@ -92,7 +83,7 @@ void main(void) {
     sprite_draw(0, n++, 70, 192);
     sprite_draw(0, 172, 145, 192);
     // wait for vblank
-    wait_vblank();
+    waitvsync();
     // update scroll registers
     // and swap screens if we must
     scroll_update();
diff --git a/presets/c64/scroll5.c b/presets/c64/scroll5.c
index b9fab836..071aa0c5 100644
--- a/presets/c64/scroll5.c
+++ b/presets/c64/scroll5.c
@@ -1,13 +1,4 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <joystick.h>
-
 #include "common.h"
 //#link "common.c"
 
@@ -124,8 +115,8 @@ void main(void) {
     slowframe = swap_needed;
     // animate sprite in shadow sprite ram
     update_player();
-    // wait for vblank
-    wait_vblank();
+    // wait for end of frame
+    waitvsync();
     // then update sprite registers
     sprite_update(visbuf);
     // update scroll registers
diff --git a/presets/c64/siddemo.c b/presets/c64/siddemo.c
index afc86dee..8d98f20c 100644
--- a/presets/c64/siddemo.c
+++ b/presets/c64/siddemo.c
@@ -1,9 +1,6 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <joystick.h>
+#include "common.h"
+//#link "common.c"
 
 //#resource "c64-sid.cfg"
 #define CFGFILE c64-sid.cfg
diff --git a/presets/c64/siegegame.c b/presets/c64/siegegame.c
index 33c22de5..f0bd1e5c 100644
--- a/presets/c64/siegegame.c
+++ b/presets/c64/siegegame.c
@@ -3,33 +3,20 @@ Text-based version of a Blockade-style game.
 For more information, see "Making Arcade Games in C".
 */
 
-#include <stdlib.h>
-#include <string.h>
-#include <joystick.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <peekpoke.h>
-
-#define COLS 40
-#define ROWS 24
-
-typedef unsigned char byte;
-typedef signed char sbyte;
-typedef unsigned short word;
+#include "common.h"
 
 // BASL = text address of cursor position
 static byte** BASL = (byte**) 0xD1;
 
-byte getchar(byte x, byte y) {
+// get the character at a specfic x/y position
+byte readcharxy(byte x, byte y) {
   gotoxy(x,y);		// set cursor position
   return (*BASL)[x];	// lookup value @ cursor address
 }
 
 void delay(byte count) {
   while (count--) {
-    word i;
-    for (i=0; i<200; i++) ;
+    waitvsync();
   }
 }
 
@@ -115,7 +102,7 @@ void move_player(Player* p) {
   cputcxy(p->x, p->y, p->tail_attr);
   p->x += DIR_X[p->dir];
   p->y += DIR_Y[p->dir];
-  if ((getchar(p->x, p->y) & 0x7f) != ' ')
+  if ((readcharxy(p->x, p->y) & 0x7f) != ' ')
     p->collided = 1;
   draw_player(p);
 }
@@ -141,7 +128,8 @@ byte ai_try_dir(Player* p, dir_t dir, byte shift) {
   dir &= 3;
   x = p->x + (DIR_X[dir] << shift);
   y = p->y + (DIR_Y[dir] << shift);
-  if (x < COLS && y < ROWS && (getchar(x, y) & 0x7f) == ' ') {
+  if (x < COLS && y < ROWS 
+      && (readcharxy(x, y) & 0x7f) == ' ') {
     p->dir = dir;
     return 1;
   } else {
diff --git a/presets/c64/sprite_collision.c b/presets/c64/sprite_collision.c
index fe051da7..c456b88d 100644
--- a/presets/c64/sprite_collision.c
+++ b/presets/c64/sprite_collision.c
@@ -1,12 +1,4 @@
 
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-
 #include "common.h"
 //#link "common.c"
 
diff --git a/presets/c64/sprite_test.c b/presets/c64/sprite_test.c
index 85e6d54c..d07f2cd1 100644
--- a/presets/c64/sprite_test.c
+++ b/presets/c64/sprite_test.c
@@ -1,11 +1,5 @@
 
-#include <conio.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <peekpoke.h>
-#include <string.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
+#include "common.h"
 
 /*{w:24,h:21,bpp:1,brev:1,count:1}*/
 const char SPRITE_DATA[64] = {
diff --git a/presets/c64/spritesinborder.c b/presets/c64/spritesinborder.c
index 6c741168..ab7ce4a2 100644
--- a/presets/c64/spritesinborder.c
+++ b/presets/c64/spritesinborder.c
@@ -1,9 +1,4 @@
   
-#include <stdio.h>
-#include <conio.h>
-#include <c64.h>
-#include <cbm_petscii_charmap.h>
-
 //#link "common.c"
 #include "common.h"
 
@@ -13,6 +8,8 @@
 //#link "sprites.c"
 #include "sprites.h"
 
+#include <cbm_petscii_charmap.h>
+
 /*{w:24,h:21,bpp:1,brev:1}*/
 const char spriteshape[3*21] = {
   0x00,0x7F,0x00,0x01,0xFF,0xC0,0x03,0xFF,0xE0,
diff --git a/presets/c64/upandaway.c b/presets/c64/upandaway.c
index 21932336..cf6a9b9d 100644
--- a/presets/c64/upandaway.c
+++ b/presets/c64/upandaway.c
@@ -1,11 +1,7 @@
 // ported from
 // https://odensskjegg.home.blog/2018/12/29/recreating-the-commodore-64-user-guide-code-samples-in-cc65-part-three-sprites/
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <conio.h>
-#include <peekpoke.h>
-#include <c64.h>
+#include "common.h"
 
 /*{w:24,h:21,bpp:1,brev:1}*/
 const char sprite[3*21] = {