diff --git a/presets/c64/plasma.c b/presets/c64/plasma.c
new file mode 100644
index 00000000..f48d6dc7
--- /dev/null
+++ b/presets/c64/plasma.c
@@ -0,0 +1,300 @@
+/*****************************************************************************\
+** plasma test program for cc65.                                             **
+**                                                                           **
+** (w)2001 by groepaz                                                        **
+**                                                                           **
+** Cleanup and porting by Ullrich von Bassewitz.                             **
+**                                                                           **
+\*****************************************************************************/
+
+
+
+#include <stdlib.h>
+#include <time.h>
+#include <conio.h>
+#include <cc65.h>
+
+
+
+#if defined(__C64__) || defined(__C128__)
+#  define SCREEN1               0xE000
+#  define SCREEN2               0xE400
+#  define CHARSET               0xE800
+#  define outb(addr,val)        (*(addr)) = (val)
+#  define inb(addr)             (*(addr))
+#elif defined(__CBM510__)
+#  define SCREEN1               0xF000
+#  define SCREEN2               0xF400
+#  define CHARSET               0xE000
+#  define outb(addr,val)        pokebsys ((unsigned)(addr), val)
+#  define inb(addr)             peekbsys ((unsigned)(addr))
+#elif defined(__PLUS4__)
+#  define SCREEN1               0x6400
+#  define SCREEN2               0x6C00
+#  define CHARSET               0x7000
+#  define outb(addr,val)        (*(addr)) = (val)
+#  define inb(addr)             (*(addr))
+#endif
+
+
+
+/* Values for the VIC address register to switch between the two pages */
+#if defined(__PLUS4__)
+#define PAGE1                   ((SCREEN1 >> 8) & 0xF8)
+#define PAGE2                   ((SCREEN2 >> 8) & 0xF8)
+#define CHARADR                 ((CHARSET >> 8) & 0xFC)
+#else
+#define PAGE1                   ((SCREEN1 >> 6) & 0xF0) | ((CHARSET >> 10) & 0x0E)
+#define PAGE2                   ((SCREEN2 >> 6) & 0xF0) | ((CHARSET >> 10) & 0x0E)
+#endif
+
+
+
+/* Use static local variables for speed */
+#pragma static-locals (1);
+
+
+static const unsigned char sinustable[0x100] = {
+    0x80, 0x7d, 0x7a, 0x77, 0x74, 0x70, 0x6d, 0x6a,
+    0x67, 0x64, 0x61, 0x5e, 0x5b, 0x58, 0x55, 0x52,
+    0x4f, 0x4d, 0x4a, 0x47, 0x44, 0x41, 0x3f, 0x3c,
+    0x39, 0x37, 0x34, 0x32, 0x2f, 0x2d, 0x2b, 0x28,
+    0x26, 0x24, 0x22, 0x20, 0x1e, 0x1c, 0x1a, 0x18,
+    0x16, 0x15, 0x13, 0x11, 0x10, 0x0f, 0x0d, 0x0c,
+    0x0b, 0x0a, 0x08, 0x07, 0x06, 0x06, 0x05, 0x04,
+    0x03, 0x03, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01,
+    0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x03,
+    0x03, 0x04, 0x05, 0x06, 0x06, 0x07, 0x08, 0x0a,
+    0x0b, 0x0c, 0x0d, 0x0f, 0x10, 0x11, 0x13, 0x15,
+    0x16, 0x18, 0x1a, 0x1c, 0x1e, 0x20, 0x22, 0x24,
+    0x26, 0x28, 0x2b, 0x2d, 0x2f, 0x32, 0x34, 0x37,
+    0x39, 0x3c, 0x3f, 0x41, 0x44, 0x47, 0x4a, 0x4d,
+    0x4f, 0x52, 0x55, 0x58, 0x5b, 0x5e, 0x61, 0x64,
+    0x67, 0x6a, 0x6d, 0x70, 0x74, 0x77, 0x7a, 0x7d,
+    0x80, 0x83, 0x86, 0x89, 0x8c, 0x90, 0x93, 0x96,
+    0x99, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8, 0xab, 0xae,
+    0xb1, 0xb3, 0xb6, 0xb9, 0xbc, 0xbf, 0xc1, 0xc4,
+    0xc7, 0xc9, 0xcc, 0xce, 0xd1, 0xd3, 0xd5, 0xd8,
+    0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8,
+    0xea, 0xeb, 0xed, 0xef, 0xf0, 0xf1, 0xf3, 0xf4,
+    0xf5, 0xf6, 0xf8, 0xf9, 0xfa, 0xfa, 0xfb, 0xfc,
+    0xfd, 0xfd, 0xfe, 0xfe, 0xfe, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xfe, 0xfe, 0xfe, 0xfd,
+    0xfd, 0xfc, 0xfb, 0xfa, 0xfa, 0xf9, 0xf8, 0xf6,
+    0xf5, 0xf4, 0xf3, 0xf1, 0xf0, 0xef, 0xed, 0xeb,
+    0xea, 0xe8, 0xe6, 0xe4, 0xe2, 0xe0, 0xde, 0xdc,
+    0xda, 0xd8, 0xd5, 0xd3, 0xd1, 0xce, 0xcc, 0xc9,
+    0xc7, 0xc4, 0xc1, 0xbf, 0xbc, 0xb9, 0xb6, 0xb3,
+    0xb1, 0xae, 0xab, 0xa8, 0xa5, 0xa2, 0x9f, 0x9c,
+    0x99, 0x96, 0x93, 0x90, 0x8c, 0x89, 0x86, 0x83
+};
+
+
+
+static void doplasma (register unsigned char* scrn)
+{
+    unsigned char xbuf[40];
+    unsigned char ybuf[25];
+    unsigned char c1a,c1b;
+    unsigned char c2a,c2b;
+    unsigned char c1A,c1B;
+    unsigned char c2A,c2B;
+    register unsigned char i, ii;
+
+    c1a = c1A;
+    c1b = c1B;
+    for (ii = 0; ii < 25; ++ii) {
+        ybuf[ii] = (sinustable[c1a] + sinustable[c1b]);
+        c1a += 4;
+        c1b += 9;
+    }
+    c1A += 3;
+    c1B -= 5;
+    c2a = c2A;
+    c2b = c2B;
+    for (i = 0; i < 40; ++i) {
+        xbuf[i] = (sinustable[c2a] + sinustable[c2b]);
+        c2a += 3;
+        c2b += 7;
+    }
+    c2A += 2;
+    c2B -= 3;
+    for (ii = 0; ii < 25; ++ii) {
+        /* Unrolling the following loop will give a speed increase of
+        ** nearly 100% (~24fps), but it will also increase the code
+        ** size a lot.
+        */
+        for (i = 0; i < 40; ++i, ++scrn) {
+            *scrn = (xbuf[i] + ybuf[ii]);
+        }
+    }
+}
+
+static void makechar (void)
+{
+    static const unsigned char bittab[8] = {
+        0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
+    };
+    unsigned char i, ii, b, s;
+    unsigned c;
+
+    gotoxy (0, 1);
+    for (c = 0; c < 0x100; ++c) {
+        s = sinustable[c];
+        for (i = 0; i < 8; ++i){
+            b = 0;
+            for (ii = 0; ii < 8; ++ii) {
+                if ((rand() & 0xFFu) > s) {
+                    b |= bittab[ii];
+                }
+            }
+            ((unsigned char*)CHARSET) [(c*8) + i] = b;
+        }
+        if ((c & 0x07) == 0) {
+            cputc ('.');
+        }
+    }
+}
+
+
+
+int main (void)
+{
+    unsigned char border;
+    unsigned char background;
+    unsigned char text;
+    unsigned char v;
+    clock_t       t;
+    unsigned long f = 0;
+    unsigned long sec;
+    unsigned      sec10;
+    unsigned long fps;
+    unsigned      fps10;
+
+
+#if defined(__C64__)
+    unsigned char block;
+#endif
+#if defined(__C128__)
+    unsigned char block;
+    unsigned char initflag;
+    unsigned char graphflag;
+#endif
+#if defined(__PLUS4__)
+    unsigned int i;
+    unsigned char v2;
+#endif
+
+    clrscr ();
+    cprintf ("Making charset, mompls");
+    makechar();
+
+    /* Set the border and background colors */
+    border     = bordercolor (COLOR_BLUE);
+    background = bgcolor (COLOR_BLUE);
+    text       = textcolor (COLOR_BLACK);
+    clrscr ();
+
+#if defined(__C64__) || defined(__C128__)
+    /* Move the VIC 16K block */
+    block = inb (&CIA2.pra);
+    outb (&CIA2.pra, (block & 0xFC) | ((SCREEN1 >> 14) ^ 0x03));
+#endif
+#if defined(__C128__)
+    /* Save and change some flags, so that kernal/basic interrupt handler will
+    ** not interfere with our routine.
+    */
+    initflag = *(unsigned char*) 0xA04;
+    *(unsigned char*) 0xA04 &= 0xFE;
+    graphflag = *(unsigned char*) 0xD8;
+    *(unsigned char*) 0xD8 = 0xFF;
+#endif
+
+    /* Remember the VIC address register */
+#if defined(__PLUS4__)
+    v = inb (&TED.char_addr);
+    v2 = inb (&TED.video_addr);
+#else
+    v = inb (&VIC.addr);
+#endif
+
+#if defined(__PLUS4__)
+    for (i=0;i<1000;i++) {
+        ((unsigned char *) (SCREEN1-0x0400))[i] = 0;
+        ((unsigned char *) (SCREEN2-0x0400))[i] = 0;
+    }
+    outb (&TED.char_addr, CHARADR);
+#endif
+
+    /* Run the demo until a key was hit */
+    t = clock ();
+    while (!kbhit()) {
+        /* Build page 1, then make it visible */
+        doplasma ((unsigned char*)SCREEN1);
+#if defined(__PLUS4__)
+        outb (&TED.video_addr, PAGE1);
+#else
+        outb (&VIC.addr, PAGE1);
+#endif
+
+        /* Build page 2, then make it visible */
+        doplasma ((unsigned char*)SCREEN2);
+#if defined(__PLUS4__)
+        outb (&TED.video_addr, PAGE2);
+#else
+        outb (&VIC.addr, PAGE2);
+#endif
+
+        /* Count frames */
+        f += 2;
+    }
+    t = clock() - t;
+
+    /* Switch back the VIC screen */
+#if defined(__PLUS4__)
+    outb (&TED.video_addr, v2);
+    outb (&TED.char_addr, v);
+#else
+    outb (&VIC.addr, v);
+#endif
+
+#if defined(__C64__) || defined(__C128__)
+    /* Move back the VIC 16K block */
+    outb (&CIA2.pra, block);
+#endif
+#if defined(__C128__)
+    /* Restore the flags */
+    *(unsigned char*) 0xA04 = initflag;
+    *(unsigned char*) 0xD8  = graphflag;
+#endif
+
+    /* Fetch the character from the keyboard buffer and discard it */
+    (void) cgetc();
+
+    /* Reset screen colors */
+    bordercolor (border);
+    bgcolor (background);
+    textcolor (text);
+    clrscr ();
+
+    /* Calculate stats */
+    sec   = (t * 10) / CLK_TCK;
+    sec10 = sec % 10;
+    sec  /= 10;
+    fps   = (f * (CLK_TCK * 10)) / t;
+    fps10 = fps % 10;
+    fps  /= 10;
+
+    /* Output stats */
+    gotoxy (0, 0); cprintf ("time  : %lu.%us", sec, sec10);
+    gotoxy (0, 1); cprintf ("frames: %lu", f);
+    gotoxy (0, 2); cprintf ("fps   : %lu.%u", fps, fps10);
+
+    if (doesclrscrafterexit ()) {
+        cputsxy (0, 4, "Press any key when done...");
+        (void) cgetc ();
+    }
+
+    /* Done */
+    return EXIT_SUCCESS;
+}
diff --git a/presets/c64/side_scroller.c b/presets/c64/side_scroller.c
index a4e6ba4d..b2056a5c 100644
--- a/presets/c64/side_scroller.c
+++ b/presets/c64/side_scroller.c
@@ -124,6 +124,7 @@ void update_scoreboard() {
 
 void add_score(int delta) {
   score = bcd_add(score, delta);
+  update_scoreboard();
 }
 
 // clear scoreboard and draw initial strings
@@ -257,7 +258,6 @@ void detect_player_collision(byte bgcoll, byte sprcoll) {
     sprshad.spr_color[PLAYER_INDEX] = COLOR_LIGHTRED;
     SID_PLAY_TONE(500);
     if (score != 0) { add_score(0x9999); } // BCD -1
-    update_scoreboard();
   } else {
     sprshad.spr_color[PLAYER_INDEX] = COLOR_GREEN;
   }
@@ -266,7 +266,6 @@ void detect_player_collision(byte bgcoll, byte sprcoll) {
     sprshad.spr_color[POWERUP_INDEX] += 1; // cycle colors
     SID_PLAY_TONE(8000);
     add_score(1);
-    update_scoreboard();
   }
 }
 
diff --git a/presets/c64/test_display_list.c b/presets/c64/test_display_list.c
new file mode 100644
index 00000000..3f582fe6
--- /dev/null
+++ b/presets/c64/test_display_list.c
@@ -0,0 +1,143 @@
+
+#include "common.h"
+//#link "common.c"
+
+#include "rasterirq.h"
+//#link "rasterirq.ca65"
+
+#include "bcd.h"
+//#link "bcd.c"
+
+///// DEFINES
+
+#define GAME_BASE 0x400		// scrolling screen ram
+#define SCORE_BASE 0x2c00	// scoreboard screen ram
+
+#define SCROLL_TOP 8		// scroll top row
+#define SCROLL_ROWS 14		// scroll # of rows
+#define GROUND_ROW 7		// ground row (+ top row)
+
+///// VARIABLES
+
+word scroll_x = 0;	 // current scroll X position
+word score = 0;		 // current player score
+
+///// FUNCTIONS
+
+// display list used by rasterirq.h
+// draws scoreboard and sets scroll register
+void display_list() {
+  // set x scroll register to scroll value
+  SET_SCROLL_X(scroll_x);
+  // set background color
+  VIC.bgcolor[0] = COLOR_CYAN;
+  // next interrupt is two rows from bottom
+  DLIST_NEXT(250-16);
+
+  // set background color
+  VIC.bgcolor[0] = COLOR_BLUE;
+  // screen memory = 0x2800
+  SET_VIC_SCREEN(SCORE_BASE);
+  // clear x scroll register
+  SET_SCROLL_X(0);
+  // next interrupt is bottom of frame
+  DLIST_NEXT(250);
+
+  // reset screen to 0x400
+  SET_VIC_SCREEN(0x400);
+  // next interrupt is above top of next frame
+  DLIST_RESTART(40);
+}
+
+void update_scoreboard() {
+  draw_bcd_word(SCRNADR(SCORE_BASE,7,24), score);
+}
+
+void add_score(int delta) {
+  score = bcd_add(score, delta);
+}
+
+// clear scoreboard and draw initial strings
+void init_scoreboard() {
+  memset((void*)SCORE_BASE, ' ', 1024);
+  memcpy((void*)SCRNADR(SCORE_BASE,1,24), "SCORE:", 6);
+  update_scoreboard();
+}
+
+byte get_char_for_row(byte row) {
+  // ground?
+  if (row >= GROUND_ROW) { return 253; }
+  // obstacle?
+  if (row >= GROUND_ROW-3) {
+    // only show obstacle for certain values of scroll_x
+    if ((scroll_x & 0b1110000) == 0) { return 247; }
+  }
+  // default is the sky (empty space)
+  return 32;
+}
+
+void draw_right_column() {
+  // get the top-right corner address of scroll area
+  word addr = SCRNADR(GAME_BASE, 39, SCROLL_TOP);
+  byte row;
+  // draw one character per row
+  for (row=0; row<SCROLL_ROWS; row++) {
+    POKE(addr, get_char_for_row(row));
+    addr += 40;
+  }
+}
+
+void scroll_one_column_left() {
+  // copy several rows of screen memory
+  // backwards one byte
+  const word start = SCRNADR(GAME_BASE, 0, SCROLL_TOP);
+  const word nbytes = SCROLL_ROWS*40-1;
+  memcpy((byte*)start, (byte*)start+1, nbytes);
+  // draw the right column of characters
+  draw_right_column();
+}
+
+void scroll_one_pixel_left() {
+  // scroll left one pixel
+  scroll_x -= 1;
+  // set scroll register with lower three bits
+  VIC.ctrl2 = (VIC.ctrl2 & ~7) | (scroll_x & 7);
+  // move screen memory if the scroll register
+  // has just gone past 0 and wrapped to 7
+  if ((scroll_x & 7) == 7) {
+    scroll_one_column_left();
+  }
+}
+
+void main() {  
+  // clear screen, set background color
+  clrscr();
+  VIC.bgcolor[0] = COLOR_CYAN;
+  VIC.bordercolor = COLOR_BLUE;
+  
+  // set vertical scroll = 3, 25 rows
+  VIC.ctrl1 = 0b00011011;
+  // set 38 column mode (for X scrolling)
+  VIC.ctrl2 = 0b00000000;
+  // set uniform color of characters
+  memset(COLOR_RAM, COLOR_WHITE, 1000);
+
+  // setup scoreboard
+  init_scoreboard();
+
+  // setup rasterirq library for scoreboard split
+  DLIST_SETUP(display_list);
+  
+  // game loop, repeat forever
+  while (1) {    
+    // wait for end of frame
+    waitvsync();
+    
+    // scroll screen
+    scroll_one_pixel_left();
+    
+    // add to score
+    add_score(0x0001);
+    update_scoreboard();
+  }
+}
diff --git a/src/platform/c64.ts b/src/platform/c64.ts
index 65847938..b135dd1d 100644
--- a/src/platform/c64.ts
+++ b/src/platform/c64.ts
@@ -8,6 +8,7 @@ const C64_PRESETS = [
   {id:'hello.dasm', name:'Hello World (ASM)'},
   {id:'23matches.c', name:'23 Matches'},
   {id:'tgidemo.c', name:'TGI Graphics Demo'},
+  {id:'plasma.c', name:'Plasma Demo'},
   {id:'upandaway.c', name:'Up, Up and Away'},
   {id:'siegegame.c', name:'Siege Game'},
   {id:'joymove.c', name:'Sprite Movement'},
@@ -17,6 +18,7 @@ const C64_PRESETS = [
   {id:'scroll3.c', name:'Scrolling (Multidirectional)'},
   {id:'scroll4.c', name:'Scrolling (Color RAM Buffering)'},
   {id:'scroll5.c', name:'Scrolling (Camera Following)'},
+  {id:'test_display_list.c', name:'Display List / Raster IRQ'},
   {id:'side_scroller.c', name:'Side-Scrolling Game'},
   {id:'fullscrollgame.c', name:'Full-Scrolling Game'},
   {id:'test_multiplex.c', name:'Sprite Retriggering'},