diff --git a/presets/mw8080bw/game2.c b/presets/mw8080bw/game2.c
index 99bb9a68..840df318 100644
--- a/presets/mw8080bw/game2.c
+++ b/presets/mw8080bw/game2.c
@@ -88,9 +88,6 @@ const byte font8x8[HICHAR-LOCHAR+1][8] = {
 { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x79,0x79,0x00,0x00,0x00 }, { 0x00,0x70,0x70,0x00,0x00,0x70,0x70,0x00 }, { 0x14,0x7f,0x7f,0x14,0x14,0x7f,0x7f,0x14 }, { 0x00,0x12,0x3a,0x6b,0x6b,0x2e,0x24,0x00 }, { 0x00,0x63,0x66,0x0c,0x18,0x33,0x63,0x00 }, { 0x00,0x26,0x7f,0x59,0x59,0x77,0x27,0x05 }, { 0x00,0x00,0x00,0x10,0x30,0x60,0x40,0x00 }, { 0x00,0x00,0x1c,0x3e,0x63,0x41,0x00,0x00 }, { 0x00,0x00,0x41,0x63,0x3e,0x1c,0x00,0x00 }, { 0x08,0x2a,0x3e,0x1c,0x1c,0x3e,0x2a,0x08 }, { 0x00,0x08,0x08,0x3e,0x3e,0x08,0x08,0x00 }, { 0x00,0x00,0x00,0x03,0x03,0x00,0x00,0x00 }, { 0x00,0x08,0x08,0x08,0x08,0x08,0x08,0x00 }, { 0x00,0x00,0x00,0x03,0x03,0x00,0x00,0x00 }, { 0x00,0x01,0x03,0x06,0x0c,0x18,0x30,0x20 }, { 0x00,0x3e,0x7f,0x49,0x51,0x7f,0x3e,0x00 }, { 0x00,0x01,0x11,0x7f,0x7f,0x01,0x01,0x00 }, { 0x00,0x23,0x67,0x45,0x49,0x79,0x31,0x00 }, { 0x00,0x22,0x63,0x49,0x49,0x7f,0x36,0x00 }, { 0x00,0x0c,0x0c,0x14,0x34,0x7f,0x7f,0x04 }, { 0x00,0x72,0x73,0x51,0x51,0x5f,0x4e,0x00 }, { 0x00,0x3e,0x7f,0x49,0x49,0x6f,0x26,0x00 }, { 0x00,0x60,0x60,0x4f,0x5f,0x70,0x60,0x00 }, { 0x00,0x36,0x7f,0x49,0x49,0x7f,0x36,0x00 }, { 0x00,0x32,0x7b,0x49,0x49,0x7f,0x3e,0x00 }, { 0x00,0x00,0x00,0x12,0x12,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x13,0x13,0x00,0x00,0x00 }, { 0x00,0x08,0x1c,0x36,0x63,0x41,0x41,0x00 }, { 0x00,0x14,0x14,0x14,0x14,0x14,0x14,0x00 }, { 0x00,0x41,0x41,0x63,0x36,0x1c,0x08,0x00 }, { 0x00,0x20,0x60,0x45,0x4d,0x78,0x30,0x00 }, { 0x00,0x3e,0x7f,0x41,0x59,0x79,0x3a,0x00 }, { 0x00,0x1f,0x3f,0x68,0x68,0x3f,0x1f,0x00 }, { 0x00,0x7f,0x7f,0x49,0x49,0x7f,0x36,0x00 }, { 0x00,0x3e,0x7f,0x41,0x41,0x63,0x22,0x00 }, { 0x00,0x7f,0x7f,0x41,0x63,0x3e,0x1c,0x00 }, { 0x00,0x7f,0x7f,0x49,0x49,0x41,0x41,0x00 }, { 0x00,0x7f,0x7f,0x48,0x48,0x40,0x40,0x00 }, { 0x00,0x3e,0x7f,0x41,0x49,0x6f,0x2e,0x00 }, { 0x00,0x7f,0x7f,0x08,0x08,0x7f,0x7f,0x00 }, { 0x00,0x00,0x41,0x7f,0x7f,0x41,0x00,0x00 }, { 0x00,0x02,0x03,0x41,0x7f,0x7e,0x40,0x00 }, { 0x00,0x7f,0x7f,0x1c,0x36,0x63,0x41,0x00 }, { 0x00,0x7f,0x7f,0x01,0x01,0x01,0x01,0x00 }, { 0x00,0x7f,0x7f,0x30,0x18,0x30,0x7f,0x7f }, { 0x00,0x7f,0x7f,0x38,0x1c,0x7f,0x7f,0x00 }, { 0x00,0x3e,0x7f,0x41,0x41,0x7f,0x3e,0x00 }, { 0x00,0x7f,0x7f,0x48,0x48,0x78,0x30,0x00 }, { 0x00,0x3c,0x7e,0x42,0x43,0x7f,0x3d,0x00 }, { 0x00,0x7f,0x7f,0x4c,0x4e,0x7b,0x31,0x00 }, { 0x00,0x32,0x7b,0x49,0x49,0x6f,0x26,0x00 }, { 0x00,0x40,0x40,0x7f,0x7f,0x40,0x40,0x00 }, { 0x00,0x7e,0x7f,0x01,0x01,0x7f,0x7e,0x00 }, { 0x00,0x7c,0x7e,0x03,0x03,0x7e,0x7c,0x00 }, { 0x00,0x7f,0x7f,0x06,0x0c,0x06,0x7f,0x7f }, { 0x00,0x63,0x77,0x1c,0x1c,0x77,0x63,0x00 }, { 0x00,0x70,0x78,0x0f,0x0f,0x78,0x70,0x00 }, { 0x00,0x43,0x47,0x4d,0x59,0x71,0x61,0x00 }, { 0x00,0x00,0x7f,0x7f,0x41,0x41,0x00,0x00 }, { 0x00,0x20,0x30,0x18,0x0c,0x06,0x03,0x01 }, { 0x00,0x00,0x41,0x41,0x7f,0x7f,0x00,0x00 }, { 0x00,0x08,0x18,0x3f,0x3f,0x18,0x08,0x00 }
 };
 
-const byte bitmap1[] =
-{6,63,0x00,0x00,0x00,0x00,0x18,0x00,0x00,0x00,0x00,0x00,0x7e,0x00,0x00,0x00,0x00,0x80,0x63,0x00,0x00,0x00,0x00,0xc0,0xc0,0x00,0x00,0x00,0x00,0x5e,0x80,0x00,0x00,0x00,0x00,0x73,0x80,0x00,0x00,0x00,0x00,0xe3,0x83,0x00,0x00,0x00,0x00,0xe3,0x9f,0x00,0x00,0x00,0x00,0xc2,0xbf,0x00,0x00,0x00,0xc0,0x03,0xff,0x00,0x00,0x00,0x70,0x06,0xfe,0x01,0x00,0x00,0x18,0x0c,0x00,0x03,0x00,0x00,0x0c,0x18,0x00,0x02,0x00,0x00,0x02,0x30,0x00,0x02,0x00,0x00,0x0f,0xe0,0x00,0x03,0x00,0xc0,0x10,0x80,0xef,0x01,0x00,0x40,0x27,0x00,0x38,0x00,0x00,0xa0,0x47,0x00,0x60,0x00,0x00,0xe0,0x4f,0xf8,0x60,0x00,0x00,0xe0,0x4f,0x0c,0xe1,0x00,0x00,0xe0,0x4f,0x06,0xe2,0x01,0x00,0xe0,0x4f,0xf2,0xe2,0x03,0xfc,0xe0,0x4f,0xfb,0xe4,0x03,0xfe,0xff,0x4f,0xf9,0xe4,0x0f,0xff,0x87,0x27,0xf9,0xe5,0x0f,0xff,0x07,0x36,0xf9,0xe5,0x1f,0xff,0x07,0x18,0xf9,0xe4,0x3f,0xff,0x07,0x00,0xfa,0xe4,0x7f,0xfe,0x07,0x00,0x72,0xe2,0x7f,0xfc,0x03,0x00,0x06,0xe2,0x7f,0xdc,0x00,0x02,0xb8,0xe1,0xff,0x08,0x00,0x04,0x60,0xe0,0xff,0x30,0x00,0x1c,0x00,0xe0,0xff,0x60,0x80,0x03,0x00,0xc0,0x7f,0xc0,0xff,0x01,0x00,0x80,0x7f,0x00,0x00,0x01,0x00,0x80,0x3f,0x00,0x00,0x01,0x00,0x00,0x0e,0x00,0x00,0x01,0x00,0x00,0x02,0x00,0x00,0x01,0x00,0x00,0x02,0x00,0x00,0x01,0x00,0x00,0x02,0x00,0x80,0x01,0x00,0x01,0x02,0x00,0x80,0x00,0x00,0x09,0x02,0x00,0xc0,0x00,0x00,0x09,0x02,0x00,0xc0,0x00,0x00,0x09,0x02,0x00,0xc0,0x00,0x00,0x09,0x02,0x00,0xc0,0x00,0x80,0x08,0x02,0x00,0xc0,0x00,0x80,0x04,0x03,0x00,0xa0,0x00,0x80,0x04,0x03,0x00,0xa0,0x01,0x40,0x04,0x01,0x00,0x20,0x02,0x70,0x82,0x01,0x00,0x70,0xf4,0x1f,0x83,0x00,0x00,0x98,0x1d,0xf8,0xc0,0x00,0x00,0x88,0x0f,0x00,0x60,0x00,0x00,0x88,0x08,0x07,0x38,0x00,0x80,0x8f,0x08,0x3f,0x0e,0x00,0x80,0x98,0x08,0xe1,0x03,0x00,0x80,0x80,0x07,0x01,0x00,0x00,0x80,0xc1,0x0c,0x01,0x00,0x00,0x00,0x83,0x90,0x01,0x00,0x00,0x00,0xfe,0x81,0x00,0x00,0x00,0x00,0x00,0x86,0x00,0x00,0x00,0x00,0x00,0xd8,0x00,0x00,0x00,0x00,0x00,0x60,0x00,0x00,0x00}
-;
 const byte player_bitmap[] =
 {2,27,0,0,0,0,0x0f,0x00,0x3e,0x00,0xf4,0x07,0xec,0x00,0x76,0x00,0x2b,0x00,0x33,0x00,0x75,0x00,0xf5,0x00,0xeb,0x31,0xbf,0xef,0x3f,0xcf,0xbf,0xef,0xeb,0x31,0xf5,0x00,0x75,0x00,0x33,0x00,0x2b,0x00,0x76,0x00,0xec,0x00,0xf4,0x07,0x3e,0x00,0x0f,0x00,0x00,0x00,0,0}
 ;
@@ -101,8 +98,20 @@ const byte bullet_bitmap[] =
 {2,2,0x88,0x88,0x44,0x44}
 ;
 const byte enemy1_bitmap[] =
-{2,24,0x0f,0x00,0x3e,0x00,0xf4,0x07,0xec,0x00,0x76,0x00,0x2b,0x00,0x33,0x00,0x75,0x00,0xf5,0x00,0xeb,0x31,0xbf,0xef,0x3f,0xcf,0xbf,0xef,0xeb,0x31,0xf5,0x00,0x75,0x00,0x33,0x00,0x2b,0x00,0x76,0x00,0xec,0x00,0xf4,0x07,0x3e,0x00,0x0f,0x00,0x00,0x00,0,0}
-;
+{2,17,0x00,0x00,0x00,0x0c,0x04,0x1e,0x46,0x3f,0xb8,0x7f,0xb0,0x7f,0xba,0x7f,0xfd,0x3f,0xfc,0x07,0xfc,0x07,0xfd,0x3f,0xba,0x7f,0xb0,0x7f,0xb8,0x7f,0x46,0x3f,0x04,0x1e,0x00,0x0c};
+const byte enemy2_bitmap[] =
+{2,16,0x26,0x00,0x59,0x10,0x10,0x30,0x33,0x18,0xe6,0x61,0xc4,0x56,0x03,0x03,0xdc,0x03,0xdc,0x03,0x03,0x03,0xc4,0x56,0xe6,0x61,0x33,0x18,0x10,0x30,0x59,0x10,0x26,0x00};
+const byte enemy3_bitmap[] =
+{2,16,0x80,0x1f,0xc0,0x03,0xf8,0x3f,0x70,0x00,0xf0,0x01,0xfc,0x07,0xe8,0x01,0xf8,0x03,0xf8,0x03,0xe8,0x01,0xf8,0x07,0xf0,0x01,0x70,0x00,0xf8,0x3f,0xc0,0x03,0x80,0x1f};
+const byte enemy4_bitmap[] =
+{2,16,0x06,0x00,0x0c,0x00,0x28,0x00,0x70,0x1f,0x84,0x3f,0xde,0x37,0xbb,0x3f,0xf0,0x3f,0xf0,0x3f,0xbb,0x3f,0xde,0x37,0x84,0x3f,0x70,0x1f,0x28,0x00,0x0c,0x00,0x06,0x00};
+
+const byte* const enemy_bitmaps[4] = {
+  enemy1_bitmap,
+  enemy2_bitmap,
+  enemy3_bitmap,
+  enemy4_bitmap
+};
 
 void draw_sprite(const byte* src, byte x, byte y) {
   byte i,j;
@@ -188,18 +197,20 @@ typedef struct {
 MarchMode this_mode, next_mode;
 
 void init_entities() {
-  int i,x,y;
+  byte i,x,y,bm;
   x=0;
   y=26;
+  bm=0;
   for (i=0; i<MAX_ENTITIES; i++) {
     Entity* e = &entities[i];
     e->x = x;
     e->y = y;
-    e->shape = enemy1_bitmap;
+    e->shape = enemy_bitmaps[bm];
     x += 28;
     if (x > 180) {
       x = 0;
       y -= 3;
+      bm++;
     }
   }
   num_entities = MAX_ENTITIES;
@@ -284,9 +295,7 @@ void gameloop() {
   watchdog_strobe = 0b0111 / 14;
   draw_bunker(30, 40, 15, 15, 20);
   draw_bunker(120, 40, 15, 15, 20);
-  draw_sprite(enemy1_bitmap, 10, 20);
   init_entities();
-  //draw_sprite(bitmap1, 0, 0);
   player_x = 96;
   while (1) {
     if (LEFT1 && player_x>0) player_x -= 2;
diff --git a/presets/sound_williams-z80/swave.c b/presets/sound_williams-z80/swave.c
new file mode 100644
index 00000000..08872c17
--- /dev/null
+++ b/presets/sound_williams-z80/swave.c
@@ -0,0 +1,86 @@
+
+#include <string.h>
+
+typedef unsigned char byte;
+typedef unsigned short word;
+typedef signed char sbyte;
+
+const __sfr __at (0x0) command;
+__sfr __at (0x0) dac;
+
+#define HALT __asm halt __endasm;
+
+// press "2" or higher to activate...
+
+typedef struct {
+  word duration;
+  word offset;
+  word delta;
+  int deltainc;
+  byte wavetable;
+  signed char lfo;
+} SoundEffect;
+
+const char WAVES[] = {
+  -64,-64,-64,-64,-64,-64,-64,
+  -64,-64,-64,-64,-64,-64,-64,
+  64,64,64,64,64,64,64,64,
+  64,64,64,64,64,64,64,64,
+  
+  -64,64,-64,64,-64,64,-64,64,
+  -64,64,-64,64,-64,64,-64,64,
+  -64,64,-64,64,-64,64,-64,64,
+  -64,64,-64,64,-64,64,-64,64,
+  
+  -0x80,-0x78,-0x70,-0x68, -0x60,-0x58,-0x50,-0x48,
+  -0x40,-0x38,-0x30,-0x28, -0x20,-0x18,-0x10,-0x08,
+  0x00,0x08,0x10,0x18, 0x20,0x28,0x30,0x38,
+  0x40,0x48,0x50,0x58, 0x60,0x68,0x70,0x78,
+  
+0x60,0x37,0x3f,0x5c,0x16,0xca,0xc2,0xa5,0xfe,0xba,0x77,0x89,0xaa,0x77,0x13,0xd8,
+0xae,0x82,0xfd,0x22,0x9c,0x46,0xde,0x14,0x50,0xb4,0x97,0x46,0x54,0x9d,0x60,0x2b,
+};
+
+const sbyte* wav;
+SoundEffect e;
+
+const SoundEffect DEFAULT_SOUND = {
+  2000, 0, 3000, -1, 0x40, 0
+};
+
+void play();
+
+void main() {
+  if (command == 0) HALT;
+  memcpy(&e, &DEFAULT_SOUND, sizeof(e));
+  play();
+  /*
+  char i;
+  char j;
+  for (i=0; i<255; i++) {
+    for (j=0; j<i; j++) dac=j^i;
+  }
+  */
+  HALT;
+}
+
+void sample() {
+  dac = wav[(e.offset >> 11) & 0x1f];
+  e.offset += e.delta;
+}
+
+void play() {
+  wav = &WAVES[e.wavetable];
+  while (e.duration--) {
+    sample();
+    sample();
+    sample();
+    sample();
+    sample();
+    sample();
+    sample();
+    sample();
+    e.delta += e.deltainc;
+    e.deltainc += e.lfo;
+  }
+}
diff --git a/presets/williams-z80/sprites.c b/presets/williams-z80/sprites.c
index cc285711..d4c305bc 100644
--- a/presets/williams-z80/sprites.c
+++ b/presets/williams-z80/sprites.c
@@ -5,11 +5,11 @@ typedef unsigned char byte;
 typedef unsigned short word;
 
 byte __at (0xc000) palette[16];
-volatile byte __at (0xc800) input0;
-volatile byte __at (0xc802) input1;
-volatile byte __at (0xc804) input2;
+byte __at (0xc800) input0;
+byte __at (0xc802) input1;
+byte __at (0xc804) input2;
 byte __at (0xc900) rom_select;
-volatile byte __at (0xcb00) video_counter;
+byte __at (0xcb00) video_counter;
 byte __at (0xcbff) watchdog0x39;
 byte __at (0xcc00) nvram[0x400];
 
@@ -42,15 +42,53 @@ void start() {
 __asm
         LD      SP,#0xc000
         DI
+; copy initialized data
+        LD    BC, #l__INITIALIZER
+        LD    A, B
+        LD    DE, #s__INITIALIZED
+        LD    HL, #s__INITIALIZER
+        LDIR
 __endasm;
         main();
 }
 
-const byte palette_data[16] = {
-  0x00, 0x03, 0x19, 0x50, 0x52, 0x07, 0x1f, 0x37, 0xe0, 0xa4, 0xfd, 0xff, 0x00, 0x00, 0x00, 0x00, };
+#define LOCHAR 0x21
+#define HICHAR 0x5e
 
-const byte sprite_data[] = {
-8,128,
+const byte font8x8[HICHAR-LOCHAR+1][8] = {
+{ 0x18,0x18,0x18,0x18,0x00,0x00,0x18,0x00 }, { 0x66,0x66,0x66,0x00,0x00,0x00,0x00,0x00 }, { 0x66,0x66,0xff,0x66,0xff,0x66,0x66,0x00 }, { 0x18,0x3e,0x60,0x3c,0x06,0x7c,0x18,0x00 }, { 0x62,0x66,0x0c,0x18,0x30,0x66,0x46,0x00 }, { 0x3c,0x66,0x3c,0x38,0x67,0x66,0x3f,0x00 }, { 0x06,0x0c,0x18,0x00,0x00,0x00,0x00,0x00 }, { 0x0c,0x18,0x30,0x30,0x30,0x18,0x0c,0x00 }, { 0x30,0x18,0x0c,0x0c,0x0c,0x18,0x30,0x00 }, { 0x00,0x66,0x3c,0xff,0x3c,0x66,0x00,0x00 }, { 0x00,0x18,0x18,0x7e,0x18,0x18,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x30 }, { 0x00,0x00,0x00,0x7e,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00 }, { 0x00,0x03,0x06,0x0c,0x18,0x30,0x60,0x00 }, { 0x3c,0x66,0x6e,0x76,0x66,0x66,0x3c,0x00 }, { 0x18,0x18,0x38,0x18,0x18,0x18,0x7e,0x00 }, { 0x3c,0x66,0x06,0x0c,0x30,0x60,0x7e,0x00 }, { 0x3c,0x66,0x06,0x1c,0x06,0x66,0x3c,0x00 }, { 0x06,0x0e,0x1e,0x66,0x7f,0x06,0x06,0x00 }, { 0x7e,0x60,0x7c,0x06,0x06,0x66,0x3c,0x00 }, { 0x3c,0x66,0x60,0x7c,0x66,0x66,0x3c,0x00 }, { 0x7e,0x66,0x0c,0x18,0x18,0x18,0x18,0x00 }, { 0x3c,0x66,0x66,0x3c,0x66,0x66,0x3c,0x00 }, { 0x3c,0x66,0x66,0x3e,0x06,0x66,0x3c,0x00 }, { 0x00,0x00,0x18,0x00,0x00,0x18,0x00,0x00 }, { 0x00,0x00,0x18,0x00,0x00,0x18,0x18,0x30 }, { 0x0e,0x18,0x30,0x60,0x30,0x18,0x0e,0x00 }, { 0x00,0x00,0x7e,0x00,0x7e,0x00,0x00,0x00 }, { 0x70,0x18,0x0c,0x06,0x0c,0x18,0x70,0x00 }, { 0x3c,0x66,0x06,0x0c,0x18,0x00,0x18,0x00 }, { 0x3c,0x66,0x6e,0x6e,0x60,0x62,0x3c,0x00 }, { 0x18,0x3c,0x66,0x7e,0x66,0x66,0x66,0x00 }, { 0x7c,0x66,0x66,0x7c,0x66,0x66,0x7c,0x00 }, { 0x3c,0x66,0x60,0x60,0x60,0x66,0x3c,0x00 }, { 0x78,0x6c,0x66,0x66,0x66,0x6c,0x78,0x00 }, { 0x7e,0x60,0x60,0x78,0x60,0x60,0x7e,0x00 }, { 0x7e,0x60,0x60,0x78,0x60,0x60,0x60,0x00 }, { 0x3c,0x66,0x60,0x6e,0x66,0x66,0x3c,0x00 }, { 0x66,0x66,0x66,0x7e,0x66,0x66,0x66,0x00 }, { 0x3c,0x18,0x18,0x18,0x18,0x18,0x3c,0x00 }, { 0x1e,0x0c,0x0c,0x0c,0x0c,0x6c,0x38,0x00 }, { 0x66,0x6c,0x78,0x70,0x78,0x6c,0x66,0x00 }, { 0x60,0x60,0x60,0x60,0x60,0x60,0x7e,0x00 }, { 0x63,0x77,0x7f,0x6b,0x63,0x63,0x63,0x00 }, { 0x66,0x76,0x7e,0x7e,0x6e,0x66,0x66,0x00 }, { 0x3c,0x66,0x66,0x66,0x66,0x66,0x3c,0x00 }, { 0x7c,0x66,0x66,0x7c,0x60,0x60,0x60,0x00 }, { 0x3c,0x66,0x66,0x66,0x66,0x3c,0x0e,0x00 }, { 0x7c,0x66,0x66,0x7c,0x78,0x6c,0x66,0x00 }, { 0x3c,0x66,0x60,0x3c,0x06,0x66,0x3c,0x00 }, { 0x7e,0x18,0x18,0x18,0x18,0x18,0x18,0x00 }, { 0x66,0x66,0x66,0x66,0x66,0x66,0x3c,0x00 }, { 0x66,0x66,0x66,0x66,0x66,0x3c,0x18,0x00 }, { 0x63,0x63,0x63,0x6b,0x7f,0x77,0x63,0x00 }, { 0x66,0x66,0x3c,0x18,0x3c,0x66,0x66,0x00 }, { 0x66,0x66,0x66,0x3c,0x18,0x18,0x18,0x00 }, { 0x7e,0x06,0x0c,0x18,0x30,0x60,0x7e,0x00 }, { 0x3c,0x30,0x30,0x30,0x30,0x30,0x3c,0x00 }, { 0x00,0x60,0x30,0x18,0x0c,0x06,0x03,0x00 }, { 0x3c,0x0c,0x0c,0x0c,0x0c,0x0c,0x3c,0x00 }, { 0x00,0x18,0x3c,0x7e,0x18,0x18,0x18,0x18 }
+};
+
+static byte font_table[HICHAR-LOCHAR+1][8*4];
+
+void fill_char_table_entry(char ch) {
+  const byte* src = &font8x8[ch-LOCHAR][0];
+  byte* data = &font_table[ch-LOCHAR][0];
+  int i,j,pixels;
+  for (i=0; i<8; i++) {
+    byte b = *src++;
+    for (j=0; j<4; j++) {
+      pixels = 0;
+      if (b & 0x80) pixels |= 0xf0;
+      if (b & 0x40) pixels |= 0x0f;
+      *data++ = pixels;
+      b <<= 2;
+    }
+  }
+}
+
+void fill_char_table() {
+  char ch;
+  for (ch=LOCHAR; ch<=HICHAR; ch++) {
+    fill_char_table_entry(ch);
+  }
+}
+
+const byte palette_data[16] = {
+  0x00, 0x03, 0x19, 0x50, 0x52, 0x07, 0x1f, 0x37, 0xe0, 0xa4, 0xfd, 0xff, 0x00, 0x00, 0x00, 0xf8, };
+
+const byte sprite1[2+16*16/2] = {
+8,16,
 0x00,0x09,0x99,0x00,0x00,0x99,0x90,0x00,
 0x00,0x94,0x94,0x90,0x09,0x49,0x49,0x00,
 0x04,0x49,0x49,0x90,0x09,0x94,0x94,0x90,
@@ -66,7 +104,30 @@ const byte sprite_data[] = {
 0x03,0x30,0x00,0x33,0x33,0x00,0x03,0x30,
 0x00,0x30,0x03,0x00,0x00,0x30,0x03,0x00,
 0x00,0x00,0x00,0x30,0x03,0x00,0x00,0x00,
+0x00,0x09,0x99,0x00,0x00,0x99,0x90,0x00,
+};
+
+const byte sprite2[2+16*16/2] = {
+8,16,
+0x00,0x94,0x94,0x90,0x09,0x49,0x49,0x00,
+0x04,0x49,0x49,0x90,0x09,0x94,0x94,0x90,
+0x94,0x99,0x94,0x90,0x09,0x49,0x99,0x49,
+0x99,0x99,0x49,0x93,0x39,0x94,0x99,0x99,
+0x04,0x49,0x99,0x94,0x49,0x99,0x94,0x90,
+0x00,0x94,0x94,0x43,0x34,0x49,0x49,0x00,
+0x00,0x09,0x43,0x94,0x49,0x34,0x90,0x00,
+0x00,0x90,0x00,0x39,0x93,0x00,0x09,0x00,
+0x00,0x09,0x83,0x33,0x33,0x33,0x90,0x00,
+0x00,0x09,0x32,0x23,0x32,0x23,0x90,0x00,
+0x00,0x03,0x03,0x23,0x82,0x30,0x30,0x00,
+0x03,0x30,0x00,0x33,0x33,0x00,0x03,0x30,
+0x00,0x30,0x03,0x00,0x00,0x30,0x03,0x00,
+0x00,0x00,0x00,0x30,0x03,0x00,0x00,0x00,
 0x00,0x00,0x00,0x40,0x00,0x00,0x00,0x00,
+};
+
+const byte sprite3[2+16*16/2] = {
+8,16,
 0x00,0x00,0x00,0x01,0x10,0x00,0x00,0x00,
 0x00,0x00,0x00,0x11,0x11,0x00,0x00,0x00,
 0x00,0x00,0x00,0x01,0x10,0x00,0x00,0x00,
@@ -83,6 +144,10 @@ const byte sprite_data[] = {
 0x00,0x10,0x01,0x00,0x00,0x10,0x01,0x00,
 0x00,0x10,0x00,0x00,0x00,0x00,0x01,0x00,
 0x00,0x01,0x10,0x00,0x00,0x01,0x10,0x00,
+};
+
+const byte sprite4[2+16*16/2] = {
+8,16,
 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
 0x00,0x00,0x00,0xbb,0xbb,0x00,0x00,0x00,
 0x00,0x00,0x00,0xbb,0xbb,0x00,0x00,0x00,
@@ -99,6 +164,10 @@ const byte sprite_data[] = {
 0x01,0x00,0x01,0x51,0x15,0x10,0x00,0x10,
 0x00,0x10,0x01,0x10,0x01,0x10,0x01,0x00,
 0x01,0x01,0x10,0x10,0x01,0x01,0x10,0x10,
+};
+
+const byte sprite5[2+16*16/2] = {
+8,16,
 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
 0x00,0x00,0x22,0x00,0x00,0x22,0x00,0x00,
 0x00,0x20,0x20,0x00,0x00,0x02,0x02,0x00,
@@ -115,10 +184,10 @@ const byte sprite_data[] = {
 0x20,0x00,0x22,0x12,0x21,0x22,0x00,0x02,
 0x20,0x02,0x20,0x20,0x02,0x02,0x20,0x02,
 0x02,0x02,0x00,0x20,0x02,0x00,0x20,0x20,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const byte sprite6[2+12*16/2] = {
+8,12,
 0x00,0x00,0x00,0x00,0x04,0x04,0x04,0x00,
 0x00,0x00,0x00,0x00,0x44,0x44,0x44,0x40,
 0x00,0x00,0x04,0x04,0x49,0x49,0x99,0x44,
@@ -129,9 +198,10 @@ const byte sprite_data[] = {
 0x04,0x44,0x00,0x49,0x44,0x40,0x00,0x00,
 0x04,0x40,0x00,0x04,0x00,0x00,0x00,0x00,
 0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const byte sprite7[2+16*16/2] = {
+8,16,
 0x00,0x60,0x00,0x00,0x00,0x00,0x06,0x00,
 0x60,0x60,0x00,0x00,0x00,0x00,0x06,0x06,
 0x60,0x60,0x50,0x00,0x00,0x05,0x06,0x06,
@@ -146,8 +216,10 @@ const byte sprite_data[] = {
 0x00,0x10,0x01,0x01,0x10,0x10,0x01,0x00,
 0x00,0x10,0x11,0x00,0x00,0x11,0x01,0x00,
 0x00,0x00,0x10,0x00,0x00,0x01,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const byte sprite8[2+16*16/2] = {
+8,16,
 0x00,0x00,0x11,0x11,0x11,0x11,0x00,0x00,
 0x00,0x01,0x61,0x11,0x21,0x12,0x10,0x00,
 0x00,0x11,0x12,0x11,0x61,0x11,0x11,0x00,
@@ -163,7 +235,10 @@ const byte sprite_data[] = {
 0x88,0x00,0x88,0x00,0x00,0x88,0x00,0x88,
 0x80,0x00,0x08,0x80,0x08,0x80,0x00,0x08,
 0x00,0x00,0x00,0x80,0x08,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const byte sprite9[2+13*16/2] = {
+8,13,
 0x00,0x00,0xaa,0x00,0x00,0xaa,0x00,0x00,
 0x00,0x00,0xa0,0x0a,0xa0,0x0a,0x00,0x00,
 0x0a,0xaa,0xa4,0xaa,0xaa,0x3a,0xaa,0xa0,
@@ -177,8 +252,18 @@ const byte sprite_data[] = {
 0x00,0xa3,0xa0,0x00,0x00,0x0a,0x4a,0x00,
 0x00,0xaa,0xa0,0x00,0x00,0x0a,0xaa,0x00,
 0x00,0x0a,0xa0,0x00,0x00,0x0a,0xa0,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
-0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const byte* const all_sprites[9] = {
+  sprite1,
+  sprite2,
+  sprite3,
+  sprite4,
+  sprite5,
+  sprite6,
+  sprite7,
+  sprite8,
+  sprite9,
 };
 
 inline word swapw(word j) {
@@ -200,7 +285,6 @@ inline void blit_copy(byte x1, byte y1, byte w, byte h, const byte* data) {
   blitter.height = h^4;
   blitter.sstart = swapw((word)data);
   blitter.dstart = x1+y1*256; // swapped
-  blitter.solid = 0;
   blitter.flags = DSTSCREEN|FGONLY;
 }
 
@@ -218,24 +302,164 @@ inline void draw_sprite(const byte* data, byte x, byte y) {
   blitter.height = data[1]^4;
   blitter.sstart = swapw((word)(data+2));
   blitter.dstart = x+y*256; // swapped
-  blitter.solid = 0;
   blitter.flags = DSTSCREEN|FGONLY;
 }
 
+inline void draw_sprite_solid(const byte* data, byte x, byte y, byte color) {
+  blitter.width = data[0]^4;
+  blitter.height = data[1]^4;
+  blitter.sstart = swapw((word)(data+2));
+  blitter.dstart = x+y*256; // swapped
+  blitter.solid = color;
+  blitter.flags = DSTSCREEN|FGONLY|SOLID;
+}
+
+inline void erase_sprite_rect(const byte* data, byte x, byte y) {
+  blitter.width = data[0]^4;
+  blitter.height = data[1]^4;
+  blitter.dstart = x+y*256; // swapped
+  blitter.solid = 0;
+  blitter.flags = DSTSCREEN|SOLID;
+}
+
+inline void draw_sprite_strided(const byte* data, byte x, byte y, byte stride) {
+  const byte* src = data+2;
+  byte height = data[1]^4;
+  byte width = data[0]^4;
+  while (height--) {
+    blit_copy(x, y, width, 1, src);
+    y += stride;
+    src += width;
+  }
+}
+
+inline void draw_char(char ch, byte x, byte y, byte color) {
+  if (ch < LOCHAR || ch > HICHAR) return;
+  blit_copy_solid(x, y, 4, 8, font_table[ch - LOCHAR], color);
+}
+
+void draw_string(const char* str, byte x, byte y, byte color) {
+  while (*str) {
+    draw_char(*str++, x, y, color);
+    x += 4;
+  }
+}
+
+typedef struct Actor* a;
+
+typedef void ActorUpdateFn(struct Actor* a);
+typedef void ActorDrawFn(struct Actor* a);
+
+typedef struct Actor {
+  byte grid_index;
+  byte next_actor;
+  byte x,y;
+  byte* shape;
+  ActorUpdateFn* update;
+  ActorDrawFn* draw;
+} Actor;
+
+#define GBITS 4
+#define GDIM (1<<GBITS)
+#define MAX_ACTORS 256
+
+static byte grid[GDIM*GDIM]; // should be 256
+static Actor actors[MAX_ACTORS];
+
+inline byte xy2grid(byte x, byte y) {
+  return (x >> (8-GBITS)) | (y & ((GDIM-1) << GBITS));
+}
+
+void insert_into_grid(byte gi, byte actor_index) {
+  actors[actor_index].grid_index = gi;
+  actors[actor_index].next_actor = grid[gi];
+  grid[gi] = actor_index;
+}
+
+void delete_from_grid(byte gi, byte actor_index) {
+  byte i = grid[gi];
+  if (i == actor_index) {
+    grid[gi] = actors[actor_index].next_actor;
+  } else {
+    do {
+      byte j = actors[i].next_actor;
+      if (j == actor_index) {
+        actors[i].next_actor = actors[actor_index].next_actor;
+        break;
+      }
+      i = j;
+    } while (1);
+    // watchdog reset if actor not found to delete
+  }
+}
+
+void draw_actor_debug(struct Actor* a) {
+  draw_sprite_solid(a->shape, a->x, a->y, a->next_actor?0xff:0x33);
+}
+
+void update_actor(byte actor_index) {
+  struct Actor* a = &actors[actor_index];
+  byte gi0,gi1;
+  if (!a->shape) return;
+  gi0 = a->grid_index;
+  draw_sprite_solid(a->shape, a->x, a->y, 0);
+  if (a->update) a->update(a);
+  if (a->draw) a->draw(a);
+  //draw_sprite_strided(a->shape, a->x, a->y, 2);
+  gi1 = xy2grid(a->x, a->y);
+  if (gi0 != gi1) {
+    delete_from_grid(gi0, actor_index);
+    insert_into_grid(gi1, actor_index);
+  }
+}
+
+//
+
+word lfsr = 1;
+
+word rand() {
+  byte lsb = lfsr & 1;
+  lfsr >>= 1;
+  if (lsb) lfsr ^= 0xd400;
+  return lfsr;
+}
+
+signed char random_dir() {
+  byte x = rand();
+  if (x < 85) return 0;
+  else if (x < 85*2) return -1;
+  else return 1;
+}
+
+void random_walk(Actor* a) {
+  a->x += random_dir();
+  a->y += random_dir();
+}
+
 void main() {
   byte y = 0;
   byte i;
+  byte num_actors = 32;
   blit_solid(0, 0, 255, 255, 0);
+  memset(grid, 0, sizeof(grid));
+  memset(actors, 0, sizeof(actors));
   memcpy(palette, palette_data, 16);
-  draw_sprite(sprite_data, 20, 20);
-  while (1) {
-    for (i=0; i<8; i++) {
-      byte xpos = 40+i*12;
-      const byte* sprdata = sprite_data+2+i*8*16;
-      blit_copy_solid(xpos, y-1, 8, 16, sprdata, 0);
-      blit_copy(xpos, y, 8, 16, sprdata);
-    }
-    y++;
+  fill_char_table();
+  for (i=0; i<num_actors; i++) {
+    Actor* a = &actors[i];
+    a->x = (i & 3) * 16 + 32;
+    a->y = (i / 4) * 16 + 64;
+    a->shape = (void*) all_sprites[i%9];
+    a->update = random_walk;
+    a->draw = draw_actor_debug;
+    insert_into_grid(xy2grid(a->x, a->y), i);
     watchdog0x39 = 0x39;
   }
+  while (1) {
+    for (i=0; i<num_actors; i++) {
+      update_actor(i);
+      watchdog0x39 = 0x39;
+    }
+    y++;
+  }
 }
diff --git a/src/platform/mw8080bw.js b/src/platform/mw8080bw.js
index 422a0506..fe200eff 100644
--- a/src/platform/mw8080bw.js
+++ b/src/platform/mw8080bw.js
@@ -3,7 +3,8 @@
 // http://www.computerarcheology.com/Arcade/
 
 var MW8080BW_PRESETS = [
-  {id:'game2.c', name:'Game #2'},
+  {id:'game2.c', name:'Shoot-em-up Game'},
+  {id:'shifter.c', name:'Sprite w/ Bit Shifter'},
 ];
 
 var Midway8080BWPlatform = function(mainElement) {
diff --git a/src/ui.js b/src/ui.js
index 1021ba9b..eb8514ee 100644
--- a/src/ui.js
+++ b/src/ui.js
@@ -142,8 +142,7 @@ function newEditor(mode) {
   editor.on('changes', function(ed, changeobj) {
     clearTimeout(timer);
     timer = setTimeout(function() {
-      var text = editor.getValue() || "";
-      setCode(text);
+      setCode(editor.getValue());
     }, 200);
   });
   editor.setOption("mode", mode);
@@ -170,10 +169,9 @@ function updatePreset(current_preset_id, text) {
 function loadCode(text, fileid) {
   var tool = platform.getToolForFilename(fileid);
   newEditor(tool && TOOL_TO_SOURCE_STYLE[tool]);
-  editor.setValue(text);
+  editor.setValue(text); // calls setCode()
   editor.clearHistory();
   current_output = null;
-  setCode(text);
   setLastPreset(fileid);
 }
 
@@ -378,6 +376,7 @@ function setCompileOutput(data) {
     editor.setGutterMarker(line, "gutter-info", div);
   }
   if (data.errors.length > 0) {
+    // TODO: move cursor to error line if offscreen?
     toolbar.addClass("has-errors");
     editor.clearGutter("gutter-info");
     var numLines = editor.lineCount();
@@ -638,6 +637,7 @@ function constraintEquals(a,b) {
   return null;
 }
 
+// TODO: move to file
 function _traceInstructions(pc, minclocks, maxclocks, subaddr, constraints) {
   //console.log("trace", hex(pc), minclocks, maxclocks);
   if (!minclocks) minclocks = 0;
diff --git a/tools/Makefile b/tools/Makefile
index a80d98ab..f37ab422 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -30,3 +30,7 @@ ship1.pbm: ship1.png
 
 %.rot.pbm: %.pbm
 	convert $< -transpose -bordercolor white -border 4x4 $@
+
+baddies-horiz.rot.pbm: baddies-horiz.png
+	convert $< +dither -brightness-contrast 50x50 -fill black -transpose -negate $@
+	convert $@ foo.png