#include <peekpoke.h>
#include <string.h>

extern void (*INTVEC)();
#pragma zpsym("INTVEC")

char framecount;

void irq_handler() {
  asm("inc _framecount");
  asm("rti");
}

void irq_setup() {
  INTVEC = irq_handler;
}

// lower 4 bits are background
// upper 2 bits are sprites
const char PALETTE[3] = {
  0b01000001,	// red
  0b11111010,	// green
  0b10111100,	// blue
};

/*{w:8,h:8,brev:1,count:256}*/
const char FONT[256][8] = {
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, { 0x38,0x44,0x6c,0x44,0x54,0x44,0x38,0x00 }, { 0x38,0x7c,0x54,0x7c,0x44,0x7c,0x38,0x00 }, { 0x00,0x28,0x7c,0x7c,0x7c,0x38,0x10,0x00 }, { 0x00,0x10,0x38,0x7c,0x7c,0x38,0x10,0x00 }, { 0x10,0x38,0x38,0x10,0x7c,0x7c,0x10,0x00 }, { 0x00,0x10,0x38,0x7c,0x7c,0x10,0x38,0x00 }, { 0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00 }, { 0xfc,0xfc,0xfc,0xcc,0xcc,0xfc,0xfc,0xfc }, { 0x00,0x00,0x78,0x48,0x48,0x78,0x00,0x00 }, { 0xfc,0xfc,0x84,0xb4,0xb4,0x84,0xfc,0xfc }, { 0x00,0x1c,0x0c,0x34,0x48,0x48,0x30,0x00 }, { 0x38,0x44,0x44,0x38,0x10,0x38,0x10,0x00 }, { 0x10,0x18,0x14,0x10,0x30,0x70,0x60,0x00 }, { 0x0c,0x34,0x2c,0x34,0x2c,0x6c,0x60,0x00 }, { 0x00,0x54,0x38,0x6c,0x38,0x54,0x00,0x00 }, { 0x20,0x30,0x38,0x3c,0x38,0x30,0x20,0x00 }, { 0x08,0x18,0x38,0x78,0x38,0x18,0x08,0x00 }, { 0x10,0x38,0x7c,0x10,0x7c,0x38,0x10,0x00 }, { 0x28,0x28,0x28,0x28,0x28,0x00,0x28,0x00 }, { 0x3c,0x54,0x54,0x34,0x14,0x14,0x14,0x00 }, { 0x38,0x44,0x30,0x28,0x18,0x44,0x38,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x78,0x78,0x00 }, { 0x10,0x38,0x7c,0x10,0x7c,0x38,0x10,0x38 }, { 0x10,0x38,0x7c,0x10,0x10,0x10,0x10,0x00 }, { 0x10,0x10,0x10,0x10,0x7c,0x38,0x10,0x00 }, { 0x00,0x10,0x18,0x7c,0x18,0x10,0x00,0x00 }, { 0x00,0x10,0x30,0x7c,0x30,0x10,0x00,0x00 }, { 0x00,0x00,0x00,0x40,0x40,0x40,0x7c,0x00 }, { 0x00,0x28,0x28,0x7c,0x28,0x28,0x00,0x00 }, { 0x10,0x10,0x38,0x38,0x7c,0x7c,0x00,0x00 }, { 0x7c,0x7c,0x38,0x38,0x10,0x10,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, { 0x10,0x38,0x38,0x10,0x10,0x00,0x10,0x00 }, { 0x6c,0x6c,0x48,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x28,0x7c,0x28,0x28,0x7c,0x28,0x00 }, { 0x20,0x38,0x40,0x30,0x08,0x70,0x10,0x00 }, { 0x64,0x64,0x08,0x10,0x20,0x4c,0x4c,0x00 }, { 0x20,0x50,0x50,0x20,0x54,0x48,0x34,0x00 }, { 0x30,0x30,0x20,0x00,0x00,0x00,0x00,0x00 }, { 0x10,0x20,0x20,0x20,0x20,0x20,0x10,0x00 }, { 0x20,0x10,0x10,0x10,0x10,0x10,0x20,0x00 }, { 0x00,0x28,0x38,0x7c,0x38,0x28,0x00,0x00 }, { 0x00,0x10,0x10,0x7c,0x10,0x10,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x20 }, { 0x00,0x00,0x00,0x7c,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00 }, { 0x00,0x04,0x08,0x10,0x20,0x40,0x00,0x00 }, { 0x38,0x44,0x4c,0x54,0x64,0x44,0x38,0x00 }, { 0x10,0x30,0x10,0x10,0x10,0x10,0x38,0x00 }, { 0x38,0x44,0x04,0x18,0x20,0x40,0x7c,0x00 }, { 0x38,0x44,0x04,0x38,0x04,0x44,0x38,0x00 }, { 0x08,0x18,0x28,0x48,0x7c,0x08,0x08,0x00 }, { 0x7c,0x40,0x40,0x78,0x04,0x44,0x38,0x00 }, { 0x18,0x20,0x40,0x78,0x44,0x44,0x38,0x00 }, { 0x7c,0x04,0x08,0x10,0x20,0x20,0x20,0x00 }, { 0x38,0x44,0x44,0x38,0x44,0x44,0x38,0x00 }, { 0x38,0x44,0x44,0x3c,0x04,0x08,0x30,0x00 }, { 0x00,0x00,0x30,0x30,0x00,0x30,0x30,0x00 }, { 0x00,0x00,0x30,0x30,0x00,0x30,0x30,0x20 }, { 0x08,0x10,0x20,0x40,0x20,0x10,0x08,0x00 }, { 0x00,0x00,0x7c,0x00,0x00,0x7c,0x00,0x00 }, { 0x20,0x10,0x08,0x04,0x08,0x10,0x20,0x00 }, { 0x38,0x44,0x04,0x18,0x10,0x00,0x10,0x00 }, { 0x38,0x44,0x5c,0x54,0x5c,0x40,0x38,0x00 }, { 0x38,0x44,0x44,0x44,0x7c,0x44,0x44,0x00 }, { 0x78,0x44,0x44,0x78,0x44,0x44,0x78,0x00 }, { 0x38,0x44,0x40,0x40,0x40,0x44,0x38,0x00 }, { 0x78,0x44,0x44,0x44,0x44,0x44,0x78,0x00 }, { 0x7c,0x40,0x40,0x78,0x40,0x40,0x7c,0x00 }, { 0x7c,0x40,0x40,0x78,0x40,0x40,0x40,0x00 }, { 0x38,0x44,0x40,0x5c,0x44,0x44,0x3c,0x00 }, { 0x44,0x44,0x44,0x7c,0x44,0x44,0x44,0x00 }, { 0x38,0x10,0x10,0x10,0x10,0x10,0x38,0x00 }, { 0x04,0x04,0x04,0x04,0x44,0x44,0x38,0x00 }, { 0x44,0x48,0x50,0x60,0x50,0x48,0x44,0x00 }, { 0x40,0x40,0x40,0x40,0x40,0x40,0x7c,0x00 }, { 0x44,0x6c,0x54,0x44,0x44,0x44,0x44,0x00 }, { 0x44,0x64,0x54,0x4c,0x44,0x44,0x44,0x00 }, { 0x38,0x44,0x44,0x44,0x44,0x44,0x38,0x00 }, { 0x78,0x44,0x44,0x78,0x40,0x40,0x40,0x00 }, { 0x38,0x44,0x44,0x44,0x54,0x48,0x34,0x00 }, { 0x78,0x44,0x44,0x78,0x48,0x44,0x44,0x00 }, { 0x38,0x44,0x40,0x38,0x04,0x44,0x38,0x00 }, { 0x7c,0x10,0x10,0x10,0x10,0x10,0x10,0x00 }, { 0x44,0x44,0x44,0x44,0x44,0x44,0x38,0x00 }, { 0x44,0x44,0x44,0x44,0x44,0x28,0x10,0x00 }, { 0x44,0x44,0x54,0x54,0x54,0x54,0x28,0x00 }, { 0x44,0x44,0x28,0x10,0x28,0x44,0x44,0x00 }, { 0x44,0x44,0x44,0x28,0x10,0x10,0x10,0x00 }, { 0x78,0x08,0x10,0x20,0x40,0x40,0x78,0x00 }, { 0x38,0x20,0x20,0x20,0x20,0x20,0x38,0x00 }, { 0x00,0x40,0x20,0x10,0x08,0x04,0x00,0x00 }, { 0x38,0x08,0x08,0x08,0x08,0x08,0x38,0x00 }, { 0x10,0x28,0x44,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xfc }, { 0x30,0x30,0x10,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x40,0x40,0x78,0x44,0x44,0x44,0x78,0x00 }, { 0x00,0x00,0x38,0x44,0x40,0x44,0x38,0x00 }, { 0x04,0x04,0x3c,0x44,0x44,0x44,0x3c,0x00 }, { 0x00,0x00,0x38,0x44,0x78,0x40,0x38,0x00 }, { 0x18,0x20,0x20,0x78,0x20,0x20,0x20,0x00 }, { 0x00,0x00,0x3c,0x44,0x44,0x3c,0x04,0x38 }, { 0x40,0x40,0x70,0x48,0x48,0x48,0x48,0x00 }, { 0x10,0x00,0x10,0x10,0x10,0x10,0x18,0x00 }, { 0x08,0x00,0x18,0x08,0x08,0x08,0x48,0x30 }, { 0x40,0x40,0x48,0x50,0x60,0x50,0x48,0x00 }, { 0x10,0x10,0x10,0x10,0x10,0x10,0x18,0x00 }, { 0x00,0x00,0x68,0x54,0x54,0x44,0x44,0x00 }, { 0x00,0x00,0x70,0x48,0x48,0x48,0x48,0x00 }, { 0x00,0x00,0x38,0x44,0x44,0x44,0x38,0x00 }, { 0x00,0x00,0x78,0x44,0x44,0x44,0x78,0x40 }, { 0x00,0x00,0x3c,0x44,0x44,0x44,0x3c,0x04 }, { 0x00,0x00,0x58,0x24,0x20,0x20,0x70,0x00 }, { 0x00,0x00,0x38,0x40,0x38,0x04,0x38,0x00 }, { 0x00,0x20,0x78,0x20,0x20,0x28,0x10,0x00 }, { 0x00,0x00,0x48,0x48,0x48,0x58,0x28,0x00 }, { 0x00,0x00,0x44,0x44,0x44,0x28,0x10,0x00 }, { 0x00,0x00,0x44,0x44,0x54,0x7c,0x28,0x00 }, { 0x00,0x00,0x48,0x48,0x30,0x48,0x48,0x00 }, { 0x00,0x00,0x48,0x48,0x48,0x38,0x10,0x60 }, { 0x00,0x00,0x78,0x08,0x30,0x40,0x78,0x00 }, { 0x18,0x20,0x20,0x60,0x20,0x20,0x18,0x00 }, { 0x10,0x10,0x10,0x00,0x10,0x10,0x10,0x00 }, { 0x30,0x08,0x08,0x0c,0x08,0x08,0x30,0x00 }, { 0x28,0x50,0x00,0x00,0x00,0x00,0x00,0x00 }, { 0x10,0x38,0x6c,0x44,0x44,0x7c,0x00,0x00 }, { 0x38,0x44,0x40,0x40,0x44,0x38,0x10,0x30 }, { 0x48,0x00,0x48,0x48,0x48,0x58,0x28,0x00 }, { 0x0c,0x00,0x38,0x44,0x78,0x40,0x38,0x00 }, { 0x38,0x00,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x28,0x00,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x30,0x00,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x38,0x28,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x00,0x38,0x44,0x40,0x44,0x38,0x10,0x30 }, { 0x38,0x00,0x38,0x44,0x78,0x40,0x38,0x00 }, { 0x28,0x00,0x38,0x44,0x78,0x40,0x38,0x00 }, { 0x30,0x00,0x38,0x44,0x78,0x40,0x38,0x00 }, { 0x28,0x00,0x10,0x10,0x10,0x10,0x18,0x00 }, { 0x10,0x28,0x00,0x10,0x10,0x10,0x18,0x00 }, { 0x20,0x00,0x10,0x10,0x10,0x10,0x18,0x00 }, { 0x28,0x00,0x10,0x28,0x44,0x7c,0x44,0x00 }, { 0x38,0x28,0x38,0x6c,0x44,0x7c,0x44,0x00 }, { 0x0c,0x00,0x7c,0x40,0x78,0x40,0x7c,0x00 }, { 0x00,0x00,0x78,0x14,0x7c,0x50,0x3c,0x00 }, { 0x3c,0x50,0x50,0x7c,0x50,0x50,0x5c,0x00 }, { 0x38,0x00,0x30,0x48,0x48,0x48,0x30,0x00 }, { 0x28,0x00,0x30,0x48,0x48,0x48,0x30,0x00 }, { 0x60,0x00,0x30,0x48,0x48,0x48,0x30,0x00 }, { 0x38,0x00,0x48,0x48,0x48,0x58,0x28,0x00 }, { 0x60,0x00,0x48,0x48,0x48,0x58,0x28,0x00 }, { 0x28,0x00,0x48,0x48,0x48,0x38,0x10,0x60 }, { 0x48,0x30,0x48,0x48,0x48,0x48,0x30,0x00 }, { 0x28,0x00,0x48,0x48,0x48,0x48,0x30,0x00 }, { 0x00,0x10,0x38,0x40,0x40,0x38,0x10,0x00 }, { 0x18,0x24,0x20,0x78,0x20,0x24,0x5c,0x00 }, { 0x44,0x28,0x10,0x7c,0x10,0x7c,0x10,0x00 }, { 0x60,0x50,0x50,0x68,0x5c,0x48,0x48,0x00 }, { 0x08,0x14,0x10,0x38,0x10,0x10,0x50,0x20 }, { 0x18,0x00,0x38,0x04,0x3c,0x44,0x3c,0x00 }, { 0x18,0x00,0x10,0x10,0x10,0x10,0x18,0x00 }, { 0x18,0x00,0x30,0x48,0x48,0x48,0x30,0x00 }, { 0x18,0x00,0x48,0x48,0x48,0x58,0x28,0x00 }, { 0x28,0x50,0x00,0x70,0x48,0x48,0x48,0x00 }, { 0x28,0x50,0x00,0x48,0x68,0x58,0x48,0x00 }, { 0x38,0x04,0x3c,0x44,0x3c,0x00,0x3c,0x00 }, { 0x30,0x48,0x48,0x48,0x30,0x00,0x78,0x00 }, { 0x10,0x00,0x10,0x30,0x40,0x44,0x38,0x00 }, { 0x00,0x00,0x7c,0x40,0x40,0x40,0x00,0x00 }, { 0x00,0x00,0xfc,0x04,0x04,0x00,0x00,0x00 }, { 0x40,0x48,0x50,0x38,0x44,0x08,0x1c,0x00 }, { 0x40,0x48,0x50,0x2c,0x54,0x1c,0x04,0x00 }, { 0x10,0x00,0x10,0x10,0x38,0x38,0x10,0x00 }, { 0x00,0x00,0x24,0x48,0x24,0x00,0x00,0x00 }, { 0x00,0x00,0x48,0x24,0x48,0x00,0x00,0x00 }, { 0x54,0x00,0xa8,0x00,0x54,0x00,0xa8,0x00 }, { 0x54,0xa8,0x54,0xa8,0x54,0xa8,0x54,0xa8 }, { 0xa8,0xfc,0x54,0xfc,0xa8,0xfc,0x54,0xfc }, { 0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10 }, { 0x10,0x10,0x10,0xf0,0x10,0x10,0x10,0x10 }, { 0x10,0xf0,0x10,0xf0,0x10,0x10,0x10,0x10 }, { 0x50,0x50,0x50,0xd0,0x50,0x50,0x50,0x50 }, { 0x00,0x00,0x00,0xf0,0x50,0x50,0x50,0x50 }, { 0x00,0xf0,0x10,0xf0,0x10,0x10,0x10,0x10 }, { 0x50,0xd0,0x10,0xd0,0x50,0x50,0x50,0x50 }, { 0x50,0x50,0x50,0x50,0x50,0x50,0x50,0x50 }, { 0x00,0xf0,0x10,0xd0,0x50,0x50,0x50,0x50 }, { 0x50,0xd0,0x10,0xf0,0x00,0x00,0x00,0x00 }, { 0x50,0x50,0x50,0xf0,0x00,0x00,0x00,0x00 }, { 0x10,0xf0,0x10,0xf0,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0xf0,0x10,0x10,0x10,0x10 }, { 0x10,0x10,0x10,0x1c,0x00,0x00,0x00,0x00 }, { 0x10,0x10,0x10,0xfc,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0xfc,0x10,0x10,0x10,0x10 }, { 0x10,0x10,0x10,0x1c,0x10,0x10,0x10,0x10 }, { 0x00,0x00,0x00,0xfc,0x00,0x00,0x00,0x00 }, { 0x10,0x10,0x10,0xfc,0x10,0x10,0x10,0x10 }, { 0x10,0x1c,0x10,0x1c,0x10,0x10,0x10,0x10 }, { 0x50,0x50,0x50,0x5c,0x50,0x50,0x50,0x50 }, { 0x50,0x5c,0x40,0x7c,0x00,0x00,0x00,0x00 }, { 0x00,0x7c,0x40,0x5c,0x50,0x50,0x50,0x50 }, { 0x50,0xdc,0x00,0xfc,0x00,0x00,0x00,0x00 }, { 0x00,0xfc,0x00,0xdc,0x50,0x50,0x50,0x50 }, { 0x50,0x5c,0x40,0x5c,0x50,0x50,0x50,0x50 }, { 0x00,0xfc,0x00,0xfc,0x00,0x00,0x00,0x00 }, { 0x50,0xdc,0x00,0xdc,0x50,0x50,0x50,0x50 }, { 0x10,0xfc,0x00,0xfc,0x00,0x00,0x00,0x00 }, { 0x50,0x50,0x50,0xfc,0x00,0x00,0x00,0x00 }, { 0x00,0xfc,0x00,0xfc,0x10,0x10,0x10,0x10 }, { 0x00,0x00,0x00,0xfc,0x50,0x50,0x50,0x50 }, { 0x50,0x50,0x50,0x7c,0x00,0x00,0x00,0x00 }, { 0x10,0x1c,0x10,0x1c,0x00,0x00,0x00,0x00 }, { 0x00,0x1c,0x10,0x1c,0x10,0x10,0x10,0x10 }, { 0x00,0x00,0x00,0x7c,0x50,0x50,0x50,0x50 }, { 0x50,0x50,0x50,0xdc,0x50,0x50,0x50,0x50 }, { 0x10,0xfc,0x00,0xfc,0x10,0x10,0x10,0x10 }, { 0x10,0x10,0x10,0xf0,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x1c,0x10,0x10,0x10,0x10 }, { 0xfc,0xfc,0xfc,0xfc,0xfc,0xfc,0xfc,0xfc }, { 0x00,0x00,0x00,0x00,0xfc,0xfc,0xfc,0xfc }, { 0xe0,0xe0,0xe0,0xe0,0xe0,0xe0,0xe0,0xe0 }, { 0x1c,0x1c,0x1c,0x1c,0x1c,0x1c,0x1c,0x1c }, { 0xfc,0xfc,0xfc,0xfc,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x34,0x48,0x48,0x34,0x00,0x00 }, { 0x00,0x70,0x48,0x70,0x48,0x48,0x70,0x40 }, { 0x78,0x48,0x40,0x40,0x40,0x40,0x40,0x00 }, { 0x00,0x7c,0x28,0x28,0x28,0x28,0x28,0x00 }, { 0x78,0x48,0x20,0x10,0x20,0x48,0x78,0x00 }, { 0x00,0x00,0x3c,0x48,0x48,0x30,0x00,0x00 }, { 0x00,0x00,0x48,0x48,0x48,0x70,0x40,0x40 }, { 0x00,0x00,0x28,0x50,0x10,0x10,0x10,0x00 }, { 0x38,0x10,0x38,0x44,0x38,0x10,0x38,0x00 }, { 0x30,0x48,0x48,0x78,0x48,0x48,0x30,0x00 }, { 0x00,0x38,0x44,0x44,0x28,0x28,0x6c,0x00 }, { 0x30,0x40,0x20,0x10,0x38,0x48,0x30,0x00 }, { 0x00,0x00,0x28,0x54,0x54,0x28,0x00,0x00 }, { 0x00,0x10,0x38,0x54,0x54,0x38,0x10,0x00 }, { 0x00,0x38,0x40,0x78,0x40,0x38,0x00,0x00 }, { 0x00,0x30,0x48,0x48,0x48,0x48,0x00,0x00 }, { 0x00,0x78,0x00,0x78,0x00,0x78,0x00,0x00 }, { 0x00,0x10,0x38,0x10,0x00,0x38,0x00,0x00 }, { 0x40,0x30,0x08,0x30,0x40,0x00,0x78,0x00 }, { 0x08,0x30,0x40,0x30,0x08,0x00,0x78,0x00 }, { 0x00,0x08,0x14,0x10,0x10,0x10,0x10,0x10 }, { 0x10,0x10,0x10,0x10,0x10,0x50,0x20,0x00 }, { 0x00,0x10,0x00,0x7c,0x00,0x10,0x00,0x00 }, { 0x00,0x28,0x50,0x00,0x28,0x50,0x00,0x00 }, { 0x30,0x48,0x48,0x30,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x20,0x00,0x00,0x00,0x00 }, { 0x00,0x1c,0x10,0x10,0x50,0x50,0x20,0x00 }, { 0x50,0x28,0x28,0x28,0x00,0x00,0x00,0x00 }, { 0x60,0x10,0x20,0x70,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x78,0x78,0x78,0x78,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, 
};

#pragma rodata-name (push, "SPRITES")
const char SPRITES[2][16*2] = {
  /*{w:16,h:16,brev:1,remap:[4,0,1,2,3,5,6,7,8,9],count:2}*/ 
  {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x02, 0x3F,
  0x35, 0x2A, 0x20, 0x20, 0x20, 0x20, 0x20, 0x3F,
  0x00, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x40, 0xFC,
  0x54, 0xAC, 0x04, 0x04, 0x04, 0x04, 0x04, 0xFC,
  },{
  0x00, 0x19, 0x1F, 0x0A, 0x05, 0x07, 0x0E, 0x1C,
  0x3A, 0x2A, 0x3C, 0x2E, 0x1E, 0x18, 0x0E, 0x07,
  0x00, 0x80, 0x00, 0x00, 0x00, 0xC0, 0xF0, 0x38,
  0xFC, 0xF4, 0x7C, 0xB4, 0xB8, 0x68, 0xF0, 0xE0,
  }
};
#pragma rodata-name (pop)

void main() {
  int i;
  
  // copy tile bitmaps
  memcpy((char*)0x6800, FONT, sizeof(FONT));
  // set up screen
  for (i=0; i<32*32; i++) {
    POKE(0x4000+i, i);
  }
  memcpy((char*)0x5210, PALETTE, 3);
  
  // setup interrupt handler
  irq_setup();

  while (1) {
    // move sprites
    POKE(0x5000, 16);	// sprite 0 x
    POKE(0x5040, 16);	// sprite 0 y
    POKE(0x5080, framecount);	// sprite 0 x
    POKE(0x50C0, 16);	// sprite 1 y
    POKE(0x5100, 0x01);
  }
}