#define chain_width 13
#define chain_height 7
static unsigned char chain_bits[] = {
   0x00, 0x00, 0xf8, 0x03, 0x04, 0x04, 0x0f, 0x1e, 0x04, 0x04, 0xf8, 0x03,
   0x00, 0x00};
