#define bishopP_width 32
#define bishopP_height 32
-static char bishopP_bits[] = {
+static unsigned char bishopP_bits[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x01, 0x00, 0x00, 0x30, 0x06, 0x00,
0x00, 0x0c, 0x18, 0x00, 0x00, 0x03, 0x60, 0x00, 0xc0, 0x00, 0x80, 0x01,
0x20, 0x00, 0x00, 0x02, 0x20, 0x00, 0x00, 0x06, 0x20, 0x00, 0x00, 0x06,