#define bishop_m_width 49
#define bishop_m_height 49
-static char bishop_m_bits[] = {
+static unsigned char bishop_m_bits[] = {
0x00,0x00,0x00,0x00,0x00,0x00,0xfe,0x00,0x00,0x00,0x00,0x00,0x00,0xfe,0x00,
0x00,0xc0,0x07,0x00,0x00,0xfe,0x00,0x00,0xc0,0x07,0x00,0x00,0xfe,0x00,0x00,
0x38,0x38,0x00,0x00,0xfe,0x00,0x00,0x07,0xc0,0x01,0x00,0xfe,0x00,0x00,0x07,