#define bigsolid_width 32
#define bigsolid_height 32
-static char bigsolid_bits[] = {
+static unsigned char bigsolid_bits[] = {
0x00,0x00,0x00,0x00,0x00,0xc0,0x01,0x00,0x00,0xf0,0x07,0x00,0x00,0xfc,0x1f,
0x00,0x00,0xff,0x7f,0x00,0xc0,0xff,0xff,0x01,0xe0,0xff,0xff,0x03,0xe0,0xff,
0xff,0x07,0xe0,0xff,0xff,0x07,0xe0,0xff,0xff,0x07,0xf0,0xff,0xff,0x07,0xf0,