static unsigned char screen0[2] = {0,0} ;
static unsigned char screen25[2] = {0,0xaa} ;
static unsigned char screen75[2] = {0xaa,0xff} ;
static unsigned char screen0[2] = {0,0} ;
static unsigned char screen25[2] = {0,0xaa} ;
static unsigned char screen75[2] = {0xaa,0xff} ;