void putch(byte page, byte y, char c) {
	int indice, i;

	indice = (c - ' ');
	indice += indice << 2;
	for(i=0; i<5; ++i){
		writeByte(page, y, font5x7[indice]);
		++indice;
		++y;
	}
	writeByte(page, y+6, 0);
}