// add the mappings from 0 to null and 1 to notdef
fourMap.addSegment ((short) 0, (short) 1, (short) 0);
for (int i = getFirstChar (); i <= getLastChar (); i++) {
short value = (short) (zeroMap.map ((byte) i) & 0xff);
if (value != 0) {
fourMap.addSegment ((short) i, (short) i,
(short) (value - i));
}
}