public int loadSigned16(int addr){
  return (loadSigned8(addr) << 8) | loadUnsigned8(addr + 1);
}

public int loadSigned16 ( int addr ) { return ( loadSigned8 ( addr ) << 8 ) | loadUnsigned8 ( addr + 1 ) ; }
perform a 16bit load where the sign extended result fills the return value
