code: function initAttrAddresses() {
  	var i,
  	    result = new Uint16Array( 0x8000 );
  
  	for ( i = 0; i < 0x8000; i++ ) {
  		result[ i ] = 0x23c0 | (i & 0x0c00) | ((i >> 4) & 0x38) | ((i >> 2) & 0x07);
  	}
  
  	return result;
  }
docs: Initialize attribute address lookup table.
  Maps loopy_v values to attribute addresses.