Abstract: The access time in reading data from a read only memory is enhanced by selectively inverting data stored in the memory. Each storage location along a wordline is weighted according to the distance of the bit location from the wordline driver, and bits stored therein are weighted by the bit location weight. The total weights of bits stored along the wordline are summed and compared with the maximum possible sum of weighted bits. If the ratio exceeds a preselected value, all bits of the wordline are inverted. The wordlines of a memory are provided with flag bits to indicate whether or not data stored on the wordline has been inverted.