Abstract: A method and apparatus for digitally representing a waveform segment defined by discrete ordered pairs of abscissae and ordinates, the ordered pairs being divided into an odd set and an even set. The method includes the steps of: for each even abscissa, generating a difference code representing a difference between an even ordinate paired with the even abscissa and the even abscissa, whereby the even ordinate paired with the even abscissa is represented as the sum of the even abscissa and the corresponding difference code; and for each odd abscissa, generating a differential code representing a differential between an odd ordinate paired with the odd abscissa and an even ordinate corresponding to the odd abscissa, whereby the odd ordinate paired with the odd abscissa is represented as the sum of the corresponding even ordinate and the corresponding differential code.