Volume 20 of Advances in Computers achieves a milestone. It is the Twentieth Anniversary Volume of this serial publication. Volume 1 was
published in 1960 and now Volume 20, published in 1981, continues a long
and unbroken series. Twenty years in terms of computers comprise
several generations. Advances in Computers permits the publication of
in-depth articles of important current interest relating to computers,
information technology, and applications. In addition to their vital current
interest, subjects have been chosen for inclusion in Advances in
Computers because of the expectation that they will be of significance for a
considerable time to come. This publication provides an opportunity for
highly regarded experts to write review or tutorial articles covering a
major segment of their field. It permits the publication of longer survey
articles that have been prepared in a leisurely fashion and that provide an
overall perspective which would otherwise not be possible.