This supplement updates the first supplement to the original catalog of available PLATO systems instructional materials. The original catalog was published in April 1980 and the first supplement in November 1981. The lessons described in the current publication have been used in actual instructional situations or have had adequate testing to guarantee that the files are in working order. Information for each listing is printed directly from the CERL on-line catalog ("uicat") and includes the subject heading; title with PLATO lesson code name, year of first copyright, and publication year; author; location of author at the time of lesson production; lesson abstract; auxiliary equipment required; completion time; and intended audience. Library of Congress subject headings have been used to catalog the lessons whenever possible, and cross-referencing of the lessons has been provided. Also provided is a listing by title of all the lessons published since the printing of the first supplement, and an updated index to the lesson catalog and catalog supplements. Programs listed range in level of difficulty from elementary through higher education, and cover a wide variety of subject areas including science, medicine, reading, mathematics, languages, business, and teacher education. (LMM)