Fourth installment of a directory published in four parts in "Database" (June and August) and "Online" (July and September) provides descriptions of 12 laserdisk products together with information on the producer, compatibility, type of laserdisk, search and retrieval software, interface with magnetic media, conditions of usage, price, and status.…

This current overview of optical disk technology describes the evolving marketplace for optical products, the use of libraries as test sites for prototype CD-ROM (compact disk read-only-memory) products, CD-ROM developments, new optical technologies, and advances in magnetics. A list of some compact disk manufacturers and a glossary of terms are…