ABSTRACT
This chapter examines the three primary types of optical disk systems and a hybrid system and their current and expected uses. The system types include read-only, write-once/read-many (WORM), and erasable. These systems are similar in that they all contain a laser source, a disk, and a positioning mechanism to move a recording, reading, or read/write head to a defined position on the disk. The operation of a compact disk read-only memory (CD-ROM) system is based on the creation of a prerecorded optical disk containing the data to be read by the system. Although the WORM disk was eventually coated with either glass or plastic to seal the medium from the effect of an atmospheric reaction, WORM system electronics remained highly complex. CD-ROM and WORM systems provide alternatives to implementing communications access to large, storage-intensive applications on a centralized mainframe. The chapter discusses the primary applications best suited for each type of system.
