AppleCD was a range of early SCSI

SCSI

Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...

-based CD ROM drives for Apple Macintosh personal computer

Personal computer

A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s, manufactured and sold by Apple Computer

Apple Computer

Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

. Earlier AppleCD drives required a CD caddy in order to be used, while later models used a tray-loading mechanism. The original model introduced in 1988 was simply called the AppleCD SC. Initially it included a fan, but in 1990, Apple removed it as it was unnecessary and attracted a large amount of dust onto the optical read head. The AppleCD SC was limited to 650 MB capacity but this was increased to the standard 750 MB with the AppleCD SC Plus. There was also a version on the CD drive that did not have the Apple logo.

Several other models were made, including the 150, 300, 300e, 300 plus, 600i and 600e plus (model number also represents data reading speed in KB/s). They all include two Centronics

Centronics

Centronics Data Computer Corporation was a pioneering American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name.-The beginning:Centronics began as a division of Wang Laboratories...

 50-pin SCSI ports, and require mains power.