Compact disc
Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM). Several other formats were further derived from these, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Disc (VCD), Super Video Compact Disc (SVCD), Photo CD, PictureCD, CD-i, and Enhanced Music CD. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan.
AppleCD
The AppleCD SC was the first CD-ROM by Apple Computer Company, introduced in 1988. It originally contained a fan but in 1990 they removed it because it was unneeded and attracted dust onto the optical disk head which could cause problems. It uses a front-loading caddy 1x CD-ROM and is only capable of Read Only Media. This accessory device was only able to read compact disks up to a 650 MB capacity in five formats, CD-Audio, CD-ROM, HFS, ProDOS, and High Sierra. On the front of the device it has an eject button, mini-phono sound out jack, and a volume knob. On the rear it has a power switch, power input, two Centronics 50-pin SCSI outputs, and an audio RCA connector. With appropriate software it would run on any Macintosh with a DB-25 connector, or an Apple II with an Apple II SCSI interface card.