What Is a CD Drive?

By Jason Artman

A computer is only as useful as the software that runs on it -- and as long as computers have been available, engineers have worked to devise faster and larger storage solutions to enable efficient software delivery. First announced in 1984 as the result of a collaboration between Sony and Philips, the CD-ROM drive -- or just "CD drive" -- quickly became a must-have computer accessory among those who could afford one.

About CD Drives

A CD drive is a device a computer uses to read data encoded digitally on a compact disc. A CD drive may be installed inside a computer's chassis with an opening for disc tray access or a peripheral connected to one of the computer's ports. The acronym "CD-ROM" is short for "Compact Disc Read-Only Memory." Sony and Philips jointly developed the technology in 1984. When the CD-ROM was first created, it could store up to 650MB of data. Newer disc-authoring technologies have since increased the capacity of CD-ROMs.

History of CD Drives

An audio CD stores music as binary code -- zeros and ones -- just like the code used by computers. After Sony and Philips finalized the audio CD standard in 1980, the format was adapted to store computer data as well. When CD-ROM drives appeared on the market in 1985, many consumers couldn't afford and had no need for them. The CD format was primarily used to store extremely large databases. By the early 1990s, though, personal computers had become more powerful, and games were released to demonstrate this power. Titles such as "Myst" and "The 7th Guest" -- both released in 1993 -- contained extensive pre-rendered video scenes that made the games much too large to fit on floppy disks. This -- combined with the fact that CD drives were becoming more affordable -- helped to cement the CD drive's status as the computer storage device of choice.

Types of CD Drives

CD drives have seen numerous enhancements since they were first released. The first CD drives read data at just 150 kilobytes per second. This speed became known as "1X." By the 2000s, "52X" CD drives could transfer data at up to 7.8 megabytes per second. CD drives have also evolved in terms of their connectivity options. The first CD drives required dedicated controller cards -- add-on cards that were inserted into computer motherboards and connected to CD drives via cables. Motherboards now have built-in drive controllers and can connect directly to CD drives. External CD drives are also available. These connect to USB, FireWire and other ports and usually work without requiring software installation. In addition, most current CD drives can "burn" data to recordable discs.

Advantages of CD Drives

When CD drives became affordable enough for consumers, their greatest advantage was that they could store vastly more data than the floppy disk. While a high-density 3.5-inch floppy disk could store 1.44MB of data, a CD-ROM stored up to 650MB. Computer games became more exciting than ever and massive reference materials such as encyclopedias no longer required significant physical storage space. The CD-Recordable format proved a further boon to consumers, allowing them to scan and archive entire photo libraries, make digital mixes of their favorite music, and create and distribute their own large software programs.

Disadvantages of CD Drives

Although the CD-ROM disc was undoubtedly the top medium for portable data storage in the 1990s, it wasn't long before DVDs -- and later, the wide availability of broadband Internet connections -- made CD drives obsolete. CD drives have become less common because CDs store significantly less data than DVDs. The cost difference between CD and DVD drives is negligible. Because most software companies distribute their products online, packaging and shipping software on optical discs has largely become an unnecessary expense. As a result, many computers ship without CD or DVD drives.