How a CD Drive Works


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  Step 1:  Power Connector

The CD drive gets its power from the power supply. It connects to the power supply by a cable and 4-pin connector that plugs into the drive, similar to the ones that plug into your hard drive. If you have no free connectors, you can buy a "Y" cable which will split one connector into two, so that you can use the second connector. But be careful not to overload your power supply with too many peripherals.
  Step 2:  Controller

An IDE/EIDE or SCSI controller inside the computer sends instructions back and forth between your PC and the CD drive, instructing the CD drive to send data to the PC. In most cases, the computer uses the same controller for the hard drive and for the CD drive-and the controller can be either on a separate card or directly on the motherboard. Some older CD drives used a proprietary card, but these days it's best to stick with an EIDE or SCSI controller for ease and compatibility.
  Step 3:  Ribbon Cable

The controller sends and receives information to and from the drive via a 40-pin ribbon cable, if you're using an IDE/EIDE controller. A connector at each end of the cable plugs into the CD drive and into the controller. A SCSI or some type of proprietary controller might use a 32-, 50-, 68- or 72-pin cable.
  Step 4:  Audio Cable

Since CDs include sound and music as well as other kinds of data, they need to send sounds to the PC's sound card. They send data over an audio cable that attaches to the sound card. The sound card, in turn, sends the sound and music to the PC's speakers.
  Step 5:  CD Drive

The CD drive fits into a drive bay on a computer. Most CD drives fit into 5 1/4-inch bays. Screws hold the drive in place inside the bay.