A cable used to send audio CD sound to the computer's sound card. When playing audio CDs, CD-ROM drives output analog sound to both a headphones jack and external connector just like a CD player. This method is still the way audio CDs are played on a computer, but it was the only method available on earlier CD-ROM drives for extracting data from an audio CD. By the mid-1990s, most CD-ROM drives could pass the digital data over the computer's bus (see digital audio extraction). PCs today use a standard four-pin cable; however, earlier cards and drives used connectors with three to six pins. Finding the right cable was a problem, and the earliest drives had no connector. An advantage of the multimedia upgrade kits that were popular before CD-ROMs were standard issue on a PC was that they included the card, drive and the correct cable. In lieu of this connection, a stereo cable from the headphones jack of the drive to the AUDIO IN of the sound card could always be used.