An optical disc changer in which a disc transporter moves a disc from a magazine to an optical disc player for play and then returns the disc to the magazine. An optical counter provides signals to aid in determining the location of the disc transporter with respect to the magazine. A step counter also provides signals to aid in determining the location of the disc transporter with respect to the magazine. The optical counter and step counter cooperate to provide signals to the microcomputer to input the necessary information to the microcomputer for determining the location of the disc transporter in relation to the magazine. The magazine holds discs in a substantially vertical position and the disc transporter moves substantially horizontally with respect to the magazine.