A disc drive designed to hold a cartridge containing an optical data storage disk is compatible with a memory card slot in a host digital electronics device such as a PDA, for example a slot designed for a Type I CompactFlash card. The disc drive contains a body assembly which is inserted into the memory card slot and which has a compatible connector at one end. The disc drive also includes a drive mechanism which contains the spindle motor and optics systems and which is located outside the memory card slot when the drive is in operation. The drive mechanism is lifted from the body assembly to form an opening to a tray into which a cartridge is loaded. The drive mechanism is then pressed against the body assembly to close the cartridge tray and to cause the spindle motor assembly to engage the optical disc within the cartridge. To minimize the extent to which the disc drive protrudes from the host device, part of the cartridge extends into the memory card slot when the disc drive is connected to the host.