<p>A disc drive apparatus includes a shutter operating pin (6) engageable in a cut-out (9) in a shutter (8) of a disc cartridge (7). The shutter operating pin (6) is carried by a shutter operating arm (10) which is pivotable to cause transverse shift of the shutter operating pin (6) and the shutter (8) to shift the shutter from a closed position at which a disc is maintained in an inaccessible state to an open position at which is the disc is accessible. An arm lock mechanism is provided to lock the shutter operating arm (10) at the shutter fully opened position. The arm lock mechanism is provided in a cartridge holder. The cartridge holder is also provided with a cartridge lock mechanism (16) which includes a cartridge lock pin (15) engageable with a lock pin cut-out (14) in the disc cartridge (7). The cartridge lock mechanism (16) is actuated by means of the shutter operating arm (10) at the fully open position of the shutter, to establish locking engagement of the cartridge lock pin (15) with the lock pin cut-out (14) of the disc cartridge (7). <IMAGE></p>
