Magnetic tape cartridge with file protect feature.

摘要

A magnetic tape cartridge (11) comprises a device (16) settable to prevent inadvertent recording and thus erasure on the tape. The device (16) comprises a shaft (21) carrying a control disc (18) intermediate its length. The disc 18 either masks a sensor (23) from a light source (22) or allows illumination of the sensor according to its angular setting. The unit (16) is rotatably mounted in a sleeve (12) formed integraliy with a part (11) of the cartridge. The unit 16 has a screwdriver slot (17c) and an indicator (17b). The sensor (23) is connected in a read/write control circuit.