| 摘要 |
A magnet (20) is attached to a slidable tab (12) located on a magnetic tape cartridge (10). The slidable tab is movable between a write-protect position (16) for inhibiting recording on the tape in the cartridge, and a write-enable position (18). An associated recorder has two side-by-side Hall effect sensors (24, 26). When the cartridge is positioned in the recorder, the magnet, depending upon the selected position of the cartridge tab, is directly opposite to, and activates, only one or the other Hall effect sensor. If a first sensor is activated, then a write project circuit of the recorder is energized. If the second sensor is activated, then writing on the tape is permitted. If no cartridge is in the recorder, neither Hall effect sensor is activated, indicating that no cartridge is in place. The cartridge together with the recorder thereby provides write protection as well as a positive indication of the presence of the cartridge in the recorder. |
