Patent ID: 7295403

Claim:
A second disk cartridge having approximately the same shape as a disk cartridge which has a first recording capacity and a first disk-shaped recording medium within, the second disk cartridge having a second disk-shaped recording medium within and a second recording capacity greater than the first recording capacity, the second disk cartridge comprising: a disk-shaped recording medium to and/or from which data can be written and/or erased; a cartridge body for accommodating the disk-shaped recording medium; write enable/disable detecting holes in the cartridge body for detecting whether data can be written to and/or erased from the disk-shaped recording medium; and a write protect member slidably attached to the cartridge body for opening and closing one of the write enable/disable detecting holes and selectively being operated to move to a write enable position or an write disable position in accordance with the open and closed state thereof, the write enable/disable detecting holes including a first write enable/disable detecting hole at a write enable/disable detecting position for use with a first disk cartridge compatible device and a second write enable/disable detecting hole at a write enable/disable detecting position for use with a second disk cartridge compatible device, the first and second write enable/disable detecting holes being adjacent to each other; and the write protect member being a single member assembled in the positions of the first write enable/disable detecting hole and second write enable/disable detecting hole and is moved to the write disable position or the write enable position of the second write enable/disable detecting hole but is always in place at the write disable position of the first write enable/disable detecting hole.