A cartridge memory used for a tape cartridge includes: a communication unit that communicates with a recording and reproducing device using a wireless communication method defined by an ISO 14443-2 standard which is a wireless communication standard; a non-volatile memory with a storage capacity exceeding 16 KB; and a control unit that writes or reads data to or from the non-volatile memory on a word-by-word basis (2 bytes at a time) or on a block-by-block basis (32 bytes at a time). The non-volatile memory includes a plurality of memory banks each having a storage capacity of 128 KB or less. The control unit writes or reads data defined by a magnetic tape standard to or from one or two or more first memory banks among the plurality of the memory banks, and writes or reads additional data to or from one or two or more second memory banks other than the first memory bank.

A cartridge memory is a cartridge memory used in a recording medium cartridge and includes an antenna section that induces an induced voltage by means of electromagnetic induction, a load modulation section including a load whose magnitude is variable, and a control section that measures the induced voltage and controls the load modulation section on the basis of the measured induced voltage.

A magnetic tape cartridge unit includes a plurality of magnetic tape cartridges stacked in a height direction. Each magnetic tape cartridge includes an antenna coil formed in a substrate, a communication circuit that communicates with a communicatee using power induced by application of a magnetic field from the communicatee to the antenna coil, and a case having a reference plane being a reference in a height direction. The substrate is inclined at an inclination angle of less than 45 degrees with respect to the reference plane. In a case where the plurality of magnetic tape cartridges are stacked in a predetermined orientation in the height direction, the reference planes of the plurality of magnetic tape cartridges are in parallel, and the inclination angles of the substrates relative to the reference planes and positions of the substrates in the reference planes conform among the plurality of magnetic tape cartridges.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information before data recording by the magnetic tape, the information being for adjusting, during data recording or during data reproduction by the magnetic tape, a width of the magnetic tape.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information before data recording by the magnetic tape, the information being for adjusting, during data recording or during data reproduction by the magnetic tape, a width of the magnetic tape.

To provide a magnetic recording medium that has excellent traveling stability in spite of having a thin total thickness and a thin thickness of an underlayer, and is suitable for use in a recording/reproducing device for adjusting the width of the magnetic recording medium by adjusting a tension of the magnetic recording medium in a longitudinal direction thereof. The present technology provides a tape-shaped magnetic recording medium including: a magnetic layer; an underlayer; a base layer; and a back layer, in which the underlayer has a thickness of 0.5 μm or more and 0.9 μm or less, the magnetic recording medium has an average thickness t.sub.T of 5.6 μm or less, the magnetic recording medium includes a lubricant, the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, and the Young's modulus in a longitudinal direction is 7.90 GPa or less.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information during data recording by the magnetic tape, the information being for adjusting a width of the magnetic tape during data reproduction by the magnetic tape.

A cartridge according to the present technology includes: a cartridge case; and a memory. The cartridge case houses a magnetic tape. The memory is provided in the cartridge case, the memory storing information during data recording by the magnetic tape, the information being for adjusting a width of the magnetic tape during data reproduction by the magnetic tape.

According to one embodiment, a disk device includes a housing, recording medium, a magnetic head, an internal wireless communication device, and an internal component. The housing has an internal space. The internal wireless communication device generates at least either of: an electric signal representing information to be written to the recording medium, the electric signal corresponding to light, a magnetic field, or an electric field generated by an external wireless communication device; and light, a magnetic field, or an electric field toward the external wireless communication device, the light, the magnetic field, or the electric field corresponding to an electric signal representing information read from the recording medium. The internal component in the internal space is electrically connected to the magnetic head, the internal component that communicates with an external component located outside the housing through the internal wireless communication device and the external wireless communication device.

According to one embodiment, a disk device includes a housing, recording medium, a magnetic head, an internal wireless communication device, and an internal component. The housing has an internal space. The internal wireless communication device generates at least either of: an electric signal representing information to be written to the recording medium, the electric signal corresponding to light, a magnetic field, or an electric field generated by an external wireless communication device; and light, a magnetic field, or an electric field toward the external wireless communication device, the light, the magnetic field, or the electric field corresponding to an electric signal representing information read from the recording medium. The internal component in the internal space is electrically connected to the magnetic head, the internal component that communicates with an external component located outside the housing through the internal wireless communication device and the external wireless communication device.