The magnetic tape cassette is oriented and the position of the detected magnetic tape is determined relative to the orientation of the magnetic tape cassette.

The tape may be mounted in a removable cassette in a similar manner to a magnetic tape cassette.

The virtual tape cassette is implemented by providing a takeup reel (402) positioned with the magnetic tape cartridge (401) in a relationship that substantially matches the format of a magnetic tape cassette.

A magnetic tape cassette driven by a recording/reproducing device capable of similarly operating a plurality of types of magnetic tape cassettes, which does not damage the magnetic cassette at all.

In a second aspect of the present invention, a preselected amount of magnetic tape is detected within the magnetic tape cassette.

An end-less loop, tape cassette (10) contains wound tape (12) with no spool or equivalent rotatable part at the centre of the windings.

This system makes use of a tape cassette helical scan tape transport (415-421) and 3480-type magnetic tape cartridge (401) as the data storage media.

The housing has a loudspeaker (6) and a slot (7) to receive a cassette tape.

By means of the pressing ribs (32), a gap D for containing the information sheets is defined between the lid portion (16) and the magnetic tape cassette (10).

Accordingly, it is possible to provide a magnetic tape cassette which can prevent the shaving of a support shaft pin caused by mutual contact between the support shaft pin and the coil portion of a lid spring.