Abstract: A tape recording and playback unit records and reads back data from tape either in a high track density standard format or alternatively reads back data from a tape previously recorded on another unit in accordance with a previous low density standard track format. The unit includes a primary head positioning mechanism for positioning a primary multi-channel write/read head and a secondary head positioning mechanism for positioning a secondary read-only head. The secondary head may be positioned angularly to read longitudinal and azimuth track patterns, and also to be retracted when not needed.

Abstract: A tape recording and playback unit records and reads back data from tape either in a high track density standard format or alternatively reads back data from a tape previously recorded on another unit in accordance with a previous low density standard track format. The unit includes a primary head positioning mechanism for positioning a primary multi-channel write/read head and a secondary head positioning mechanism for positioning a secondary read-only head. The secondary head may be positioned angularly to read longitudinal and azimuth track patterns, and also to be retracted when not needed.

Abstract: A fringe field, capacitive distance sensor for measuring the distance between a probe and the surface of the conductive body. The sensor comprises a conductive plate element mounted by the probe, the thickness of the plate element being substantially less than the height and width of the plate element. The plate element is positioned adjacent to and normal to the body surface, and the fringe field capacitance between the plate element and the body is measured, to thereby determine the distance between the probe and the body surface. The probe may be in contact with and scanned across the body surface, to provide surface profile measurements. A probe including a plurality of plate elements may be positioned inside an opening such as a hole, to measure the geometry of the hole. By maintaining the hole probe adjacent one electrode in contact with the hole wall, both profile and geometry measurements may be made. A noncontacting probe including one or more plate elements may be used to measure surface topography.

Abstract: A fringe field, capacitive distance sensor for measuring the distance between a probe and the surface of the conductive body. The sensor comprises a conductive plate element mounted by the probe, the thickness of the plate element being substantially less than the height and width of the plate element. The plate element is positioned adjacent to and normal to the body surface, and the fringe field capacitance between the plate element and the body is measured, to thereby determine the distance between the probe and the body surface. The probe may be in contact with and scanned across the body surface, to provide surface profile measurements. A probe including a plurality of plate elements may be positioned inside an opening such as a hole, to measure the geometry of the hole. By maintaining the hole probe adjacent one electrode in electrode in contact with the hole wall, both profile and geometry measurements may be made.

Abstract: A module for dust-free containment of rotating data storage media such as disc packs, both in and out of the drive, including top and bottom covers, sliding door access for read/write heads and filtered air, a carrying handle coupled to the media hub for carrying the module and for locking the media in a fixed position within the module while being transported, and a removable chuck plate cover for covering a magnetic chuck plate and for locking the media in a fixed position within the module while being stored.