TAPE SYSTEM

A tape system having a loader for properly positioning a tape cartridge. The cartridge includes an internal supply reel which is adapted to rotate freely within the cartridge housing when the cartridge is mounted, by means of the loader, onto the supply drive spindle. A spring in the supply drive spindle forces the supply reel to assume a free rotation orientation. The position of the cartridge within the loader is such that lowering the loader causes an eyelet attached to the recording tape in the supply reel of the cartridge to be affixed to a clasp attached to a permanent leader element coupled to the tape deck take-up reel. A plurality of electromechanical sensors on the tape deck is responsive to loading and locking steps to initiate specific electronic actions relating to the tape drive and the data control functions performed by the system processor. The tape is guided past the read/write heads by two pairs of double-post guides. Changes in the tape speed are controlled by a DC command generator which includes a smoothing circuit for controlling a gradual change from one tape speed to another. A tracking window is provided for correctly recovering phase-modulated data from the tape even as the tape speed varies. A control circuit is provided for verifying the presence of a data block.