Abstract: A programmable filter for the read channel of a magnetic recording device filters the sensed signals corresponding to data on magnetic media at at least two different transfer speeds of the magnetic media. The programmable filter, under microprocessor control, selectively switches its filter characteristics without affecting the quality of the filter but changing the cut-off frequency so as to correspond to the two different transfer speeds. The programmable filter of the present invention utilizes solid state switches to implement the switching of the filter characteristics to change the cut-off frequency without affecting the quality. The programmable filter is inductorless and is designed only with resistors and capacitors arranged in a filter network. The programmable filter does not use operational amplifiers, using instead low cost transistors in an emitter-follower configuration.

Abstract: An interchangeable adapter module allows a circuit board, tape cartridge system, or other add-on device to be readily interfaced with any of a variety of different computer systems. A number of pins extend perpendicularly outward from the device circuit board. An adapter circuit board having a pin connector attached thereto engages these pins to removably secure the adapter module in a plane parallel to the device circuit board. One or more external connectors attached to the adapter circuit board are then plugged into corresponding connectors of the external electronic system. Electrical interface circuitry on the adapter circuit board provides electrical interconnections between a predetermined set of the pins attached to the device, and a predetermined set of the electrical contacts of the external connectors.

Abstract: Apparatus for controlling the operational speed of a peripheral multispeed record/playback device so that the device and a connected computer can communicate at a compatible data rate. When a speed control operation is initiated, the device generates index pulses at a rapid rate. The computer generates a series of n test pulses in response to the generation of the first index pulse. The computer then times how long the n test pulses take to be generated. The peripheral device is then told to run at the data rate represented by how long it took to generate the n test pulses.

Abstract: A tape head positioning system for a tape cartridge drive data backup system having a stepper motor with a lead screw connected to the stepper motor and a follower nut threadedly engaging the lead screw. The follower nut has a formed slot for receiving one end of a lever arm. The other end of the lever arm engages in a formed slot a head mounting assembly carrying the tape head and the lever arm is pivoted a first predetermined distance from the first end and a second predetermined distance from the second end. The ratio of the first predetermined distance to the second predetermined distance determines a mechanical advantage for the system thereby causing an inexpensive coarser stepper motor to effectuate fine adjustments of the tape head.

Abstract: A tape head positioning system for a tape cartridge drive data backup system having a stepper motor with a lead screw connected to the stepper motor and a follower nut threadedly engaging the lead screw. The follower nut has a formed slot for receiving one end of a lever arm. The other end of the lever arm engages in a formed slot a head mounting assembly carrying the tape head and the lever arm is pivoted a first predetermined distance from the first end and a second predetermined distance from the second end. The ratio of the first predetermined distance to the second predetermined distance determines a mechanical advantage for the system thereby causing an inexpensive coarser motor to effectuate fine adjustments of the tape head.

Abstract: Apparatus is disclosed for using a head having narrow write gap to write tracks of information on a tape for subsequent reading by other apparatus including apparatus having heads with a wide read gap. An inter track erase operation is performed prior to the writing operation. Density information is written on a plurality of tracks to indicate the flux reversal signal density used for the writing of user data elsewhere on the tape.