Abstract: A circuit for encoding and formatting data, the circuit having an input suitable for receiving a data stream in the form of bytes, the circuit comprising firstly a working memory in which the data is stored in the form of a matrix, and from which the data is taken sequentially, with the data being stored and taken by means of respective different sequences (either by being stored in lines and then taken in columns, or else by being stored in columns and then taken in lines), and secondly first and second encoder means each suitable for calculating, respectively for each line and for each column, a given number of redundancy bytes which are respectively horizontal redundancy bytes and vertical redundancy bytes (with one of said encoding means being connected to the outlet of said memory), wherein the first and second encoding means are connected in parallel to the output from the memory, with said second encoding means (for performing redundancy calculations corresponding to the sequence opposite to that by wh

Abstract: A device for providing rotary electric coupling for a recorder/reader of magnetic tape including at least one magnetic head (21, 22) which is rotated at the periphery of an equatorial slot in a cylindrical drum over which the helically wound tape is caused to run. Said device is intended to transmit electrical signals representative of information recorded on or read from said tape, between a rotor-forming rotating portion connected to the head and a stator-forming stationary portion connected to electronic means respectively for emitting and/or receiving said information. The device further includes a two-plate capacitor (29, 42) for each of its heads (21, 22), said capacitor plates being disposed facing each other in pairs and one plate in each pair being fixed to the rotor and the other to the stator.

Abstract: A switch-tuned filter comprises a capacitive filter and a resonant filter both receiving an input signal to be filtered. The resonant filter comprises a gyrator the frequency response of which depends on circuit parameters in two circuit paths therein. A tuning switch is arranged to select the values of the parameters in each of these circuit paths. The output signals of the gyrator and the capacitive filter are combined to form the filtered output signal. The circuit can be used as an equalizer in a magnetic tape recorder.

Abstract: This invention relates to a tape transport for use with a transducer to transport tape along a predetermined path extending past the transducer, comprising two capstans, each disposed at a respective end of the predetermined path; two rollers, each disposed adjacent a respective one of the capstans and arranged to guide tape beyond the respective end of the path in partial wrapping engagement about its respective capstan; two motors each coupled to a respective one of the capstans; and a control circuit coupled to the motors and arranged to control operation thereof to drive the capstans at differing torques whereby to induce a controlled tension in tape extending along the path. One of the motors is driven by an independent source of signals, and the other is driven so as to be dependent, in part, of the operation of the first motor.

Abstract: In a magnetic-tape recorder, tension rollers positioned before and after the tape heads in the tape path have an outer layer of a polyurethane elastomer to absorb vibration of the tape and reduce flutter. Grooves in the elastomer layer enable the effective resilience of the elastomer to be reduced below the bulk value.