Abstract: The position of a tape loop in a vacuum chamber is capacitively detected. e capacitive detector includes a flexible electrode that is deflected between a pair of walls parallel to a wall of a vacuum chamber in which the loop is formed by differential pressure in the chamber and by the pressure of a vacuum source having a pressure between the two pressures in the vacuum chamber. Between the flexible electrode and a stationary electrode is a fixed, solid dielectric. The wall includes plural apertures forming separate fluid flow paths. The vacuum source includes a partition with a plurality of apertures forming separate fluid flow paths. The apertures of the wall and partition are aligned and positioned in a direction between opposite ends of the vacuum chamber.

Abstract: The transverse position of a magnetic head relative to reference positions defining even and odd numbered axes between concentric adjacent tracks of a magnetic disc is detected. Each track includes plural position determining, longitudinally extending, equal length cells. The cells have magnetic variations which cause the head to respond to variations in cells of a pair of abutting tracks to derive a series of waveforms respectively having first and second like amplitudes and shapes for even and odd numbered cells as the tracks are translated relative to the head. The waveforms for each of the odd numbered cells include successive equal first amplitude pulses of first and second different polarities. The waveforms for each of the even numbered cells include successive equal second amplitude pulses of first and second different polarities. The number of pulses and approximate shapes of pulses for the even and odd numbered cells are the same.

Abstract: A transistor having an emitter collector path connected in series with a d.c. power supply and a d.c. motor that derives a back emf as a function of motor speed is controlled so current selectively flows from the power supply through the transistor emitter collector path to the motor to drive the motor at differing speeds. The back emf of the motor has a tendency to become excessive for the transistor emitter collector path as the motor speed increases. The voltage of the supply is increased as the back emf increases to prevent the back emf from becoming excessive for the emitter collector path. A control source for the back emf is programmed in accordance with known speed and back emf characteristics of the motor as a function of time. The power supply voltage is increased and decreased in steps in response to variations of the programmed control source being above or below a threshold.

Abstract: Method and device for application, counting and management of asynchronous events emanating from peripheral devices connected to a data processing system. This method enables the system to check and regulate the number of events transmitted to the logic for processing by constitution of tables and working queues managed by the firmware. This invention is applicable principally to input-output checkers associated with the computers.

Abstract: The amplitude of signals read by a head from a magnetic disc is controlled. The disc includes plural concentric tracks, each including data and reference zones. Each reference zone includes plural abutting tracks having a first axis. Each data zone includes a pair of abutting tracks having a second axis, with the first axis being displaced from the second axis by approximately one-half the radial width of a track. The head is desirably positioned so it is centered on a data zone and straddles a pair of reference zones. Each reference zone includes plural cells having magnetic flux transitions which cause the head to derive a pair of opposite polarity pulses as the cells move longitudinally relative to the head. The pulse amplitude is a function of (a) the distance separating the head from the disc, (b) the head radial position, and (c) the presence or absence of faults on the disc.

Abstract: Transducer intended for read/write functions on a magnetic data carrier wherein the data is contained within a plurality of tracks. The transducer includes a magnetic circuit formed by two pole pieces separated by a gap parallel to the carrier, having its larger dimensions perpendicular to the direction of travel of the data of a track and a winding coupled magnetically to this circuit.The larger dimension of the gap varies depending on the nature of the function performed by the transducer. At least one thin layer of magnetic material is deposited across the pole pieces at each outer edge thereof and spaced from each other. The magnetic layers may be deposited in recesses formed in the pole pieces. The pole pieces may be constricted and include thin magnetic layers deposited on the lateral surfaces to channel magnetic flux lines.

Abstract: A data processing system includes apparatus for addressing operands within a segment utilizing segment descriptors. The apparatus is responsive to instruction words executed by a first of a plurality of processes.

Abstract: A head is shifted relative to a magnetic disc for recorded information carried by plural concentric recording tracks on the disc. Addresses of the tracks are recorded on and read by a head from plural reference zones on the disc. The head is shifted from a starting track A to a destination track B by an electric motor. The motor is controlled so the head is accelerated from track A to track C and the head is decelerated when it reaches track C; track C being between tracks A and B. The motor is controlled by calculating an acceleration instruction for the head in response to addresses read by the head and by measuring the head acceleration. The instruction and measured accelerations are combined to derive an error indication that controls the motor.

Abstract: The invention relates to the generation of a digital magnetic recording signal modulated in phase in correspondence with the transitions of the corresponding data signal. According to the invention, the D.C. component of the recording signal is suppressed so that the recording winding can be excited by this signal by means of a transformer. The recording head can include only a single turn.

Abstract: A microprocessor architecture which permits automatic programming of a non-volatile memory included on the same chip as a processing and control unit. The microprocessor includes a permanent memory such as an EPROM which can be electrically written word by word. The microprocessor additionally includes a processing and control unit connected to the permanent memory through two sets of data and address registers. Circuits are also included for distributing memory write voltage in a manner which does not interfere with normal operation of the microprocessor. As a result, the data contents at one memory location can be modified (written) the same time instructions are being read from another memory location. Memory writing can alternatively be effected by a sub-program comprising a sequence of microinstructions, or by a write automaton comprising hard-wired logic circuits.

Abstract: Transducer intended for read and/or write functions on a magnetic data carrier wherein the data is contained within a plurality of tracks. The transducer includes a magnetic circuit formed by two pole pieces separated by a gap parallel to the carrier, having its larger dimension perpendicular to the direction of travel of data on a track and a winding coupled magnetically to this circuit. The transducer is characterized in that it comprises means associated with the pole pieces situated at either side of the gap as seen in the direction of its larger dimension, for channelling the magnetic flux emitted by the immediate magnetic surroundings of the track of the carrier read by the transducer.

Abstract: The relative speed of a movable head and a magnetic disc memory for data orded on a plurality of tracks, each having addresses written in a plurality of reference zones, is determined by reading the addresses read with the head at predetermined sampling times. The speed of the head is calculated as a function of the difference between the addresses read by the head and the interval between the sampling times.

Abstract: An interconnecting substrate according to the invention comprises an insulating base on which rests a set of alternating, superimposed conductive and insulating layers. Contacts are formed on the uppermost insulating layer which border at least one site or zone intended for an integrated circuit chip device whose output conductors are to be connected to the said contacts. Through-connections enable the contacts to be coupled to one of the inner conductive layers. The through-connections include at least one through-connection on the inside of the site relative to at least a predetermined one of the said contacts. A shunt conductor means connected to the predetermined contact has a part outside the site which is connected to an additional contact which serves as a substitute or replaces the said predetermined contact for the connection to the associated output conductor of the chip device.

Abstract: The invention relates to a method and circuit arrangement for magnetic recording of a digital data signal composed of a set of transitions. A recording signal is formed by superposition on the data signal of a high frequency, constant amplitude, magnetic biasing signal S.sub.p. The biasing signal is phase-modulated relative to the data signal transitions. The invention remedies "peak shift" and can be applied to any rectangular or sinusoidal biasing signal.

Abstract: A device for semi-automatic dismantling of a modular component which is soldered and attached to a substrate forming a printed circuit. The component to be dismantled is placed under a hot gas source while a force member applies a resilient thrust, the force member comprising a needle arranged to be placed at the base of the component. The needle is slightly bent to apply a biasing force before controlling the ejection of the hot gas to cause melting of the solder at the ends of the connecting pieces and melting of the adhesive layer by which the component is attached to the substrate.

Abstract: Each card of a set of credit cards includes a memory having plural memory fields. The memory of each card in a set includes a first unalterable multi-bit field indicative of an identification of an external means with which the card can be used, as well as a second unalterable mutli-bit field indicative of operations that can be performed with the card on the external means and an alterable multi-bit field indicative of the number of credit units available to a card holder. Each card includes circuits for controlling the memory, and means for temporarily coupling the memory and circuits to the external means. Each of the first and second unalterable bit fields includes n bits. A change from one bit state to the other bit state of a predetermined number, m, of bits in the unalterable fields of each card in the set is irreversible after imprinting, where m is equal to or less than n.

Abstract: A linear motor for driving a dot printer head includes a carriage carrying print head. The carriage is displaced by a drive system on a linear guide rail. The drive system is a linear motor having an armature wound on a support situated on the carriage. The motor includes an armature winding in a magnetic circuit including the rail.

Abstract: The validity of a code, such as an alpha-numeric code, constituted by a series of elements and including a checking key corresponding to the digit value of the first element of the code, is checked by a memory including an addressable dual-input table having a number of rows at least equal to the maximum number of elements of the code and a number of columns at least equal to all the possible numerical values of the code element. Columns and rows of the table are respectively addressed by the numerical value of a code element and by the relative position of the code elements in the code. The location defined by the intersection of the addressed column and row contains an entry for a remainder resulting from division by a given modulus of the numerical value of the code element multiplied by a coefficient assigned to the position. Each element of the code and the corresponding remainder contained in the location of the memory addressed by the code element are read by a processing means.

Abstract: A data processing method of operation and system uses a processor, an addressable data memory, and an addressable data extension read-write memory. As a data word is written into and read out of the data memory, a data extension associated with the data word may be simultaneously respectively written into and read out of the extension memory. The extension supplements the data word to effectively double the length of the data word. An address bus and control bus cause the simultaneous inputting/outputting of data and extensions to and from the data memory and extension memory respectively. An intermediate storage means is used for inputting and outputting extensions to and from the extension memory. The intermediate storage means includes an interface adapter which interfaces the extension memory to the processor as though the extension memory is a peripheral I/O device. An INTERRUPT is used to alert the processor of the reading of an extended data word.

Abstract: The invention relates to data processing systems making use of an addressable memory. It proposes a process and system permitting qualifying terms to be associated with the data contained in the data memory by writing these qualifying terms at locations associated with the data within a qualifier and set aside for this purpose. These qualifying terms are characteristics of the data or the processing undergone by the data. The qualifier memory, which is interfaced with the processor as though it was a peripheral I/O device, uses an INTERUPT to alert the processor of the occurrence of a call on data which has an associated qualifier.