Abstract: An improved method is disclosed for printing a file of spatially related data stored in an interactive text processing system as vector formatted records. The method involves establishing for the printer the number of print positions for the print line, and transferring the field titles which make up the header portion of the file from storage to the print buffer sequentially, along with an indication of the maximum permissible field width until all of the field names have been transferred. The process involves determining when a new print line is to be started for the header data in those situations where more than one print line is necessary to accommodate all of the field name data of the header by determining if the next field in the sequence to be printed will fit in the space left on the print line previously specified and, if not, then entering a carriage return signal after the last transferred field. The process continues until all of the field names have been transferred.

Abstract: A multi-stage current mode differential amplifier is disclosed in which each cascaded stage includes a pair of input transistors which have their bases connected to a common voltage source and a pair of control transistors which have their emitters connected to a common current source. A diode-like device is inserted between the collector of a control transistor in one stage and the emitter of an input transistor of the succeeding stage which increases the input impedance seen by the control transistor, thereby permitting an increase in amplification for that stage. In both embodiments, the current signal is amplified at a higher rate than the rate of increase of the bias currents supplied to the emitters of the control transistors in each stage.

Abstract: A switching arrangement is disclosed which permits storage devices to be shared by two separate controllers, each controller in turn receives commands and transfers the stored data to a different data processing system. The arrangement involves a plurality of subchannels, each of which comprises at least one addressable storage device and two addressable interlocked port switches, each of which functions to connect one side of the subchannel and the device to one of the controllers. The subchannel switching arrangement is characterized by each switch being addressable as if it were another device, which permits the port switches to be implemented with minimal changes to either the controller or the device.

Abstract: A data detection system and method for a bubble memory is disclosed in which the memory is operated in a start-stop mode during reading of data stored in two separate major loops which are stepped concurrently and wherein each major loop comprises interleaved data and no-data cells. The field rotation is controlled so that if the read operation is stopped, a no-bubble cell of each major loop is stopped adjacent the magneto-resistive sensor which provides read data signals to the detector of that major loop. The detector involves a detection cycle comprising a reference portion and a data portion. The signal generated during the data portion is integrated and compared against the integrated value of the signal generated during the previous reference portion. The comparison of two integrated values, one from a data cell and one from a reference cell, produces different results depending on whether a bubble or no-bubble was stored in the data cell.

Abstract: A hermetically sealed, helium filled magnetic disk storage file is disclosed in which a thin walled container encloses the disk file. The container body is clamped between the baseplate of the file and an external mounting bracket which mounts the file to a frame so that the container "floats" relative to both the frame and the baseplate. A double-seamed visco-elastic seal is employed for attaching the cover of the container to the container body.

Abstract: A random access memory system is disclosed in which data stored in two distinct memory locations defined by distinct address signals can be non-destructively read out simultaneously. The system employs a matrix of two-port memory cells, each cell functioning to store one binary bit of data in a conventional cross-coupled common emitter flip-flop. A pair of input/output transistors have their emitters connected to the respective control nodes of the static cell, their bases connected to first and second word lines, and their collectors connected to first and second bit sense lines. The word lines and bit lines are addressed and pulsed such that during reading of the selected cells, current flows through only one of the input transistors of one of the cells of a sense line whereon, during writing, current flows through both of the input/output transistors, the direction of current flow during writing depending on the value of the binary bit being stored.

Abstract: A microcontroller having a novel addressing arrangement for addressing a storage means containing microinstructions is disclosed. The microcontroller has a fixed machine cycle time for executing each instruction and is arranged to fetch the next instruction during the execution of the current instruction. Branch, conditional branch and non-branch type of instructions are executed.The means for executing instructions is characterized by a plurality of instruction addressable data sources which are selectively connected to the input of the ALU register during the input phase of the machine cycle and a plurality of instruction addressable data destinations which are selectively connected to the output of the ALU register during the output phase of the machine cycle.The means for fetching the next instruction is characterized by a plurality of partial address generators, one of which is the ALU register employed to transfer data from a source to a destination.

Abstract: A system and method attach a second magnetic storage device to a storage subsystem which includes one or more first magnetic storage devices. The track capacity of the first device, i.e., the maximum number of bytes per track, is different from the track capacity of the second device. The information stored on the first device is formatted with a first recording format wherein the start of each individual record measured in the number of bytes from the start of the track varies with either the number of records preceding it, or the length of each preceding record, e.g., a count-key-and-data format.

Abstract: A control system for a serial data channel for a disk file is disclosed in which a microcontroller is used as the control means. The microcontroller has an input port and an output port, while the serial data channel has a data register. The connections of the data register to the input and output port and the parallel by bit input and output busses on which write data and read data is sent provides a plurality of different data transfer loops through the data register which can be selected under the control of the microcontroller. The arrangement permits functions to be achieved by the microcontroller that heretofore were performed by another device connected to the controller or by special hardware.

Abstract: A system for controlling the issuance of a "Sync In" signal by a disk file controller to a control unit to request a byte of data to arrive at the controller at the same predetermined time regardless of the propagation delay of the cables interconnecting the two units. The system includes a circuit arrangement for measuring the actual propagation delay of the interface cable by issuing a "Sync In" signal at a predetermined time and detecting when the return "Sync Out" signal is received. The measured time is converted to a "Sync In" lead time in terms of bits and bytes. This value is stored and subsequently controls circuitry for issuing the "Sync In" pulse at a bit time which provides the exact lead time necessary for the "Sync Out" signal to arrive at the predetermined bit and byte time so that the data byte will be encoded and recorded at the predefined location on the moving magnetic disk.

Abstract: A positioning system for moving a member between positions in time optimal fashion employs concurrent "feedforward" and "feedback" control. The feedforward control system provides major control and the feedback control system provides minor control to correct for deviations between the actual and a nominal system. The feedback loop may thus be of low bandwidth permitting desensitization to high frequency disturbances or the employment of inherently low bandwidth controlled variables.The "feedforward" control function includes successive portions of opposite polarity corresponding to acceleration and deceleration of the member and also includes a subtractive velocity related component. This function represents the approximate current input to an electromagnetic coil actuator of a nominal system required to move such a member between positions in time optimal fashion.

Abstract: A system is disclosed for generating a plurality of error correcting check ECC bytes from a block of data presented to the system in serial by byte form. The system employs a plurality of ECC channels which operate in parallel with the channels generating check bytes from interleaved subsets of the data block. One channel generates an ECC parity check byte for each interleaved subset while another channel generates an ECC locator check byte for each interleaved subset of data. The ECC locator check byte for each subset represents the parity or modulo 2 sum of bit positions which are selected systematically in accordance with a predefined m sequence which is unique to each channel that generates locator check bytes. Error patterns greater than the number of bits in one byte are correctable, as are error patterns which are less than the number of bits in one byte but extend across byte boundaries of two adjacent bytes in different subsets.

Abstract: An air flow system for a disk file is disclosed in which air is pumped under pressure past the disk surfaces to remove contaminants and past a voice coil actuator to cool the motor and returned to an inlet in the pump. A thermostatically controlled air diverter is placed in the air circulating path to reduce the range of temperature change in the disks and thus minimize the track misregistration problems which might occur as a result of differential thermal expansion of the disks and related components. The thermostatically controlled diverter valve functions to control the volume of normally lower temperature ambient air entering the system by controlling the volume of air exhausted from the system in accordance with the temperature of the air being circulated.

Abstract: A system which employs a parallel to serial converter and a serial shift register encoder for encoding a multibyte sync pattern in a fixed rate variable word length run-length limited code wherein less than a single character of data is supplied to the encoder from the parallel to serial converter to encode the multibyte sync pattern. The system provides for feeding a first portion of the encoded sync pattern back to the encoder through a serial decoder which provides a serial bit stream that is identical to the initial pattern provided to the encoder. Suitable control circuitry is employed to control the phasing of the end of the initial bit stream and the beginning of the decoded bit stream fed back to the encoder. Once the feedback path is established, the total length of the encoded sync pattern is independent of the single character initially supplied to the encoder.

Abstract: A voice coil motor having a plurality of independent coils movable within annular flux gaps which are supplied in parallel with flux from a single permanent magnet. The actuator comprises a single permanent magnet mounted to a low reluctance backing plate, a plurality of pole pieces, and a low reluctance casing including an integral pole plate provided with a like plurality of pole piece receiving apertures. The casing extends from the perimeter of the pole plate portion to the backing plate completely surrounding the pole pieces, coils and the magnet.Each pole piece has a rectangular base attached to the permanent magnet and a cylindrical portion which extends into the pole plate portion to define the annular gap, the axis of which is generally normal to the permanent magnet. Adjacent pole pieces abut each other along one edge to assist in maintaining a balanced magnetomotive force to the pole pieces.

Abstract: A sampled data positioning system for moving a member between positions in a minimum time employs a model of the physical system to overcome the low bandwidth constraints of fed back position and velocity samples. The model system is an approximate analog of the physical system and provides continuous pseudo position and velocity signals of high bandwidth. These are applied to a seek controller which generates an error signal between a desired reference velocity trajectory and the pseudo velocity signal. The error signal is fed back to the model system input and is also applied to control the physical system. The model velocity and position outputs are reset at sampling times to the values of the sampled velocity and position in the physical system.

Abstract: Apparatus for converting binary digital data from one form to another according to a variable word length code of fixed rate comprises word position indicating circuitry for indicating predetermined word position states of data in a data storage unit and conversion circuitry for sequentially converting a constant number of input bits at a time into the corresponding number of bits in said other form in dependence upon the contents of the data storage unit and the word position indication. The constant number of bits is less than the number of bits in the longest variable length word in the input data code form. The word position indicating circuitry either generates an updated function representing the current position of the word boundary in the data storage unit or recognizes the boundary from distinctive word ending patterns in the data storage unit.

Abstract: An opaque document scanner in which a moving hologram generates a locus of points from a stationary light beam on an opaque document and the same hologram or a similar one mounted for conjoint movement collects light energy reflected from the document at each point and focuses this energy onto a stationary detector to provide electrical signals corresponding to the information scanned on the document.

Abstract: A storage subsystem comprising a storage control unit and a number of failure independent storage devices, such as disk files, is provided with a check sum generator for generating a check sum segment from segments of a system record as the system record segments are being transferred between the storage subsystem and a CPU of a data processing system. The check sum segments and the associated system record segments are stored on different units so that if one unit containing a system record segment becomes unavailable, the unavailable segment is reconstructed during transfer of the other available segments and the check sum segment to the CPU.

Abstract: In a phase locking oscillator servosystem, the phase of a voltage controlled oscillator (VCO) is determined by a stored control voltage representative of phase error. Positive and negative constant current sources are switched to an integrator, which provides the control voltage, at times determined by a reference input signal and the fed back VCO output. The current sources are switched simultaneously to or away from the integrator in response to a predetermined condition and are switched individually away from or to the integrator in response to respective input and output signals. The conditions for switching are such that a sufficient time interval for switching circuit operation is established between said individual and simultaneous switchings.