Two-way communication system for video and digital data
    1.
    发明授权
    Two-way communication system for video and digital data 失效
    用于视频和数字数据的两路通信系统

    公开(公告)号:US3691295A

    公开(公告)日:1972-09-12

    申请号:US3691295D

    申请日:1970-03-31

    Applicant: IBM

    Inventor: FISK DALE E

    CPC classification number: H04L5/1423

    Abstract: Transmission system for jointly linking a video source to a television display device, and a digital data source to a digital data output by means of a single coaxial cable. A video source and the digital data output are located at one end of the coaxial cable, with the television display device and digital data source located in the vicinity of the other end of the cable. Circuit arrangements are provided at the video source end of the cable, and also at the digital data source end of the cable, for respectively separating the video signal and the digital data signal from each other to thereby facilitate the transmission of video information in one direction through the coaxial cable while digital data is simultaneously transmitted through the cable in the other direction.

    INTERNAL BUS ARCHITECTURE FOR A PRIMITIVE INSTRUCTION SET MACHINE

    公开(公告)号:CA1217869A

    公开(公告)日:1987-02-10

    申请号:CA469464

    申请日:1984-12-06

    Applicant: IBM

    Abstract: INTERNAL BUS ARCHITECTURE FOR A PRIMITIVE INSTRUCTION SET MACHINE An internal bus mechanism for implementation in a computing system characterized by having a limited number of primitive general function instructions provided for controlling all system operations. The architecture of the internal bus mechanism defines a bus instruction format which specifies the bus unit being requested, the operation being requested, and sufficient data to specify the operands necessary to perform the requested operations. Two basic classes of instructions are provided, one wherein the CPU waits until a requested operation is performed and the other wherein the CPU issues an instruction to a bus unit and proceeds to execute further instructions in parallel with the operation of the bus unit. If desired, various units of the memory hierarchy may be designated and operated as bus units. To further the philosophy of a primitive instruction set, the present architecture utilizes a small number of bus unit instructions to replace a large number of additional system instructions which would be necessary if the bus units were architected as part of the CPU itself. Hardware design and system protocols are disclosed and described for implementing these architectural objectives.

    ELECTRIC SIGNAL EXCHANGE SWITCHING ARRANGEMENT

    公开(公告)号:CA1035451A

    公开(公告)日:1978-07-25

    申请号:CA223596

    申请日:1975-03-27

    Applicant: IBM

    Abstract: A multiple of telephone or like communications signal transmission lines are interconnected in time division multiplex (TDM) mode by integrated semiconductor switching circuitry. Preferably, electronic solid state structure most suitable for embodying field effect transistors (FET) and like associated devices is arranged in modular chip components permitting extension to large numbers of transmission lines, as desired. Input or calling transmission line terminals are connected to node busses by FET switches in predetermined time sequence under control of a central processing unit. Preferably, a separate timing pulse train generating circuit is used for the switching operation. Output or called transmission line terminals are connected to the node busses in predetermined time sequence at which every calling line is sampled at least once each switching cycle. Signal bandwidth is adjustable by arranging the switching circuitry to sample a calling line one, two, or more times in each switching cycle. Conventional semiconductor structure inherently forms capacitors of substantial reactance between the node busses and points of reference potential. Circuitry is incorporated in the arrangement for discharging the capacitors prior to connecting the input signal lines to the node busses. The circuitry also incorporates FET switch elements arranged for isolating uncalled output terminals from the switching circuitry, and for short circuiting each pair of idle output terminals.

    TIME-DIVISION PULSE-MULTIPLEX DIGITAL ELECTRIC SIGNAL SWITCHING CIRCUIT ARRANGEMENT

    公开(公告)号:CA1037599A

    公开(公告)日:1978-08-29

    申请号:CA223388

    申请日:1975-03-25

    Applicant: IBM

    Abstract: TIME-DIVISION PULSE-MULTIPLEX DIGITAL ELECTRIC SIGNAL SWITCHING CIRCUIT ARRANGEMENT Bilevel or bistatic digital electric signals are transmitted directly through a time division multiplexing (TDM) switching component asynchronously of the TDM clocking pulse train. A pulse duration modulated(PDM) electric signal or like wave is converted to a pulse amplitude modulated (PDM) electric wave having aplitude and timing components indicating a predetermined relationship to the TDM sampling period. The input PDM wave is amplitude limited by conventional circuitry and phase relationship is indicated by a ramp wave generator or a digital counter with the slope of the ramp wave or the counting rate proportional to the sampling period. Other forms of analog-to-digital converter circuitry may be substituted. The converted PAM electric wave is then passed through the switching component in conventional manner. Thereafter, the switched PAM electric wave is analyzed for reconstructing the original PDM electric signal wave. Complementary circuitry us preferably used for regenerating the signal. The upper limit on the data rate corresponds to one transition of the input electric signal to one time division sampling period of the TDM switching component.

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