1.
    发明专利
    未知

    公开(公告)号:FR2312072A1

    公开(公告)日:1976-12-17

    申请号:FR7516536

    申请日:1975-05-21

    Applicant: IBM

    Abstract: An input-output port control subsystem for use with a computer system having separate source and destination buses incorporated therein. Said system including circuitry for controlling operations of said system and said input/output subsystem, said subsystem including a bidirectional input/output bus for transferring data to and from said system, and separate gating means for selectively connecting said source and destination buses to said bidirectional I/O bus. External devices are connected to said bus thru an adaptor unit which is directly connected to said processing system by appropriate control lines. The input/output subsystem is adapted to operate either under programmed I/O control mode thru the central processing system or in cycle steal mode wherein the I/O devices themselves request cycle steal service time on the I/O bus thru their connected adaptor.

    INPUT/OUTPUT PORT CONTROL
    2.
    发明专利

    公开(公告)号:CA1030267A

    公开(公告)日:1978-04-25

    申请号:CA225414

    申请日:1975-04-22

    Applicant: IBM

    Abstract: An input-output port control subsystem for use with a computer system having separate source and destination buses incorporated therein. Said system including circuitry for controlling operations of said system and said input/output subsystem, said subsystem including a bidirectional input/output bus for transferring data to and from said system, and separate gating means for selectively connecting said source and destination buses to said bidirectional I/O bus. External devices are connected to said bus thru an adaptor unit which is directly connected to said processing system by appropriate control lines. The input/output subsystem is adapted to operate either under programmed I/O control mode thru the central processing system or in cycle steal mode wherein the I/O devices themselves request cycle steal service time on the I/O bus thru their connected adaptor.

    3.
    发明专利
    未知

    公开(公告)号:DE2523372A1

    公开(公告)日:1976-01-15

    申请号:DE2523372

    申请日:1975-05-27

    Applicant: IBM

    Abstract: An input-output port control subsystem for use with a computer system having separate source and destination buses incorporated therein. Said system including circuitry for controlling operations of said system and said input/output subsystem, said subsystem including a bidirectional input/output bus for transferring data to and from said system, and separate gating means for selectively connecting said source and destination buses to said bidirectional I/O bus. External devices are connected to said bus thru an adaptor unit which is directly connected to said processing system by appropriate control lines. The input/output subsystem is adapted to operate either under programmed I/O control mode thru the central processing system or in cycle steal mode wherein the I/O devices themselves request cycle steal service time on the I/O bus thru their connected adaptor.

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