Communications: electrical – Digital comparator systems
Patent
1975-05-05
1977-01-18
Chapnick, Melvin B.
Communications: electrical
Digital comparator systems
G06F 304
Patent
active
040042774
ABSTRACT:
Switching apparatus and methods are disclosed by which one or more secondary computers of a loosely-coupled multiprocessing system may communicate directly with selected items of active peripheral equipment of a main computer of the system. This invention, which is an improvement over device-sharing means and indirect-accessing methods of the prior art, may be applied to existing computer systems without modification to any element of their hardware and without modification to the operating system software of the main computer. An essentially autonomous "intelligent switch," connected to an input/output interface (bus) of each processor and completely transparent to the main processor, is used to switch one or more items of operating peripheral equipment from the main computer to a secondary computer in response to asynchronous service requests from the secondary computer. Two modes of operation are provided: Interface Capture and Data Capture. Interface Capture provides a means for temporarily borrowing items of peripheral equipment having off-line operating capabilities, such as buffered line-printers, and is performed during a normal off-line operation of such equipment. With Interface Capture, the requesting secondary computer obtains complete control of the captured item of peripheral equipment for an arbitrary period of time. Data Capture, on the other hand, is designed for use primarily with direct-access auxiliary storage devices and is performed while a device is executing a read or write operation initiated by the main computer. Data Capture provides a secondary computer with the means for directly accessing shared data space in auxiliary storage without, however, requiring the secondary computer to duplicate or replicate the access-method software and input/output hardware capabilities of the main computer system. Instead, the secondary computer draws parasitically upon the hardware and software resources of the main computer to access the requested data space. Unlike indirect-accessing methods of the prior art, however, this is accomplished without burdening the main processor, its main storage, and its input/output channels with the overhead tasks of buffering data blocks and dispatching data to or from the requesting secondary computer.
REFERENCES:
patent: 3214739 (1965-10-01), Gountanis et al.
patent: 3253262 (1966-05-01), Wilenitz et al.
patent: 3274561 (1966-09-01), Hallman et al.
patent: 3510844 (1970-05-01), Aranyi et al.
patent: 3593302 (1971-07-01), Saito et al.
patent: 3623014 (1971-11-01), Doelz et al.
patent: 3634830 (1972-01-01), Baskin
patent: 3641505 (1972-02-01), Artz et al.
patent: 3680052 (1972-07-01), Arulpragasam et al.
patent: 3702462 (1972-11-01), England
patent: 3771134 (1973-11-01), Huettner et al.
Berger Peter L.
Chapnick Melvin B.
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