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IBM System/370 Systems Principles of Operation

IP.com Disclosure Number: IPCOM000128917D
Original Publication Date: 1981-Jan-01
Included in the Prior Art Database: 2005-Sep-20

Publishing Venue

Software Patent Institute

Related People

IBM International Technical Support Center: AUTHOR [+3]


This publication provides, for reference purposes, a detailed definition of the machine functions performed by System/370. The publication describes each function to the level of detail that must be understood in order to prepare an assembler-language program that relies on that function. It does not, however, describe the notation and conventions that must be employed in preparing such a program, for which the user must instead refer to the appropriate assembler-language publication, such as the OSIVS-DOSIVSE-VM1370 Assembler Language, GC33-4010. The information in this publication is provided principally for use by assembler-language programmers, although anyone concerned with the functional details of System/370 will find it useful. Note that this publication is written as a reference document and should not be considered an introduction or a textbook for System/370. It assumes the user has a basic knowledge of data processing systems and, specifically, the System/370, such as can be derived from the Introduction to IBM Data Processing Systems, GC20-1684, and the IBM System/ System Summary: Processors, GA22-7001. All publications relating to System/370 are listed and described in the IBM System/ and 4300 Processors Bibliography, GC20-0001. All facilities discussed in this publication are not necessarily available on every model of System/370. Furthermore, in some instances the definitions have been structured to allow for some degree of extensibility, and therefore certain capabilities may be described or implied that are not offered on any model. Examples of such capabilities are the provisions for the number of channel-mask bits in the control register, for the size of the CPU address, and for the number of CPUs sharing main storage. The allowance for this type of extensibility should not be construed as implying any intention by IBM to provide such capabilities. For information about the characteristics and availability of features on a specific System/370 model, use the functional characteristics manual for that model. The availability of features on System/370 models is summarized in the IBM System13 70 System Summary: Processors, GA22-7001. Largely because the publication is arranged for reference purposes, certain words and phrases appear, of necessity, earlier in the publication than the principal discussions explaining them. The reader who encounters a problem of this sort should refer to the index, which indicates the location of the key description.

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Reprinted by permission from International Business Machines Corporation copyright 1988

IBM System/370 Systems Principles of Operation

Seventh Edition (March 1980)

Note: The fifth and sixth editions of this publication were inadvertently identified as the fourth and fifth editions, respectively. This edition carries the correct edition number.

This major revision obsoletes GA22-7000-4 and -5 and Technical Newsletters GN22-0498 and GN22-0584. The document has been reorganized and includes Chapter 3, "Storage," which is new and which contains information previously in the chapter "Dynamic-Address Translation," as well as other new information. The chapter "Multiprocessing" has been deleted and the information has been incorporated into Chapter 4, "Control." Many chapters have been extensively revised for clarity.

Because of the extensive reorganization and rewording, it is impractical to identify minor changes. Changes of major technical significance are identified by a vertical bar in the left margin.

Included in this edition are detailed descriptions of the following new items: move inverse, the recovery extensions, and the parts of the extended facility that are independent of the operating system. The move-inverse feature includes the instruction MOVE INVERSE. The recovery- extension feature includes the CLEAR CHANNEL instruction, the machine-check external- damage code and the external-damage-code-validity bit, the channel-not-operational indication, and the logout valid and interface-inoperative bits in the limited channel logout. The parts of the extended facility that are independent of the operating system are the instructions INVALIDATE PAGE TABLE ENTRY and TEST PROTECTION, the common-segment facility, and the low- address protection facility. The parts of the extended facility that are dependent on the operating system are described in the IBM System/ 70 Extended Facility, GA22-7072.

Changes are periodically made to the information herein; before using this publication in connection with the operation of IBM equipment, refer to the latest IBM System/ and 4300 Processors Bibliography, GC20-0001, for the editions that are applicable and current.

It is possible that this material may contain reference to, or information about, IBM products (machines and programs), programming, or services that are not announced in your country. Such references or information must not be construed to mean that IBM intends to announce such IBM products, programming, or services in your country.

Publications are not stocked at the address given below; requests for IBM publications should be made to your IBM representative or to the IBM branch office serving your locality.

A form for reader's comments is provided at the back of this publication. If the form has been removed, comments may be addressed to IBM Corporation, Product Publications, Dept. B98, PO Box 390, Poughkeepsie, NY...