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IBM Journal of Research and Development

Issue 6 • Date Nov. 1983

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Displaying Results 1 - 12 of 12
  • System/370 Extended Architecture: Facilities for Virtual Machines

    Publication Year: 1983 , Page(s): 530 - 544
    Cited by:  Papers (24)  |  Patents (114)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1158 KB)  

    This paper describes the evolution of facilities for virtual machines on IBM System/370 computers, and presents the elements of a new architectural facility designed for the virtual-machine environment. Assists that have been added to various System/370 models to support the use of virtual machines are summarized, and a general facility for this purpose which was introduced with the System/370 Extended Architecture (370-XA) is described. A new instruction of the 370-XA architecture places the machine in a specific mode in which several special capabilities are enabled. These allow the machine to provide execution in the virtual-machine environment of most of the instructions (including many privileged instructions) and most of the facilities (such as dynamic address translation) of both the System/370 and the 370-XA architectures. The major features of this new facility are individually discussed and summarized. View full abstract»

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  • On Murphy's Yield Formula

    Publication Year: 1983 , Page(s): 545 - 548
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (351 KB)  

    Some properties of yield are presented, and one lower and three upper bounds for yield are derived. Some of these bounds represent yield formulas already known as useful approximations. Pure Poisson statistics for defect density provides the lower bound. The upper bounds are obtained with mixtures of Poisson distributions and a formula of Price and Stapper. View full abstract»

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  • Modeling of Integrated Circuit Defect Sensitivities

    Publication Year: 1983 , Page(s): 549 - 557
    Cited by:  Papers (157)  |  Patents (6)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (638 KB)  

    Until now only cursory descriptions of mathematical models for defect sensitivities of integrated circuit chips have been given in the yield literature. This paper treats the fundamentals of the defect models that have been used successfully at IBM for a period of more than fifteen years. The effects of very small defects are discussed first. The case of photolithographic defects, which are of the same dimensions as the integrated circuit device and interconnection patterns, is dealt with in the remainder of the paper. The relationships between these models and test sites are described. Data from measurements of defect sizes are discussed. View full abstract»

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  • SLAN-4: A Language for the Specification and Design of Large Software Systems

    Publication Year: 1983 , Page(s): 558 - 576
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1265 KB)  

    The language SLAN-4 has been defined in view of the need for formal tools supporting the specification and design of large software systems. It offers its users language constructs for algebraic and axiomatic specifications as well as for design in pseudocode. One of its major design goals has been to ease subsequent refinements of a (given) specification. The user can start his development with an informal high-level specification which can be formalized and implemented at a later date by using lower-level concepts. This paper provides the formal definitions of the SLAN-4 language, discusses the design decisions, and presents examples for the use of the syntactic constructs. View full abstract»

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  • Replacing Square Roots by Pythagorean Sums

    Publication Year: 1983 , Page(s): 577 - 581
    Cited by:  Papers (2)  |  Patents (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (375 KB)  

    An algorithm is presented for computing a “Pythagorean sum” a ⊕ b = √(a2 + b2) directly from a and b without computing their squares or taking a square root. No destructive floating point overflows or underflows are possible. The algorithm can be extended to compute the Euclidean norm of a vector. The resulting subroutine is short, portable, robust, and accurate, but not as efficient as some other possibilities. The algorithm is particularly attractive for computers where space and reliability are more important than speed. View full abstract»

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  • A Class of Numerical Methods for the Computation of Pythagorean Sums

    Publication Year: 1983 , Page(s): 582 - 589
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (447 KB)  

    Moler and Morrison have described an iterative algorithm for the computation of the Pythagorean sum (a2 + b2)½ of two real numbers a and b. This algorithm is immune to unwarranted floating-point overflows, has a cubic rate of convergence, and is easily transportable. This paper, which shows that the algorithm is essentially Halley's method applied to the computation of square roots, provides a generalization to any order of convergence. Formulas of orders 2 through 9 are illustrated with numerical examples. The generalization keeps the number of floating-point divisions constant and should be particularly useful for computation in high-precision floating-point arithmetic. View full abstract»

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  • Bending and Stretching an Elastic Strip Around a Narrow Cylindrical Drum

    Publication Year: 1983 , Page(s): 590 - 597
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    An analysis is made of the deflected forms assumed by an elastic strip when it is bent and stretched around a rigid drum. A summary is first given of the method of analysis used and the results obtained in a previous study where the drum width is equal to or greater than that of the strip. This work is then extended to the case where the strip width exceeds that of the drum. Deflected forms and contact regions are delineated for a strip-width/drum-width ratio of two and for various values of two parameters: anticlastic deformation and tension. View full abstract»

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  • Automated Twisted-Pair Wire Bonding

    Publication Year: 1983 , Page(s): 598 - 606
    Cited by:  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (770 KB)  

    A need for highly dense and reworkable external interconnections with controlled characteristic impedance on high-performance printed-circuit boards led to the development of the process and equipment described in this paper. These interconnections are required to implement engineering changes, to install precise circuit delays, to repair printed-circuit defects, and to complete interconnections not possible with printed circuitry alone. As an economical way to meet the characteristic impedance requirement of 80 ± 10 Ω and the density requirement for terminations on a 2.5-mm “staggered” grid (twice as dense as a 2.5-mm-square grid), 39-gauge twisted-pair wire is used. A solder-reflow process bonds the wires to the printed circuitry and meets the need for reworkability. Computer-controlled equipment, developed to install twisted-pair wires at production rates, is now being used in several IBM plants worldwide. View full abstract»

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  • Recent Papers by IBM Authors

    Publication Year: 1983 , Page(s): 607 - 613
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (603 KB)  

    Reprints of the papers listed here may usually be obtained by writing directly to the authors. The authors' IBM divisions or groups are identifed as follows: CHQ is Corporate Headquarters; CPD, Communication Products Division; DSD, Data Systems Division; FED, Field Engineering Division; FSD, Federal Systems Division; GPD, General Products Division; GSD, General Systems Division; GTD, General Technology Division; IPD, Information Products Division; ISG, Information Systems Group; IS&CG, Information Systems & Communications Group; IS & TG, Information Systems & Technology Group; NAD, National Accounts Division; NMD, National Marketing Division; RES, Research Division; SPD, System Products Division; and SRI, Systems Research Institute. Papers are listed alphabetically by authors. View full abstract»

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  • Recent IBM Patents

    Publication Year: 1983 , Page(s): 614 - 616
    Save to Project icon | PDF file iconPDF (228 KB)  
    Freely Available from IEEE
  • Author Index for Papers in Volume 27

    Publication Year: 1983 , Page(s): 617 - 619
    Save to Project icon | PDF file iconPDF (183 KB)  
    Freely Available from IEEE
  • Subject Index for Papers in Volume 27

    Publication Year: 1983 , Page(s): 620 - 622
    Save to Project icon | PDF file iconPDF (231 KB)  
    Freely Available from IEEE

Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

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Meet Our Editors

Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center