DAC(ID:7992/)

Initial Culler system 

for Display and Analysis Console

Initial version of the graphical online oriented programming system pioneered by Glen Culler
of UCSB and Burton Fried of UCLLRL by Culler and Hoff at TRW. This version was more rudimentary and more exemplary at the same time.

Ran on the specialised Rome ADC AN/FSQ-27 display component

People:
Related languages
DAC => Culler-Fried System   Evolution of
References:
  • Culler, G. J. and Huff, R. W., "Solution of Nonlinear Integral Equations Using On-Line Computer Control" view details Abstract: Experiments have bean carried out using online control of a digital computer to obtain solutions for certain non-linear integral equations. The computer program did not anticipate any particular method of solution; each user constructed his own method during the solution process.
    Easy cases, those for which the straightforward iteration converges, were solved with half as many iterations. Difficult cases that were both globally and locally divergent were solved through careful control by the problem solver. Photographs displaying the solution process for two sample cases are included. Extract: Introduction
    Introduction
    The basic philosophy of on-line computation is principally that the originator of the problem shall, in a fairly detailed fashion, actually direct its solution by the computer, thereby bringing to bear his own insights and knowledge based on the problem's structure or physical significance. To make possible an operation of this sort requires a fairly sophisticated computer with suitable interrupt capability and a form of input-output equipment which provides for rapid, sophisticated displays of graphical or numerical information from the computer, and offers convenient means for controlling the computer's activities by easily and accurately feeding back information to the computer in graphical or numerical form.

    A system of this type can be realized in many ways. At the present time a satisfactory version of the requisite input-output equipment exists in the form of a Display and Analysis Console (MC) developed at Ramo-Wooldridge. This is a console component of AN/FSQ-27 equipment developed under the auspices of R3me Air Development Center, USAF.

    For output, this console has two 17" scopes (with resolutions of 103 lines in each direction) which permit the display of line segments as well as points. Input of information to the computer is accomplished by means of a crosshair, whose position changes in response to a control lever, and whose coordinates are, on push button command, transmitted to the computer, leaving a small cross displayed on the scope; a light gun (photocell) which can be used to select, with complete accuracy, any desired luminous point of a display; a series of push buttons, each of which calls up a sub-routine from the computer (a subset of these have an overlay feature which allows for conveniently changing from one problem to another); and a set of numerical keys used for feeding in numerical information. Using this equipment we have begun to investigate and explore the potentialities of on-line solution of scientific problems, and in particular, to develop the techniques necessary for literally carrying out mathematical analysis at the DAC keyboard. We report here the results of one of our first experimental attempts in this mode of operation.

    To explore the potentialities and characteristics of on-line scientific computing, it is clear that one must attempt to solve a variety of suitably chosen, difficult problems. In order that the results have a content and value beyond a mere exercise in the use of displays, we imposed the following criteria:
    - the problem must be one which presents real difficulties for conventional computer techniques and mathematical analysis;
    - the problem must be one as yet unsolved (for any soluble problem can usually be solved in many ways, and the ability to do so using a new technique may not indicate the latter's real value); and
    - the problem should be one of significance for some area of current scientific research, that is, a problem whose solution is of value in its own right, apart from any interest in the methods used to obtain it.

    Once a problem was selected, we adopted the additional ground rule that the computer program to be used should involve no mathematical or computational methods beyond those needed to construct the basic operations of analysis, thus requiring the user to compose his techniques at the DAC. Extract: Conclusion
    From our experience thus far there is no question concerning the value of this on-line approach for so-called scientific computation problems. In computing the various curves of physical interest-in this first problem (such as A(0) vs. T for constant k and C) the ability to see what was happening and then decide what to do next proved to be both fascinating and efficient. We were able to run through all the cases needed for such a curve and never vary significantly from a solution. On the other hand, when we attempted to find our first solution in a new region of the parameter space, it was often surprisingly difficult.
    It is possible to attack a broad variety of problems not of the form attempted here and to extend our work in this direction. However, we recognize that this form of computing is no panacea. When problems really can be automated, they usually should be, notwithstanding occasional gains in efficiency. Also, within the context or a computing center, this on-line operation only makes sense if the main facility is otherwise occupied while the problem solver is scratching his head to decide what to do. But, finally, we are gratified to see that certain forms of cut and try mathematics will soon be reasonably available on a push button basis for the practitioner of the art of classical analysis.
          in [AFIPS JCC 21] Proceedings of the 1962 Spring Joint Computer Conference in San Francisco, Ca. SJCC 1962 view details
  • Culler, G. J. and Huff, R. W., "Solution of Nonlinear Integral Equations Using On-Line Computer Control" view details Abstract: Experiments have bean carried out using online control of a digital computer to obtain solutions for certain non-linear integral equations. The computer program did not anticipate any particular method of solution; each user constructed his own method during the solution process.
    Easy cases, those for which the straightforward iteration converges, were solved with half as many iterations. Difficult cases that were both globally and locally divergent were solved through careful control by the problem solver. Photographs displaying the solution process for two sample cases are included. Extract: Introduction
    Introduction
    The basic philosophy of on-line computation is principally that the originator of the problem shall, in a fairly detailed fashion, actually direct its solution by the computer, thereby bringing to bear his own insights and knowledge based on the problem's structure or physical significance. To make possible an operation of this sort requires a fairly sophisticated computer with suitable interrupt capability and a form of input-output equipment which provides for rapid, sophisticated displays of graphical or numerical information from the computer, and offers convenient means for controlling the computer's activities by easily and accurately feeding back information to the computer in graphical or numerical form.

    A system of this type can be realized in many ways. At the present time a satisfactory version of the requisite input-output equipment exists in the form of a Display and Analysis Console (MC) developed at Ramo-Wooldridge. This is a console component of AN/FSQ-27 equipment developed under the auspices of R3me Air Development Center, USAF.

    For output, this console has two 17" scopes (with resolutions of 103 lines in each direction) which permit the display of line segments as well as points. Input of information to the computer is accomplished by means of a crosshair, whose position changes in response to a control lever, and whose coordinates are, on push button command, transmitted to the computer, leaving a small cross displayed on the scope; a light gun (photocell) which can be used to select, with complete accuracy, any desired luminous point of a display; a series of push buttons, each of which calls up a sub-routine from the computer (a subset of these have an overlay feature which allows for conveniently changing from one problem to another); and a set of numerical keys used for feeding in numerical information. Using this equipment we have begun to investigate and explore the potentialities of on-line solution of scientific problems, and in particular, to develop the techniques necessary for literally carrying out mathematical analysis at the DAC keyboard. We report here the results of one of our first experimental attempts in this mode of operation.

    To explore the potentialities and characteristics of on-line scientific computing, it is clear that one must attempt to solve a variety of suitably chosen, difficult problems. In order that the results have a content and value beyond a mere exercise in the use of displays, we imposed the following criteria:
    - the problem must be one which presents real difficulties for conventional computer techniques and mathematical analysis;
    - the problem must be one as yet unsolved (for any soluble problem can usually be solved in many ways, and the ability to do so using a new technique may not indicate the latter's real value); and
    - the problem should be one of significance for some area of current scientific research, that is, a problem whose solution is of value in its own right, apart from any interest in the methods used to obtain it.

    Once a problem was selected, we adopted the additional ground rule that the computer program to be used should involve no mathematical or computational methods beyond those needed to construct the basic operations of analysis, thus requiring the user to compose his techniques at the DAC. Extract: Conclusion
    From our experience thus far there is no question concerning the value of this on-line approach for so-called scientific computation problems. In computing the various curves of physical interest-in this first problem (such as A(0) vs. T for constant k and C) the ability to see what was happening and then decide what to do next proved to be both fascinating and efficient. We were able to run through all the cases needed for such a curve and never vary significantly from a solution. On the other hand, when we attempted to find our first solution in a new region of the parameter space, it was often surprisingly difficult.
    It is possible to attack a broad variety of problems not of the form attempted here and to extend our work in this direction. However, we recognize that this form of computing is no panacea. When problems really can be automated, they usually should be, notwithstanding occasional gains in efficiency. Also, within the context or a computing center, this on-line operation only makes sense if the main facility is otherwise occupied while the problem solver is scratching his head to decide what to do. But, finally, we are gratified to see that certain forms of cut and try mathematics will soon be reasonably available on a push button basis for the practitioner of the art of classical analysis.
          in [AFIPS JCC 21] Proceedings of the 1962 Spring Joint Computer Conference in San Francisco, Ca. SJCC 1962 view details