Computational Needs and Resources in Crystallography Proceedings of a Symposium, Albuquerque, New Mexico, April 8, 1972. (1973) / Chapter Skim
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Computing Centers and Networks
Computing Centers and Networks
Pages 97-118
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From page 97... ...
Session IV Computing Centers and Networks Session Chairman: S.C. Abrahams 97
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2. Stylized input formats for characteristic crystallographic data and operations.
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It must be emphasized that this problem for us has been reduced to the non-equivalence of the meaning of identical looking FORTRAN statements. We believe we have succeeded in achieving reasonable interchangeability in spite of these problems, so that we are now able to make blocked magnetic tapes on the UNIVAC 1108 capable of being read, compiled, loaded, libraried, and executed to give the same crystallographic results on a variety of other computers.
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From page 100... ...
I believe that groups like this will find, as we have, that when the computer system changes they will have to invest a large amount of time and effort into the conversion of their libraries. I would prefer to see the efforts of this group of talented men directed to the production of better standard codes or new methods of crystallographic computing in an interchangeable form.
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From page 101... ...
the responsibility for providing information for making the system run on specific machines and for checkout of new system releases. Obviously, some program authors have actively contributed in other respects and due acknowledgement of their authorship is given within the program descriptions in Section 1 of this write-up.
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of Orange Free State Portland State College Univ. of Washington, Seattle Oak Ridge National Laboratory Univ.
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Lykos; Regarding computer program packages, their standardization, certification, and dissemination, three NSF-supported activities are in progress that may not be generally known and may be of interest here. First, the Quantum Chemistry Program Exchange which flourished at Indiana University with support from AFOSR for many years serving chemists on an international scale.
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From page 104... ...
Third, Professor Frank Harris who is well established as a quantum chemist, an applied mathematician, and a sophisticated user of large-scale scientific computers, is developing a set of computer programs for users of quantum chemical techniques. He is capitalizing on the fact that the University of Utah has a node in brilliantly conceived ARPA Network by testing the machine independence, reliability, and accuracy of the programs on physically and logically different computer systems via the ARPA Network.
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From page 105... ...
Perhaps Professor Jensen at the University of Washington would care to comment on the advantages of having a computer currently 10 to 30 times faster than his own to reduce the 10 hours per cycle needed for one refinement operation on his protein structure. The above three cases may generate some discussion but I would like to turn attention especially to the broad, intermediate area of routine crystallographic computing in a laboratory with access to several local computers, from the 4000-word minicomputer running the diffractometer to the local computing center.
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From page 106... ...
The "Protein Data Bank" at Brookhaven National Laboratory is gathering coordinates of macromolecules at various levels of resolution as they are submitted. The first set of protein structure factors has been submitted.
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Kennard's library leave some significant work to be done. And finally, with a link to an available computing service (plus provision for diffractometer data)
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three-dimensional effect in two colors and you get the stereo separation by viewing through a colored screen for each eye. You could also use the color for getting color tonality in the molecule.
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The reason for this is that all facets of protein crystallography, from data collection through display of the solved structure, require extensive use of different types of computers: dedicated minicomputers for control of dataacquisition systems, large and powerful number crunchers for the calculations associated with structure determination and refinement, and special computers for dynamic display and manipulation of molecular models. The protein crystallographic computing system that we are trying to develop is shown in Figure 1.
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From page 111... ...
Our successful construction and use of the PDP-8 to IBM 1800 hierarchy has convinced us of the power, convenience and economy of hierarchical systems. In the proposed scheme, our local hierarchical system will provide reliable rapid data collection and preliminary data processing, while access to a national computer network would be the best way to get the necessary computing power for protein structure determination and refinement.
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M cfl § 4-1 a fN CO 60 <0 CM 0)
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From page 113... ...
In addition, the redundancy of hardware within the network should considerably reduce research delays caused by extended computer down time. In conclusion, we would emphasize that hierarchical computing, both at the local level, through sharing resources among many research groups, and at the national level, through connection to a continental computer network, is a practical way for protein crystallographers to satisfy their ever-increasing computational needs while at the same time maintaining a realistic computing budget.
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The question is, "what has to be done now to make the net truly operational on a national level? " Anonymous: In your local computing hierarchy wouldn't it have been just as convenient and a lot cheaper to connect the PDP-8 to a magnetictape drive rather than go to the expense of interfacing it to the IBM 1800?
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The expression "The ARPA Network is a solution looking for a problem" has become a cliche amongst its detractors. As a matter of fact the brilliantly conceived ARPA Network, which was designed to be an experiment and a demonstration in computer networking, constitutes a major challenge to researchers to discover how computer networking can enhance the conduct of research.
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From page 117... ...
Depending on how many host computers and/or local terminals need to be connected, IMF's cost $53 000 to $117 000. It is essential to the integrity of the ARPA Network that the iKP, hardware and software, be modifiable by the Network Manager only.
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From page 118... ...
At the moment a three-fold load increase could be accommodated by the ARPA Network without a noticeable degradation in service. Calvert: What's the capital tied up in this network right now?
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