ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLEAIRE -ERN EUROPEAN ORGANIZATION fQfc NUCLEAR «{SEARCH 1989 CERN SCHOOL OF COMPUTIM Bad Herrenalb, Federal Republic of Germany 20 August-2 September 1989 © Copyright CERN, Genève, 1990 Propriété littéraire et sdenlifîque réservée pour Literary and scientific copyrights reserved in all tous Les pays du monde. Ce document ne peu! countries of the world. This report, or wiy part être reproduit nu traduit en tout ou en partie of it, may not be reprinted or translated; without sans ['automation écrite du Directeur général du written permission of the copyright hotder, the CERN. titulaire du droit d'auteur. Dana lea cas Director-tîeneral of ClikN. However, permis­ appropriés, et s'il s'agit d'utiliser le document à sion will be freely grunted for appropriate des Uns nos commerciales, cette autorisation non-commerda! use. sera volontiers accordée, If any patentable invention or registrable design Le CERN ne revendique pas la propriété des is described En the report, CERN makes no claim inventions brevetantes et dessins ou modèles to property rights in it bul offers Lt for the free susceptibles de dépôt qui pourraient être décrits use of research institutions, manufacturers and dans le présent document; ceun-ci peuvent être others. CERN, however, may appose any librement utilisés par les instituts de recherche, attempt by a user to claim any proprietary or les industriels d îutrrcs intéresses. Cependant, le patent rights in sucrt inventions or designs as CERN se réserve le droit de s'opposer a toute may be described in the present document. revendication qu'un usager pourrait faire de La propriété scientifique ou industrielle de toute invention et tout dessin ou modèle décrits dans- le present document, ISSN 0304-2898 ISBN 92-9083-02S-S CERN 90-06 29 May 1990 ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH 1989 CERN SCHOOL OF COMPUTING Bad Herrenalb, Federal Republic of Germany 20 August-2 September 1989 PROCEEDINGS Editor: C. Verkerk GENEVA 1990 CERN — Service d ' Information scientifique — RD/802 - 2500 - mai 1990 ABSTRACT These Proceedings contain written versions of lectures delivered at the 1989 CERN School of Computing and covering a variety of topics. Vector and parallel computing are ihe subjects of five papers: experience with vector processors in HEP; scientific computing with transputers; applications of large transputer arrays; neural networks and neurocomputers; and Amdahl's scaling law. Data-acquisition and event reconstruction methods were covered in two series of lectures reproduced here: microprocessor-based data-acquisition systems for HERA experiments, and track and vertex fitting. Two speakers treated applications of expert systems: artificial intelligence and expert systems -- applications in data acquisition, and application of diagnostic expert systems in the accelerator domain. Other lecture courses covered past and present computing practice; 30 years of computing at CERN, and information processing at the Aerospace Institute in the Federal Republic of Germany. Other papers cover the contents of lectures on: HEPnet, where we are and where we are going; ciphering algorithms; integrated circuit design for supercomputers; GaAs versus Si, theory and practice; and an introduction to operating systems. iii IV PREFACE The twelfth CERN School of Computing took place in September 1989 in Bad Herrenalb, Federal Republic of Germany. Seventy-two students from Lwenty-one countries participated, following lectures and several tutorial sessions. The School was organized in collaboration with the High-Energy Physics Institute of the University of Heidelberg. We are grateful to Professor Klaus Titlel, Dr. Alois Putzer and Dr. Herbert Schleich, whose active support made this School possible. It was a pleasure to collaborate with them. We owe our gratitude to the following organisms and institutions who made substantial financial contributions to the School : Bundesministerium fiir Forschung und Technologic; Minislcrium fur Wissenschaft und Kunst, Baden-Wurtlcmbcrg; Stiftung 600 Jahre Universitilt Heidelberg; and the IBM Stiflungsfonds im Sliflervcrband fur die Deutsche Wisscnschaft. The local organizers did an excellent job, firstly in finding a beautiful and well-suited location for the School, i.e. the Schwarzwald Kulm Hotel in Bad Hcrrenalb, and secondly, in taking care of the many diverse tasks of organizing and coordinating the actions of many people and firms so that everything was ready in time. The lecture programme was highly appreciated by the participants and covered a variety of topics, as these Proceedings show. We were very happy to have special opening lectures by Dr. Georg Bednorz, Professor Emilio Picasso and Professor Paolo Zanella. We extend our thanks to all lecturers for their efforts, which resulted in an interesting programme. The tutorial lectures and laboratory sessions on transputers and Occam were led by Robert Dobinson, assisted by David Jcffcry, Andrew Hamilton, Andrew Jackson and Wcizhao Lu. Their dedicated efforts turned mis part of the School's programme into a success. We are grateful for the collaboration of a number of firms and institutes who lent us material for the tutorial sessions: IBM Germany (in particular the Mannheim and Stuttgart offices), for putting at our disposal 12 PC- ATs; INMOS Ltd., Transtech, and Rutherford Applclon Laboratory for lending transputer boards, and - in the case of INMOS - for offering handbooks and other documentation. We wish to thank the Transputer Support Centre in Southampton for their assistance and advice, and for releasing Andrew Jackson from his normal dntics. The Digital Equipment Corporation, Germany, graciously provided a microVAX and terminals. These were used to set np an electronic mail facility, which was highly appreciated and heavily used by the participants. We gratefully acknowledge their contribution. The staff and management of the Kulm Hotel did everything possible to make our stay enjoyable. A visit to a nearby winery and a guided visit to Heidelberg will remain agreeable souvenirs. Once again it is a pleasure to thank the CERN Editorial Section and Ingrid Barnctt for their efficient assis lance, C. VERKERK Editor V Editor's note: The major pari of the lectures delivered at the 1989 CERN School of Computing have been collected in these Proceedings, but regrettably a few contributions were not received in time. The contents of the paper by S. Nelson covers the lectures given by M. Birriltclla on 'Integrated circuit design for supercomputers, GaAs versus Si, theory and practice1. It is reproduced here in agreement with the speaker and Hie author of the paper. ADVISORY COMMITTEE J.V. ALLABY, CERN, Geneva, Switzerland B. CARPENTER, CERN, Geneva, Switzerland R.F. CHURCHHOUSE, University of Wales, Cardiff, U.K. (Chairman) R.P. MOUNT, CALTEC, Pasadena, U.S.A. (presently at CERN) A. PUTZER, Heidelberg University, Federal Republic of Germany H. SCHLEICH, Heidelberg University, Federal Republic of Germany J.J. THRESHER, CERN, Geneva, Switzerland K. TITTEL, Heidelberg University, Federal Republic of Germany A. VAN DAM, Brown University, Providence, U.S.A. C. VERKERK, CERN, Geneva, Switzerland (Scientific Secretary) D.O. WILLIAMS, CERN, Geneva, Switzerland P. ZANELLA, CERN, Geneva, Switzerland I. BARNETT, CERN, Geneva, Switzerland (School Secretary) vi CONTENTS Page Preface 30 YEARS OF COMPUTING AT CERN 1 P. Zanelta THE SERVICES CONCEPT OF THE DLR CENTRAL DATA 30 PROCESSING DIVISION H. M. Wacker EXPERIENCE WITH VECTOR PROCESSORS IN HEP 58 F. Carmlnati TRANSPUTERS, OCCAM AND GENERAL-PUR POSE 93 PARALLEL COMPUTING A.J.G. Hey APPLICATIONS OF LARGE TRANSPUTER ARRAYS 124 K.C. Bowler HARDWARE AND SOFTWARE TOOLS FOR NEURAL NETWORKS 140 Ph. Treleaven THE USE OF AMDAHL'S SCALED LAW IN DETERMINING 156 THE POWER OF VECTOR COMPUTERS H.M. Wacker EUROPEAN HEPNET -- WHERE WE ARE AND WHERE WE ARE GOING 171 B.E. Carpenter and F. Fliickiger MICROPROCESSOR-BASED DATA ACQUISITION SYSTEMS 179 FOR HERA EXPERIMENTS WJ. Haynes TRACK AND VERTEX FITTING 217 R. Frilhwirth ARTIFICIAL INTELLIGENCE AND EXPERT SYSTEMS - 236 APPLICATIONS IN DATA ACQUISITION K.-fl. Becks APPLICATION OF A DIAGNOSTIC EXPERT SYSTEM 261 IN THE ACCELERATOR DOMAIN E. Malandain VU CIPHERING ALGORITHMS 285 R.F. Churchhou.se INTRODUCTION TO OPERATING SYSTEMS 309 L. Robertson USING SILICON AND GALLIUM ARSENIDE TECHNOLOGIES 337 FOR NEW SUPERCOMPUTER DESIGN S. Nelson THE FUTURE OF FAST NETWORKS 344 G. Millier and M. Salmony LisL of Participants 345 V1JI 30 YEARS OF COMPUTING AT CERN P. Zanella CERN, Geneva, Switzerland 1. INTRODUCTION The origins of computing machinery can be traced back to 3000 years ago when the Chinese introduced a primitive form of abacus, or 300 years ago when Schickard, Pascal and Leibniz invented the first arithmetic machines. For us at CERN it all started 30 years ago when one of the first electronic digital computers, a huge Ferranti Mercury, was installed. It was the beginning of a success story which has changed the way to do physics and, as a matter of fact, to do any work at all in the Laboratory. The story goes on and the changes brought in by the new information technologies continue to affect us at an astonishing rate. Those who witnessed the beginning of the information era were conscious of the potential impact of those marvellous machines on Physics as well as on Society, but they could hardly imagine what was to come. In retrospect, we can say that the 30 years which separate us from the days of those first generation machines, have been years of struggle, of sweat and tears, of doubt and of painful reappraisal, but also years of discovery, of excitement, of achievement and of pride to the actors in this unique adventure. Of those 30 CERN years, I missed only the first three. I did not miss, however, the joys of programming first generation machines, although in a different environment. Actually, when I joined CERN early in 1962, the only machines around were still made out of vacuum tubes. I am, therefore, rather well placed to tell my personal account of the what, why and how of the evolution of automatic computing at CERN.