The Journal for the International Ada Community
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
A Politico-Social History of Algolt (With a Chronology in the Form of a Log Book)
A Politico-Social History of Algolt (With a Chronology in the Form of a Log Book) R. w. BEMER Introduction This is an admittedly fragmentary chronicle of events in the develop ment of the algorithmic language ALGOL. Nevertheless, it seems perti nent, while we await the advent of a technical and conceptual history, to outline the matrix of forces which shaped that history in a political and social sense. Perhaps the author's role is only that of recorder of visible events, rather than the complex interplay of ideas which have made ALGOL the force it is in the computational world. It is true, as Professor Ershov stated in his review of a draft of the present work, that "the reading of this history, rich in curious details, nevertheless does not enable the beginner to understand why ALGOL, with a history that would seem more disappointing than triumphant, changed the face of current programming". I can only state that the time scale and my own lesser competence do not allow the tracing of conceptual development in requisite detail. Books are sure to follow in this area, particularly one by Knuth. A further defect in the present work is the relatively lesser availability of European input to the log, although I could claim better access than many in the U.S.A. This is regrettable in view of the relatively stronger support given to ALGOL in Europe. Perhaps this calmer acceptance had the effect of reducing the number of significant entries for a log such as this. Following a brief view of the pattern of events come the entries of the chronology, or log, numbered for reference in the text. -
Technical Details of the Elliott 152 and 153
Appendix 1 Technical Details of the Elliott 152 and 153 Introduction The Elliott 152 computer was part of the Admiralty’s MRS5 (medium range system 5) naval gunnery project, described in Chap. 2. The Elliott 153 computer, also known as the D/F (direction-finding) computer, was built for GCHQ and the Admiralty as described in Chap. 3. The information in this appendix is intended to supplement the overall descriptions of the machines as given in Chaps. 2 and 3. A1.1 The Elliott 152 Work on the MRS5 contract at Borehamwood began in October 1946 and was essen- tially finished in 1950. Novel target-tracking radar was at the heart of the project, the radar being synchronized to the computer’s clock. In his enthusiasm for perfecting the radar technology, John Coales seems to have spent little time on what we would now call an overall systems design. When Harry Carpenter joined the staff of the Computing Division at Borehamwood on 1 January 1949, he recalls that nobody had yet defined the way in which the control program, running on the 152 computer, would interface with guns and radar. Furthermore, nobody yet appeared to be working on the computational algorithms necessary for three-dimensional trajectory predic- tion. As for the guns that the MRS5 system was intended to control, not even the basic ballistics parameters seemed to be known with any accuracy at Borehamwood [1, 2]. A1.1.1 Communication and Data-Rate The physical separation, between radar in the Borehamwood car park and digital computer in the laboratory, necessitated an interconnecting cable of about 150 m in length. -
Chapter 1. Origins of Mac OS X
1 Chapter 1. Origins of Mac OS X "Most ideas come from previous ideas." Alan Curtis Kay The Mac OS X operating system represents a rather successful coming together of paradigms, ideologies, and technologies that have often resisted each other in the past. A good example is the cordial relationship that exists between the command-line and graphical interfaces in Mac OS X. The system is a result of the trials and tribulations of Apple and NeXT, as well as their user and developer communities. Mac OS X exemplifies how a capable system can result from the direct or indirect efforts of corporations, academic and research communities, the Open Source and Free Software movements, and, of course, individuals. Apple has been around since 1976, and many accounts of its history have been told. If the story of Apple as a company is fascinating, so is the technical history of Apple's operating systems. In this chapter,[1] we will trace the history of Mac OS X, discussing several technologies whose confluence eventually led to the modern-day Apple operating system. [1] This book's accompanying web site (www.osxbook.com) provides a more detailed technical history of all of Apple's operating systems. 1 2 2 1 1.1. Apple's Quest for the[2] Operating System [2] Whereas the word "the" is used here to designate prominence and desirability, it is an interesting coincidence that "THE" was the name of a multiprogramming system described by Edsger W. Dijkstra in a 1968 paper. It was March 1988. The Macintosh had been around for four years. -
High Speed Data Link
High Speed Data Link Vladimir Stojanovic liheng zhu Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2017-72 http://www2.eecs.berkeley.edu/Pubs/TechRpts/2017/EECS-2017-72.html May 12, 2017 Copyright © 2017, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. University of California, Berkeley College of Engineering MASTER OF ENGINEERING - SPRING 2017 Electrical Engineering and Computer Science Physical Electronics and Integrated Circuits Project High Speed Data Link Liheng Zhu This Masters Project Paper fulfills the Master of Engineering degree requirement. Approved by: 1. Capstone Project Advisor: Signature: __________________________ Date ____________ Print Name/Department: Vladimir Stojanovic, EECS Department 2. Faculty Committee Member #2: Signature: __________________________ Date ____________ Print Name/Department: Elad Alon, EECS Department Capstone Report Project High Speed Data Link Liheng Zhu A report submitted in partial fulfillment of the University of California, Berkeley requirements of the degree of Master of Engineering in Electrical Engineering and Computer Science March 2017 1 Introduction For our project, High-Speed Data Link, we are trying to implement a serial communication link that can operate at ~25Gb/s through a noisy channel. We decided to build a parameterized library to allow individual user to set up his/her own parameters according to the project specifications and requirements. -
Fiendish Designs
Fiendish Designs A Software Engineering Odyssey © Tim Denvir 2011 1 Preface These are notes, incomplete but extensive, for a book which I hope will give a personal view of the first forty years or so of Software Engineering. Whether the book will ever see the light of day, I am not sure. These notes have come, I realise, to be a memoir of my working life in SE. I want to capture not only the evolution of the technical discipline which is software engineering, but also the climate of social practice in the industry, which has changed hugely over time. To what extent, if at all, others will find this interesting, I have very little idea. I mention other, real people by name here and there. If anyone prefers me not to refer to them, or wishes to offer corrections on any item, they can email me (see Contact on Home Page). Introduction Everybody today encounters computers. There are computers inside petrol pumps, in cash tills, behind the dashboard instruments in modern cars, and in libraries, doctors’ surgeries and beside the dentist’s chair. A large proportion of people have personal computers in their homes and may use them at work, without having to be specialists in computing. Most people have at least some idea that computers contain software, lists of instructions which drive the computer and enable it to perform different tasks. The term “software engineering” wasn’t coined until 1968, at a NATO-funded conference, but the activity that it stands for had been carried out for at least ten years before that. -
Confine: Automated System Call Policy Generation for Container
Confine: Automated System Call Policy Generation for Container Attack Surface Reduction Seyedhamed Ghavamnia Tapti Palit Azzedine Benameur Stony Brook University Stony Brook University Cloudhawk.io Michalis Polychronakis Stony Brook University Abstract The performance gains of containers, however, come to the Reducing the attack surface of the OS kernel is a promising expense of weaker isolation compared to VMs. Isolation be- defense-in-depth approach for mitigating the fragile isola- tween containers running on the same host is enforced purely in tion guarantees of container environments. In contrast to software by the underlying OS kernel. Therefore, adversaries hypervisor-based systems, malicious containers can exploit who have access to a container on a third-party host can exploit vulnerabilities in the underlying kernel to fully compromise kernel vulnerabilities to escalate their privileges and fully com- the host and all other containers running on it. Previous con- promise the host (and all the other containers running on it). tainer attack surface reduction efforts have relied on dynamic The trusted computing base in container environments analysis and training using realistic workloads to limit the essentially comprises the entire kernel, and thus all its set of system calls exposed to containers. These approaches, entry points become part of the attack surface exposed to however, do not capture exhaustively all the code that can potentially malicious containers. Despite the use of strict potentially be needed by future workloads or rare runtime software isolation mechanisms provided by the OS, such as conditions, and are thus not appropriate as a generic solution. capabilities [1] and namespaces [18], a malicious tenant can Aiming to provide a practical solution for the protection leverage kernel vulnerabilities to bypass them. -
Operating System Support for Run-Time Security with a Trusted Execution Environment
Operating System Support for Run-Time Security with a Trusted Execution Environment - Usage Control and Trusted Storage for Linux-based Systems - by Javier Gonz´alez Ph.D Thesis IT University of Copenhagen Advisor: Philippe Bonnet Submitted: January 31, 2015 Last Revision: May 30, 2015 ITU DS-nummer: D-2015-107 ISSN: 1602-3536 ISBN: 978-87-7949-302-5 1 Contents Preface8 1 Introduction 10 1.1 Context....................................... 10 1.2 Problem....................................... 12 1.3 Approach...................................... 14 1.4 Contribution.................................... 15 1.5 Thesis Structure.................................. 16 I State of the Art 18 2 Trusted Execution Environments 20 2.1 Smart Cards.................................... 21 2.1.1 Secure Element............................... 23 2.2 Trusted Platform Module (TPM)......................... 23 2.3 Intel Security Extensions.............................. 26 2.3.1 Intel TXT.................................. 26 2.3.2 Intel SGX.................................. 27 2.4 ARM TrustZone.................................. 29 2.5 Other Techniques.................................. 32 2.5.1 Hardware Replication........................... 32 2.5.2 Hardware Virtualization.......................... 33 2.5.3 Only Software............................... 33 2.6 Discussion...................................... 33 3 Run-Time Security 36 3.1 Access and Usage Control............................. 36 3.2 Data Protection................................... 39 3.3 Reference -
THE FUTURE of HOME NETWORKING the Impact of Wi-Fi, Remote UI and Open Source Stacks on Service Provider Network Architecture
THE FUTURE OF HOME NETWORKING The Impact of Wi-Fi, Remote UI and Open Source Stacks on Service Provider Network Architecture Business Integration with Clarity The Future of Home Networking | pureIntegration Table of Contents 1 Introduction ................................................................................................. 2 2 Proposed Evolutions .................................................................................... 3 Authentication and WebUI .............................................................................................................. 5 Self-Healing/Diagnostic ................................................................................................................... 6 Security and Content Protection ..................................................................................................... 6 3 Gateway design impact ................................................................................ 7 4 CPE and IoT devices design impact ............................................................... 8 5 Proposed development and integration approach ....................................... 9 Phase 1: Interconnection tests with RDK-B or OpenWrt on Raspberry PI ...................................... 9 Phase 2: Authentication & Remote Management development on Raspberry PI .......................... 9 Phase 3: Port on Production Gateway ............................................................................................ 9 Phase 4: End to End Integration ................................................................................................... -
Systems Architecture of the English Electric KDF9 Computer
Version 1, September 2009 CCS-N4X2 Systems Architecture of the English Electric KDF9 computer. This transistor-based machine was developed by an English Electric team under ACD Haley, of which the leading light was RH Allmark – (see section N4X5 for a full list of technical references). The KDF9 was remarkable because it is believed to be the first zero-address instruction format computer to have been announced (in 1960). It was first delivered at about the same time (early 1963) as the other famous zero-address computer, the Burroughs B5000 in America. A zero-address machine allows the use of Reverse Polish arithmetic; this offers certain advantages to compiler writers. It is believed that the attention of the English Electric team was first drawn to the zero-address concept through contact with George (General Order Generator), an autocode programming system written for a Deuce computer by the University of Sydney, Australia, in the latter half of the 1950s. George used Reversed Polish, and the KDF9 team was attracted to this convention for the pragmatic reason of wishing to enhance performance by minimising accesses to main store. This may be contrasted with the more theoretical line taken independently by Burroughs. To quote Bob Beard’s article in the autumn 1997 issue of Resurrection, the KDF9 had the following architectural features: Zero Address instruction format (a first?); Reverse Polish notation (for arithmetic operations); Stacks used for arithmetic operations and Flow Control (Jumps) and I/O using ferrite cores with a one microsecond cycle; Separate Arithmetic and Main Controls with instruction prefetch; Hardware Multiply and Divide occupying a complete cabinet with clock doubled; Separate I/O control; A word length of 48 bits, comprising six 8-bit 'syllables' (the precursor of the byte). -
Volume 38 Number 1 2011 the Australian Mathematical Society Gazette
Volume 38 Number 1 2011 The Australian Mathematical Society Gazette Amie Albrecht and Kevin White (Editors) Eileen Dallwitz (Production Editor) School of Mathematics and Statistics E-mail: [email protected] The University of South Australia Web: www.austms.org.au/Gazette MawsonLakes, SA5095,Australia Tel: +618 83023754;Fax: +61 8 8302 5785 The individual subscription to the Society includes a subscription to the Gazette. Libraries may arrange subscriptions to the Gazette by writing to the Treasurer. The cost for one volume con- sisting of five issues is AUD 104.50 for Australian customers (includes GST), AUD 120.00 (or USD 114.00) for overseas customers (includes postage, no GST applies). The Gazette publishes items of the following types: • Reviews of books, particularly by Australian authors, or books of wide interest • Classroom notes on presenting mathematics in an elegant way • Items relevant to mathematics education • Letters on relevant topical issues • Information on conferences, particularly those held in Australasia and the region • Information on recent major mathematical achievements • Reports on the business and activities of the Society • Staff changes and visitors in mathematics departments • News of members of the Australian Mathematical Society Local correspondents are asked to submit news items and act as local Society representatives. Material for publication and editorial correspondence should be submitted to the editors. Any communications with the editors that are not intended for publication must be clearly identified as such. Notes for contributors Please send contributions to [email protected]. Submissions should be fairly short, easy to read and of interest to a wide range of readers. -
Status of High Level Architecture Real Time Platform Reference Federation
STATUS OF HIGH LEVEL ARCHITECTURE REAL TIME PLATFORM REFERENCE FEDERATION OBJECT MODEL (RPR FOM) Peter Ryan1, Peter Ross1, Will Oliver1, and Lucien Zalcman2 1Air Operations Division, Defence Science & Technology Organisation (DSTO), 506 Lorimer St, Fishermans Bend, Melbourne, Victoria 3001. Email: [email protected] 2Zalcman Consulting. Email [email protected] ABSTRACT Several advanced distributed simulation architectures and protocols are currently in use to provide simulation interoperability among Live, Virtual, and Constructive (LVC) simulation systems. Distributed Interactive Simulation (DIS) and High Level Architecture (HLA) are the most commonly used protocols/architectures in the simulation community. HLA is a general purpose architecture for distributed computer simulation systems. To enable HLA federates to interoperate with DIS systems, the Real Time Platform Reference Federation Object Model (RPR FOM) was developed. The RPR FOM defines HLA classes, attributes and parameters that are appropriate for real-time, platform-level simulations. This paper provides a discussion of the current interoperability standards, an update on the status of the RPR FOM, and the implications for Australia. 1. INTRODUCTION Advanced Distributed Simulation (ADS) protocols and architectures were created so that various Live-Virtual- Constructive (LVC) systems could interoperate with each other in a simulated game or exercise in the same synthetic battlespace [1]. The simulation nodes may be collocated or may be geographically remote from each other. Interoperability among such LVC systems can be improved using a specifically designed set of predefined interoperability standards. Such predefined sets of interoperability standards are commonly referred to as Modelling and Simulation Standards Profiles (such as the NATO Modelling and Simulation Standards Profile [2]). -
Master Thesis
Charles University in Prague Faculty of Mathematics and Physics MASTER THESIS Petr Koupý Graphics Stack for HelenOS Department of Distributed and Dependable Systems Supervisor of the master thesis: Mgr. Martin Děcký Study programme: Informatics Specialization: Software Systems Prague 2013 I would like to thank my supervisor, Martin Děcký, not only for giving me an idea on how to approach this thesis but also for his suggestions, numerous pieces of advice and significant help with code integration. Next, I would like to express my gratitude to all members of Hele- nOS developer community for their swift feedback and for making HelenOS such a good plat- form for works like this. Finally, I am very grateful to my parents and close family members for supporting me during my studies. I declare that I carried out this master thesis independently, and only with the cited sources, literature and other professional sources. I understand that my work relates to the rights and obligations under the Act No. 121/2000 Coll., the Copyright Act, as amended, in particular the fact that the Charles University in Pra- gue has the right to conclude a license agreement on the use of this work as a school work pursuant to Section 60 paragraph 1 of the Copyright Act. In Prague, March 27, 2013 Petr Koupý Název práce: Graphics Stack for HelenOS Autor: Petr Koupý Katedra / Ústav: Katedra distribuovaných a spolehlivých systémů Vedoucí diplomové práce: Mgr. Martin Děcký Abstrakt: HelenOS je experimentální operační systém založený na mikro-jádrové a multi- serverové architektuře. Před započetím této práce již HelenOS obsahoval početnou množinu moderně navržených subsystémů zajišťujících různé úkoly v rámci systému.