Showing papers on "Personal computer published in 1981"

Remote procedure call

Abstract: Remote procedure call is the synchronous language-level transfer of control between programs in disjoint address spaces whose primary communication medium is a narrow channel. The thesis of this dissertation is that remote procedure call (RPC) is a satisfactory and efficient programming language primitive for constructing distributed systems. A survey of existing remote procedure mechanisms shows that past RPC efforts are weak in addressing the five crucial issues: uniform call semantics, binding and configuration, strong typechecking, parameter functionality, and concurrency and exception control. The body of the dissertation elaborates these issues and defines a set of corresponding essential properties for RPC mechanisms. These properties must be satisfied by any RPC mechanism that is fully and uniformly integrated into a programming language for a homogeneous distributed system. Uniform integration is necessary to meet the dissertation's fundamental goal of syntactic and semantic transparency for local and remote procedures. Transparency is important so that programmers need not concern themselves with the physical distribution of their programs. In addition to these essential language properties, a number of pleasant properties are introduced that ease the work of distributed programming. These pleasant properties are good performance, sound remote interface design, atomic transactions, respect for autonomy, type translation, and remote debugging. With the essential and pleasant properties broadly explored, the detailed design of an RPC mechanism that satisfies all of the essential properties and the performance property is presented. Two design approaches are used: The first assumes full programming language support and involves changes to the language's compiler and binder. The second involves no language changes, but uses a separate translator--a source-to-source RPC compiler--to implement the same functionality. Design decisions crucial to the efficiency of the mechanism are made using a set of RPC performance lessons. These lessons are based on the empirical performance evaluation of a sequence of five working RPC mechanisms, each one faster than its predecessor. Some expected results about the costs of parameter copying, process switching, and runtime type manipulation are confirmed; a surprising result about the price of protocol layering is presented as well. These performance lessons, applied in concert, reduce the roundtrip time for a remote procedure call by a remarkable factor of 35. For moderate speed personal computers communicating over an Ethernet, for example, a simple remote call takes 800 microseconds; on a higher speed personal computer, the same remote call takes 149 microseconds. In both cases the remote call takes about 20 times longer than the same local call. This represents a substantial performance improvement over other operational RPC mechanisms.

Alto: A personal computer

Abstract: The Alto is a small computer system designed in early 1973 as an experiment in personal computing. Its principal characteristics, some of the design choices that led to the implementation, and some of the applications for which the Alto has been used are discussed.

Clinical decision analysis by personal computer.

Abstract: • Decision analysis is a useful clinical tool, but the calculational burden placed on the physician is a major impediment to its application We have developed a computer program, implemented on a personal computer, that guides the physician in constructing and analyzing decision trees and simplifies the performance of sensitivity analysis, the process that assesses the probability and utility data used in an analysis Senior physicians, subspecialty fellows, house staff, and students have used this program to analyze complex patient treatment problems Because the calculational burden is shifted from physician to computer, trade-offs between one clinical variable (eg, the chance that a given disease is present) and another (eg, the risk of treatment) can be rapidly and conveniently assessed This capability provides clinical insights that can be obtained only with great difficulty by previously available methods

Lilith: A personal computer for the software engineer

Abstract: The personal work station offers significant advantages over the large-scale, central computing facility accessed via a terminal. Among them are availability, reliability, simplicity of operation, and a high bandwidth to the user. Modern technology allows to build systems for high-level language programming with significant computing power for a reasonable price.At the Institut fur Informatik of ETH we have designed and built such a personal computer tailored to the language Modula-2. This paper is a report on this project which encompasses language design, development of a compiler and a single-user operating system, design of an architecture suitable for compiling and yielding a high density of code, and the development and construction of the hardware. 20 Lilith computers are now in use at ETH.A principal theme is that the requirements of software engineering influence the design of the language, and that its facilities are reflected by the architecture of the computer and the structure of the hardware. The module structure is used to exemplify this theme. That the hardware should be designed according to the programming language, instead of vice-versa, is particularly relevant in view of the trend towards VLSI technology.

Morse-code-controlled computer aid for the nonvocal quadriplegic.

Abstract: A computer-based communications system was established for a quadriplegic patient who suffered a brainstem infarction that left him with normal intelligence, but without speech and without functional motor control except for the thumb of his right hand. An arm brace was developed to support the hand and thumb so it could control two switches that generated Morse code signals. An interface was also devised to translate Morse code into ASCII characters to access a personal computer. Additional codes were added to represent keyboard control functions. This device allows the patient to communicate with others and control, to some extent, his environment.

A flexible system for microscope fluorometry served by a personal computer.

Abstract: An automated microscope fluorometer based on a modified Leitz MPV I system is described. Automation is mainly attained by the use of a cheap, commercially available personal computer system programmed in extended BASIC supplemented by a few assembly-level subroutines. The automation has resulted in simplified measuring procedures and increased measuring speed. The statistical precision is enhanced because greater cell populations can be analysed within reasonable time. Programs for several biological applications are described. Routines for cell population analysis, including storage of data on disk files, has proved especially useful. Programs for recording of corrected fluorescence emission spectra and of time-dependent fluorescence variables have also been developed. A high flexibility is achieved, as the BASIC programs can readily be modified for specific purposes. Some data on the sensitivity and reproducibility of the instrument alone, and in combination with a staining method, are also presented.

Performance evaluation: Experimental computer science at its best

Abstract: What is experimental computer science? This question has been widely discussed ever since the Feldman Report was published (1979 [18]) Many computer scientists believe that survival of their discipline is intimately linked to their ability to rejuvenate experimentation The National Science Foundation instituted the Coordinated Experimental Research Program (CERP) in 1979 to help universities set up facilities capable of supporting experimental research Other agencies of government are considering similar programs Some industrial firms are offering similar help through modest cash grants and equipment discountsWhat is experimental computer science? Surprisingly, computer scientists disagree on the answer A few believe that computer science is in flux—making a transition from theoretical to experimental science—and, hence, no operational definition is yet available Some believe that it is all the non-theoretical activities of computer science, especially those conferring “hands-on” experience Quite a few believe that it is large system development projects—ie, computer and software engineering—and they cite MIT's Multics, Berkeley's version of Bell Labs' UNIX, the ARPAnet, IBM's database System R, and Xerox's Ethernet-based personal computer network as examplesThese beliefs are wrong There are well-established standards for experimental science The field of performance evaluation meets these standards and provides examples of experimental science for the rest of the computing field

The Cell Design System

Abstract: The Cell Design System (CDS) is part of a set of tools developed in the 1970s by the Electronics Division of Xerox to support CAD design. This paper describes the CDS, which is a highly interactive graphics system used for layout of custom chips. Described are the hardware environment and language, the kinds of manipulation allowed, types of objects, and viewing options. The CDS benefitted from experience with Icarus [1] which is an early research effort for cell design layout. As with Icarus, a strong benefit of the CDS is its availability on a personal computer, thus providing a layout capability within the office confines of the designer. Also, we feel that the CDS has provided a unique and powerful method of viewing cells and has a highly effective human interface.

Personal-computer networks

Abstract: The use of small-scale computer networks is growing within the commercial environment. Establishment of thest networks not only speeds up communication, and gives greater efficiency, but also reduces costs

Device for training swimmers

Abstract: FIELD: sport ^ SUBSTANCE: claimed invention relates to sport exercise machines, namely to devices for training and improvement of motor actions, psychological stability and volitional preparation of swimmers Device contains flexible suspension rod and belt fixed on swimmer's body Rope-pulley system, drive drum is kinematically via redactor is connected with electric engine with one side, and with the other side - with travel sensor, electric engine being connected with control unit outlet and flexible suspension rod being connected in a mechanical way to rope-pulley system via spring-loaded drum, which ensures possibility of its rotation from athlete's effort and automatic return of said drum In addition, device contains personal computer, stabilised electric energy source, force sensor, pulse detector, formed by sensor, preamplifier and amplifier- HP shaper, from which force sensor and spring-loaded drum are included between rope of rope-pulley system and said flexible suspension rod, sensor of pulse detector is on athlete's body above belt, to which fixed is said rod, connected with force sensor via spring-loaded synchronous drum Rope part of rope-pulley system is made composite: larger part of its length is supporting rope, and the remaining part is pull-up rope, near which extended is multiple electric thin flexible cable, which is uncoiled and coiled synchronously on three-section drive drum, and pulse detector with USB-port of personal computer, to which also switched is travel sensor, outlet of personal computer being connected with control unit inlet ^ EFFECT: increase of device efficiency ^ 3 cl, 9 dwg

Observations on the development of an operating system

Abstract: The development of Pilot, an operating system for a personal computer, is reviewed, including a brief history and some of the problems and lessons encountered during this development. As part of understanding how Pilot and other operating systems come about, an hypothesis is presented that systems can be classified into five kinds according to the style and direction of their development, independent of their structure. A further hypothesis is presented that systems such as Pilot, and many others in widespread use, take about five to seven years to reach maturity, independent of the quality and quantity of the talent applied to their development. The pressures, constraints, and problems of producing Pilot are discussed in the context of these hypotheses.

Jericho: A professional's personal computer system

Abstract: Jericho is a reactive computing engine capable of supporting advanced high user-intensity applications systems. It has four primary architectural characteristics:1. A user-dedicated computing environment2. Direct execution of high-level programming languages3. High bandwidth communication between user and system4. High bandwidth communication between user-support machines and the other machines the task environment.Each of these architectural components will be described further, followed by a discussion of the Jericho hardware.

Management of exposure records at small businesses with a personal computer — a simple approach

Abstract: There exists a need for the safety and health directors of small businesses to manage employees' health and exposure records effectively, due to a recent OS HA recordkeeping requirement. To fulfill such a need, a simple and flexible data base design utilizing a low-cost personal computer system is discussed along with program listing and implementing instructions. Small businesses which normally cannot afford a large computer can greatly benefit from a mini-system.

An architecture for pup services on a distributed operating system

Abstract: At the University of Rochester the computer science department has had six years of experience in the design and implementation of a multiple-machine, multiple network distributed system called RIG. Rochester's Intelligent Gateway (RIG) [1,2,3] is a dual processor gateway which connects three computer networks to provide convenient access to a wide range of computer facilities. RIG was built to serve as an intermediary between the human user (working through a display terminal or personal computer) and a variety of computer systems. The bulk of the user's computational requirements is met by these systems, which are either partially integrated into the RIG system through a fast local network or loosely coupled to it through the ARPANET. RIG also provides a number of basic services such as printing, plotting, local file storage, and support for a number of display terminals.

New Ultra Low Cost CRT Controller is Ideally Suited Ton Personal Computer And Electronic Games Applications

Abstract: The ever present and expanding need for displaying visual information in such locations as banks, airports, department stores and other businesses has led to the rapid expansion of the market for information display devices. In addition, the expansion of the home computer, teletext, and electronic automotive markets will lead to a need for low-cost information display devices. Currently, the most widely used display device (where a large volume of data must be displayed simultaneously) is the CRT terminal.

How personal computers will affect the future of libraries and information centers

Abstract: The personal computer revolution will eventually change the way we receive and provide information services This will describe PRIMATE (Personal Retrieval of Information by Microcomputer and Terminal Ensemble), a personal computing system designed to help individuals index their article reprint collections With the addition of word processing software, users can prepare journal articles and other manuscripts using PRIMATE Personal computers also have broader application They could be used by special libraries for reprint collection indexing, as a terminal to a large data base, and to receive SDI services like ASCA* and ASCATOPICS® Libraries or departments could even keep subject specific citation data bases on their system Personal computers may be the missing link in the chain leading to the age of the electronic journal

Integrated Knowledge-Based Information Manipulation Systems

Abstract: The personal computer of the future will offer its user an Information Manipulation System (IMS). An IMS will allow the user to do almost all of his work (design specifications, plans, programs, documentations, reports, memos, reference notes as well as communication with others) on-line (FISCHER and LAUBSCH 1980).

JOYCE: a next generation personal computer

Abstract: This paper describes the hardware/software design decisions, cost, and development status the JOYCE personal computer. The features of the system are examined in light of scheduled applications such as CAI (a stand alone PLATO system), database management, electronic mail, and other network communication facilities. Plans for continued system development are outlined.Our experiences relating to the acquisition of the components necessary for the realization of JOYCE, including delivery delays, vendor promises, and the gap between vendor product actual operation and documented operational descriptions will be detailed.