New Publications are available for Computer hardware
http://dl-live.theiet.org
New Publications are available now online for this publication.
Please follow the links to view the publication.A computer storage matrix using ferromagnetic thin films
http://dl-live.theiet.org/content/journals/10.1049/jbire.1960.0094
A new method for selecting a magnetic film storage element from a matrix of elements which exploits the coherent rotational mode of reversal is described. It is shown that, by using a film made of a newly developed alloy “Gyralloy I”, the reproducibility problems previously encountered can be solved. It is shown that the use of aluminium as substrate for the film enables the signal/noise ratio to be increased to an acceptable level even for very large stores; the drive power requirements are shown to be correspondingly reduced. Details are given of performance and construction of a storage device, which contains 50 words each of 50 bits.The design and applications of a general-purpose analogue computer
http://dl-live.theiet.org/content/journals/10.1049/jbire.1957.0005
The various factors influencing the design and construction of a general purpose analogue computer are considered in detail, with particular attention to the effects of finite amplifier gain, bandwidth and phase shift. It is shown that one of the most important design criteria is the gain-bandwidth product, and that the bandwidth must be much greater than is generally supposed if the computer is required to deal with lightly damped systems. A description is given of a computer designed for industrial and research applications, based on this analysis and embodying various novel features. The instrument is capable of both repetitive and “single-shot” operation, and can also deal with non-linear problems. A selection of problems chosen to illustrate the wide range of a computer of this kind is then presented. A number of little-known applications, such as the analysis of mathematical series and the construction of economic “models” are included as well as examples of more familiar uses for aircraft simulation and servomechanism design. An indication is given of the lines along which analogue computers may develop in the future, and of other possible applicationsA special-purpose analogue computer and its use in reactor engineering
http://dl-live.theiet.org/content/journals/10.1049/jbire.1961.0029
This paper deals with the description and application of a reactor analogue computer. Reactor operational and training problems suitable for analogue computer solution are dealt with and present trends in design and application indicated.Some reflections on digital computer design
http://dl-live.theiet.org/content/journals/10.1049/jbire.1960.0067
The factors influencing computing machine development, during the past decade, are reviewed from the point of view of the circuit engineer. The effect of new components such as the transistor and rectangular-loop ferrite core and of the introduction of new techniques of manufacture are considered. The reduction of the influence of the circuit engineer in computer design, is forecast due to the trend towards packaged construction and the introduction of novel concepts in design.The electronic synthesis of flexible beam behaviour
http://dl-live.theiet.org/content/journals/10.1049/jbire.1958.0017
The paper relates to the use of electronic analogue computers to evaluate and display the vibrations of flexible beams and related structures. The method is characterized by the speed and continuity with which the desired information is presented and by the fact that it provides a continous mental picture or model of the physical system being studied. The techniques described are applicable to “thin” beams in general and are capable of yielding static as well as dynamic information. They have, however, been evolved primarily to deal with problems in dynamics whose complexity makes them unsuitable for treatment by “classical” methods. A simple hypothesis concerning structural energy dissipation is discussed. It is shown to possess valuable practical advantages except where the detailed mechanism of structural energy loss is itself the subject of investigation. The essential correctness of the basic premises, and the practicability of realizing a useful synthetic “beam” have been demonstrated experimentally. Much further development remains to be completed however. The paper concludes with a review of certain directions in which progress is hoped for in the immediate future.Instrumentation at Berkeley nuclear power station
http://dl-live.theiet.org/content/journals/10.1049/jbire.1962.0002
From the shut-down power of about 10 watts upwards neutron flux instrumentation is used for reactor power measurement and to operate safety trips. At high powers, control and protection is based on temperature measurements (fuel element, channel gas, graphite etc.). Selected fuel element temperatures can shut down the reactor, others being recorded by multi-point recorders and automatic loggers. The shut-down initiating devices shut down the reactor only if at least two out of the three give a trip signal. The system of faulty fuel element detection employs an automatic logger which computes averages, giving discrimination between random and significant rises in CO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> gas activity. Equipment is also provided, for the detection of leaks between steam and CO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> circuits; in addition radiation activity in and around the station is monitored. Gas and steam flows are measured and the data transmitted by a pneumatic system. The display equipment for the major instrumentation is centralized in or near the station control room.An analogue computer for Fourier transforms
http://dl-live.theiet.org/content/journals/10.1049/jbire.1958.0022
The paper gives the basic principles of a computer for obtaining a graphical display of the Fourier transform of a function which can be represented by a finite number of ordinates over a finite range of the input variable. A delay line with linear phase-shift/frequency response is used to give the exponential term in the transform, and a time-variation of carrier frequency in sympathy with the time-base of the display unit gives the required variation of the index of this term.Data collection and distribution
http://dl-live.theiet.org/content/journals/10.1049/jbire.1962.0047
The paper outlines the evolution of data handling and processing methods employed by a group of insurance companies in day-to day operation, culminating in the adoption of a fully integrated computer system. Field trials of a telex link using live data and subsequent extension of these trials are to embrace the use of high-speed transmission equipment described. A summary of the transmission errors encountered during the later trials is given together with the approximate comparative costs of a telex and high-speed system.A method of using a general-purpose computer in an on-line time sharing application
http://dl-live.theiet.org/content/journals/10.1049/jbire.1961.0123
When a computer is coupled to a real time operation as in process control, the work load on the machine may fluctuate widely depending on operating conditions. External phenomena demanding action will occur essentially at random with respect to the machine. To cope with peak conditions the machine must be adequately fast, and thus will have idle time when activity is low. The use of time sharing techniques or more properly equipment sharing, allows the computer to utilize any idle time by having alternative jobs of lower priority, higher priority jobs having an interrupt facility on the machine. An engineering and programming method has been evolved of applying a computer to a process control system for on-line applications.Statistical computers as applied to industrial control
http://dl-live.theiet.org/content/journals/10.1049/jbire.1954.0042
The need and use of statistical methods for quality control of a continuous industrial process is discussed and some examples of quality control based on statistical techniques, but employing a “human” controller described. The advantages and disadvantages of automatizing such control from the engineering, economic and social points of view are considered. The prime functions of statistical controller are discussed. An outline of some of the circuit techniques employed is given and two practical examples are quoted—one in the bakery industry and one in cable manufacture—of the application of automatic statistical control, with histograms, etc., showing improvements effected by the apparatus.Analogue computers and their use in nuclear reactor safety studies
http://dl-live.theiet.org/content/journals/10.1049/jbire.1958.0010
Computational and circuit techniques are described which have been used successfully to study the various aspects of nuclear plant kinetics which are relevant to reactor safety. These include an examination of the overall stability of the system, the effects of coolant pump failure, burst steam lines and control rod maloperation. Particular reference is made to a revolving capacitance storage drum which simulates transport lags in coolant circuits.Magnetic film file for computer storage
http://dl-live.theiet.org/content/journals/10.1049/jbire.1960.0004
A 35-mm oxide-coated ifim store is described in which the pick-up head is out of contact with the oxide. The high quality backing medium provided by the film has resulted in complete freedom from drop outs. Interchangeability between all mechanisms has been achieved with available production heads, by using special auto-strobing circuits.The application of analogue computer techniques to the design of aero engine control systems
http://dl-live.theiet.org/content/journals/10.1049/jbire.1957.0063
The problem of aero engine control systems is shown to have reached the degree of complexity at the present time that makes it necessary to embark on analogue methods of simulation in order to predict the behaviour of the system. The parameters to be controlled are discussed and the way in which interaction may affect the individual loops is explained together with a review of the requirements of a control system from the pilot's handling, and the performance view points. As illustrations, examples of control system functional components are used to illustrate the methods of adaptation of a practical hydraulic system to analogue methods. The use of the computer results is discussed in formulating an optimum system design.A negative resistance for d.c. computers
http://dl-live.theiet.org/content/journals/10.1049/jbire.1959.0046
A d.c. negative resistance suitable for use in analogue computers is described. The circuit uses two transistors and eight resistances and is compensated against unbalance in the two transistors. A nomogram has been constructed to simplify the design of the circuit for any required value of negative resistance. There is also a discussion of the properties of, and the differences between series and shunt type of negative resistances. The circuit described gives a shunt type of negative resistance.A cathode-ray tube output for a digital computer
http://dl-live.theiet.org/content/journals/10.1049/jbire.1961.0065
The unit gives a visual display on one cathode-ray tube and has a second tube which is equipped with an automatic camera controlled directly by the computer. The device may be used for curve plotting with a resolution of 256 × 256 or for alpha-numeric display. In the latter case the computer can be programmed to display a variety of different formats and high output rates are possible.Factors influencing the applications of magnetic tape recording to digital computers
http://dl-live.theiet.org/content/journals/10.1049/jbire.1960.0002
The merit of magnetic tape for storage of digital information and the benefits of abandoning linear in favour of two-state operation are briefly discussed. Limitations on the density of recorded information are reviewed to show the extreme precision called for in the manufacture of magnetic heads and tape guidance mechanisms. Design features made necessary by high speed and acceleration requirements are considered with reference to a recently developed high performance tape handler.High speed analogue-to-digital converters
http://dl-live.theiet.org/content/journals/10.1049/jbire.1957.0042
Some control and computing problems are discussed in which advantage may be gained by encoding analogue quantities into digital form for subsequent processing. A voltage-to-digital converter has been designed for use with an electronic analogue computer in order to combine analogue and digital computation techniques. The system is basically a servo with a digital-to-voltage converter as a non-linear feedback element. A binary register, driven from a 100 kc/s clock pulse, is operated by gates arranged to allow an increasing or decreasing count, dependent on the sign of the error between the voltage input to the converter and the voltage analogue of the number in the register. Functional descriptions of the main parts of the equipment are given, with reference to some of the factors that have been found to be critical. The apparatus is now working, but experience has shown that considerable increase in both speed and accuracy is possible, and modifications which would provide this improvement are described.Logical design of a computer for business use
http://dl-live.theiet.org/content/journals/10.1049/jbire.1957.0067
The paper describes the characteristics and logical design of the E.M.I. business machine which is a serial machine operating at a clock rate of 115 kc/s using a magnetic drum for storage. The machine also has provision for magnetic tape storage and additional drum storage can be provided if required.Analogue computers in aircrew training apparatus
http://dl-live.theiet.org/content/journals/10.1049/jbire.1954.0047
After discussing the economic advantages of training on simulated equipments, some of the problems solved by the computers in flying trainers, engine trainers and track recording will be described. The relative complications of a full flight simulator computer using digital and analogue methods are considered and the analogue type found to be most suitable. The use of the building brick principle is dealt with and details of utilization, running time and percentage serviceability given. Further applications of analogue methods to training equipments are discussed.Discussion on “High speed analogue-to-digital converters”
http://dl-live.theiet.org/content/journals/10.1049/jbire.1957.0062
A high-density file drum as a computer store
http://dl-live.theiet.org/content/journals/10.1049/jbire.1960.0007
The paper describes a large-capacity magnetic drum store having a capacity of ̃ 15,000,000 bits and an average random access time of ̃ 200 millisec. A packing density of just over 1,000 bits per in. has been obtained by floating specially designed heads on a film of oil which automatically maintains a spacing of 0.002 in. between the head and the drum surface. Special considerations led to the use of a copper-nickel-iron alloy for the drum surface. A self-clocked reading system is used to obviate the need for high mechanical stability. The reading circuit also has special features which keep it operating under optimum conditions over a range of signal amplitudes.Electronic simulation and computer techniques in the design of automatic control systems
http://dl-live.theiet.org/content/journals/10.1049/jbire.1961.0042
Computing techniques for the development of aircraft automatic control systems are described which commence with a completely theoretical investigation on an analogue computer, thence by the introduction of more and more actual components to a complete simulator. Preliminary component specifications are ascertained for any given overall system characteristics. The testing of components which have been developed for use in the actual system is carried out to check the final characteristics of the system. Techniques which have been developed for the inclusion of complex mechanical loads in such simulators, and also the part played by the human operator in a control system are described. The idea of a computer which is capable of automatically setting its own coefficients (i.e. system parameters) so as to give an optimized overall system response is discussed briefly.Electronic analogue computer simulation of multi-machine power-system networks
http://dl-live.theiet.org/content/journals/10.1049/pi-a.1962.0095
The paper describes how a general-purpose electronic analogue computer may be used to simulate multi-machine power-system networks. The transformation of the individual components of the system into a common reference frame is described, together with the derivation of the necessary transformations between rotor reference axes. A four-machine system is used as an example of the method.A short review of read-only memories
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1963.0025
Ace storage drum
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0331
Discussion on “An accurate electroluminescent graphical-output unit for a digital computer” before the Measurement and Control Section, 5th November, 1957
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1958.0270
Mercury: a high-speed digital computer
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0039
Details are given of the design and construction of a new universal high-speed serial digital computer with a digit repetition frequency of 1 Mc/s.Logical differences between the production machine, called ‘Mercury’ and its prototype, which was built at Manchester University, are discussed in some detail.The constructional techniques adopted for the electronic equipment are described and reasons are given for their adoption in terms of accessibility and ease of cooling.A detailed order code is appended.The mercury-delay-line storage system of the Ace Pilot Model electronic computer
http://dl-live.theiet.org/content/journals/10.1049/jiee-2.1953.0184
BESM computer of the U.S.S.R.
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0327
Store used in Pegasus
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0333
Application of digital computers in the exploration of functional relationships
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0020
In order to discover the optimum process conditions and to supply basic data for process control, it is necessary to determine, at least approximately, the process lawη=f(ξ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sub>…ξ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/"><i>k</i></sub>;Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sub>…Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/"><i>p</i></sub>) ….(1)connecting a response η (such as yield of product) with levels of the variables ξ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sub>…ξ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/"><i>k</i></sub>(such as temperature, time, pressure, etc.),Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sub>…Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/"><i>p</i></sub> being unknown parameters.The problem is discussed of using an electronic digital computer for fitting the function eqn. (1), to a set of observed data,(<i xmlns="http://pub2web.metastore.ingenta.com/ns/">a</i>) when the functional form is unknown but can be locally represented by a multivariate polynomial, and(<i xmlns="http://pub2web.metastore.ingenta.com/ns/">b</i>) when the functional form is not known explicitly, but is thought to be the solution of <i xmlns="http://pub2web.metastore.ingenta.com/ns/">s</i> simultaneous differential equations.In case (<i xmlns="http://pub2web.metastore.ingenta.com/ns/">b</i>), starting with any guessed values of the parameters Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">1</sub>…Θ<sub xmlns="http://pub2web.metastore.ingenta.com/ns/"><i>p</i></sub> the electronic computer is caused to follow a series of trial values which result in progressively smaller discrepancies between observed and calculated values of η. The procedure provides the least-squares estimates of the parameters and their standard errors; it also gives a criterion from which the adequacy of the form of the assumed sets of differential equations may be judged.An example of the application of the method is described.Deuce
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0235
The programming strategy used with the Manchester University Mark I computer
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0034
The paper gives an account of the programming strategy developed for use with the University of Manchester electronic computer Mark I, a typical 2-level storage machine of which a brief description is included. The topics dealt with include: the method of storing and calling in routines; the representation of instructions outside the machine (tracing the reasons for the use of a teleprint or scale-of-32 code); the organization of the library of sub-routines; the mechanism of interpretive routines for double-length and floating-point operations; matrix operations; partial differential equations; an attempt at automatic programming; mistake diagnosis in programmes; and measures for dealing with machine breakdown. Finally, the basis of the strategy is considered in relation to the Mark II machine.The use of analogue computers in predicting the space-time behaviour of nuclear reactors
http://dl-live.theiet.org/content/journals/10.1049/pi-a.1962.0087
The study of the dynamic behaviour of a complex system such as a nuclear reactor is conveniently performed on an analogue computer. The equations to be solved are described, and three approximations suitable in different circumstances are given. The application of one of these methods to an investigation of spatial instabilities is presented.The HEC computer
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0046
The HEC4E computing machine was designed specifically for application to commercial calculations.It is an electronic digital machine of medium size functioning in the serial binary mode, the pulse repetition frequency being 40 kc/s and the word length 40 binary digits. The main storage for both numbers and instructions is a magnetic drum having 64 tracks each holding 16 words.Besides being able to perform all four arithmetic functions automatically, the machine has facilities for the automatic conversion to and from the binary scale for any normally used scale of notation.The input is by means of standard punched cards, and both a printing mechanism and a card punch are provided for the output of results. The machine is constructed in four physical units: the elec tronic unit, containing approximately 1100 thermionic valves; the operating console, providing manual controls and a visual display of the course of calculation; the tabulator providing both punched card input facilities and the printed output; and the card-punching output mechanism.Analogue investigation of a graphite power reactor
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1963.0086
An article based on a paper with the full title <i xmlns="http://pub2web.metastore.ingenta.com/ns/">‘Analogueinvestigation of the stability of a graphite power reactor’</i>,which is published this month in the Proceedings. The paperwill be read at a meeting of the Science and General Divisionon the 5th March 1963 at Savoy Place.Deuce: a high-speed general-purpose computer
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0038
Deuce is a high-speed general-purpose binary digital computer, operating throughout in the serial mode at a digit frequency of 1 Mc/s, and using mercury delay lines as its primary storage system. It is a development from the Ace Pilot Model, which was developed by the National Physical Laboratory and has had an outstandingly successful career since it was commissioned in 1952. Many features of Deuce are common to this earlier machine, but a number of operational improvements have been made, together with additional features to facilitate maintenance and also to reduce the problems of testing new programmes.Input to and output from the computer are by means of high-speed punched-card machines, and a large-capacity (8192 words) magneticdrum store augments the main mercury-delay-line storage system.The internal organization of the machine is discussed, followed by a more detailed account of some of the novel features incorporated. Other sections describe briefly the construction of the machine and refer to typical applications.A basic transistor circuit for the construction of digital-computing systems
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1958.0283
There is a large field of application of digital-computing techniques where reliability and simplicity are far more important than speed. A basic circuit is described which uses one transistor, one capacitor and three resistors, from which a complete digital-computing system may be constructed economically. A system using this circuit is extremely simple to design, construct and maintain, and should prove very reliable, although it cannot achieve the speed of operation of systems using more complex circuits. The way in which well-known computer circuits are constructed from this basic circuit is described, and an account is given of a complete logical system, employing 184 such circuits, which was constructed to demonstrate their application.The magnetic storage drum on the Ace Pilot Model
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0103
This magnetic drum is used as a medium-speed store in conjunction with a high-speed mercury delay-line store in a serial computer. 262,144 binary digits are stored on 256 tracks, each storing 32 words of 32 binary digits. Information is transferred either to or from a mercury delay line in blocks of 1024 digits, each transfer taking about 12 millisec. The reading and writing heads can be moved axially along the surface of the drum so that each of the 16 pairs of heads has access to 16 tracks.Discussion on “The digital computer applied to the design of large power transformers”
http://dl-live.theiet.org/content/journals/10.1049/pi-a.1959.0090
Discussion on “The design of housing-estate distribution systems using a digital computer” before the South Midland Supply and Utilization Group, at Birmingham, 9th October, 1961
http://dl-live.theiet.org/content/journals/10.1049/pi-a.1962.0152
Aids in the calculation of transient stability
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1962.0120
New high-speed digital technique
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1959.0011
A new high-speed digital technique for computer use
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1959.0394
A new method is described for realizing logical functions using square-loop ferrite cores and transistors. Complex circuits can be built up from identical elements, each consisting of one core, one transistor, three diodes and one resistor. The technique differs from earlier methods in that the current required to set a core to the ‘1’ state is derived from a common supply and not from a previous stage.The control of digit transfer between stages is effected by a transistor whose collector and emitter are connected across one winding of the core. When a ‘1’ is to be set in the core, the transistor is arranged to appear as an open-circuit, in which condition flux reversal is possible; when a ‘0’ is to be set, the transistor appears as a short-circuit preventing reversal of flux.The core is reset to ‘0’ at a controlled rate, producing a standardized voltage across the output windings. Logical operations are carried out by the analogue addition of these voltages. The system requires only two low-voltage d.c. supplies and is tolerant of voltage and component variations. It operates reliably at digit rates of 500kc/s. The paper also describes an experimental application of the method, designed to test its performance.Traction problems
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0196
Short-cut multiplication and division in automatic binary digital computers, with special reference to a new multiplication process
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1958.0332
The paper considers the application of analogues of the well-known decimal short-cut multiplication and division methods, to the control of such operations in automatic binary digital computers.After demonstrating that the simple binary short-cut process leads, on the average, to a slowing down of multiplication, the paper developes a new process, termed the modified-short-cut (m.s.c.) process. This is defined in terms of symbolic equations and is shown to reduce the average number of additions or subtractions required during the execution of a multiplication by more than 17% to some <i xmlns="http://pub2web.metastore.ingenta.com/ns/">m</i>/3 (for an <i xmlns="http://pub2web.metastore.ingenta.com/ns/">m</i>-bit number), the maximum number by nearly 50% to (<i xmlns="http://pub2web.metastore.ingenta.com/ns/">m</i>+2)/2 and the average number of shifts by 30%.Following a discussion of the properties of the process, and, in particular, its application to signed multiplication, comparisons are made between the relative average multiplication times of a number of alternative systems including those using circuits based on ‘carry’ storage or on carry-propagation-detection circuits, or on both.Brief consideration is then given to some aspects of division in automatic binary machines. The discussion is confined to a consideration of what are believed to be ideas not previously published. It is shown, in particular, that short-cut procedures can be easily and cheaply incorporated in machines using either restoring or non-restoring division techniques.Computer operations required for mechanical translation
http://dl-live.theiet.org/content/journals/10.1049/pi-b-1.1956.0094
Exploration of functional relationships
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1956.0199
Analogue computer for coal-flow simulation
http://dl-live.theiet.org/content/journals/10.1049/jiee-3.1961.0025
Magnetic film storage units
http://dl-live.theiet.org/content/journals/10.1049/pi-b-2.1962.0032
The thin magnetic film has now become a very attractive addition to the ferrite toroid and plate matrix as storage and switching elements in digital computers. Five types of film unit are being investigated:Nickel-iron vacuum evaporated on insulating and conducting substrates.Nickel-iron electrochemically deposited on conducting substrates.Nickel-cobalt chemically deposited on insulating substrates.Nickel-iron deposited by cathodic sputtering on insulating substrates.Ferrite films on insulating substrates or self-supporting.Of these, the first has been the most extensively examined. The rest are alternatives attempted as possible improvements over the first type. Advantages offered by thin-film storage units are small size, small power required for switching and very high switching speeds. The main disadvantage is the small Output signal of the film, making the design of sensing amplifiers used in the computer circuit more critical.