Chapter 1: My Career Gone
Footnote: Projects during College & Employment
1963-66: Gas Lasers Interferometry: college research project using IBM1620
1966-67: Electrical Research: contacts, aerial performance, radio interference
1967-70: Flight Simulators: Douglas DC9 and Phantom F4M
1970-71: Flight Plan Processing System: for air traffic control
1971-76: Telephone Switching and Text Processing
1976-91: Freelance Projects: Technical Writing, Bespoke Software
My first introduction to computers was a course in 1964 on FORTRAN IId on an IBM 1620. This was later applied to a physics research project which used laser light to measure precise distances. The experimental set-up was as follows:
The FORTRAN program and its data had to be punched up on 80-column cards. It was then fed into the computer's card reader, compiled and run. Output was via a hammer-based typewriter.
While working for the Electrical Research Association [ERA] in 1966, I assisted with their research into the erosion of electrical contacts - particularly those of reed relays - and the nature of the high-speed electric transients produced in a circuit at the instant contact is broken.
For this work I designed and built (using experience from a previous fitting and machine-shop course in 1961) a special controlled atmosphere test apparatus. This I set up in the following experimental circuit to photograph the high-speed transients caused when the contacts broke the circuit.
I also did much work plotting the radiation pattern and gain of various aerial designs using a standard resonant dipole at various distances and directions from the test aerial as illustrated below.
As background for this work I read and greatly appreciated Max Planck's original book 'Electromagnetic Theory'. This work was of great benefit when I moved to the Redifon Flight Simulator Division where I developed software for simulating the radiation patterns of aeronautical radio-navigation aids. Over fifteen years later, I developed more sophisticated software in C to simulate aerial radiation lobes.
While at the ERA I also helped to devise methods of measuring radio interference. This involved the use of many state-of-the-art radio receivers covering the whole of the then-used radio spectrum. One of my most fascinating experiences was listening to the whistlers - the glissando sound effects produced by the radio emissions from powerful lightening strikes echoing round the globe between the ground and the ionosphere.
I spent 2½ formative years writing programs for the Honeywell DDP 124 computer at the
Flight Simulator Division in Crawley, Surrey.
It was a time of intense systems analysis and assembler programming in which I designed, developed and commissioned the simulation software for various types of aircraft navigation equipments and their terrestrial environments. My whole time at Redifon was occupied on only two flight simulators. The first was the Douglas DC9-30 civil passenger aircraft for Flight Simulators Incorporated in California. The second was the Phantom F4-M fighter-bomber for the Royal Air Force [photo]. Photograph by Richard Cooke © Central Office of Information.
Below is an overview of these flight simulators' generic hardware:
Technical Achievements: During the time I was working on these two flight simulators I either originated or significantly enhanced the following:
A test program to reproduce Lissajous figures on the large-area track recorder to test the linearity of its digital to analogue conversion and its two-axis servo motors.
The first user-friendly interface between the simulator software and the console typewriter to allow program testing using the console typewriter in place of the aircraft instrumentation so that software functions could be tested independently of the expensive aircraft instrumentation and main interface.
I did most of the systems analysis, data structuring, programming plus all the acceptance commissioning for both the Radio Navigation & Communication systems and the Inertial Platform and Flight Director systems of both these flight simulators. The software was written in DDP124 Assembler. I still have my original program listings for radio aids sections of the FSI DC9 and the Phantom F4M simulators.
System Overview: Below is a generic system diagram of the radio navigation and communications simulation software on which I worked at Redifon.
GSD: A memory file of details such as lat, long, height, frequency, Morse ident, type (omni, VOR, TACAN, ILS, DME, marker) of the NAV and COM ground stations.
SCAN: a function which does a slow scan of all ground station data to shortlist stations within a zone where stations could be receivable.
LIST: Shortlist of stations which could possibly be receivable (ie a list of pointers to relevant GSD records).
R&B: Function to compute accurate range and bearing of stations on the shortlist using the spherical geometry formulae.
SIG: Function to scale each transmitter's signal strength according to its lobe radiation patterns, eg the horizontal lobe of an ILS localiser or the vertical lobe of a runway marker beacon.
TXs: Data array of all transmitters deemed to be receivable at aircraft's current location, output signals being keyed with station Morse idents.
TUNE: Function to attenuate signal strengths of transmitters according to the receiver's tuned frequency and selectivity pass-band.
O/P: Output of signal strength, ident, distance and bearing for NAV stations and voice for COM stations + graphical representation of these for flight instructor.
Technical Achievements: During the time I was working on this radio navigation and communications simulation software I either originated or significantly enhanced the following:
Design and compilation of radio ground station databases.
Time-optimised computations of both rough (fast) and accurate (slower) range and bearing of radio ground stations.
Simulation of signal strength at a point within the 'elliptical cross-sectioned inverted oil-drop' lobe radiation pattern of a directional radio aerial.
Simulation of HF receiver's selectivity envelope by approximating to the reactance equations of multiple tuned circuits.
Software keying of radio ground station idents in Morse code.
Interfacing to NAV & COM radio controllers and tone generators, and synchro, servo, resolver and logic-driven instrumentation.
Below are the generic system diagrams of the flight director roll and pitch control channels simulation on which I worked at Redifon.
Roll Command Channel
POS1: Aircraft Position: lat, long, height, drift, pitch, roll, azimuth angles and vertical accelerations.
INS: Inertial Navigation System simulation with built-in Earth-rate Drift and Transport Wander effects.
POS2: Positional Data: lat, long, height, drift, pitch, roll, azimuth.
CCA: Compass Compensator/Adapter: takes azimuth input from compass or directional gyro and applies mag var or earth-rate drift compensation.
HDG: Corrected true heading
FDC: Flight Director Computer azimuth channel: computes the roll correction which the pilot must make to bring the aircraft on to an asymptotic intercept with the pre-set heading or radio nav station radial.
Pitch Command Channel
POS: Aircraft Position: lat, long, height, drift, pitch, roll, azimuth angles and vertical accelerations.
ALT: Radio or pressure altimeter.
HGT: Radio or pressure height.
FDC: Flight Director Computer pitch channel: computes pitch correction which pilot must make to bring aircraft on to an asymptotic intercept with the pre-set height or ILS glide slope.
Technical Achievements: During the time I was working on this inertial platform and flight director simulation software I either originated or significantly enhanced the following:
The principles of gyros and origination of the theoretical work on and the simulation of Earth-rate drift.
Simulation of the trigonometric and exponential damping functions involved in a flight director computer in order for it to direct a pilot to an asymptotic intercept of a pre-set compass heading or a prescribed radial of a radio navigation station.
Simulation of the electro-mechanical relay, electronic phase detector, operational amplifier and servo-electric motor-generator functions within an azimuthal compensator and flight director computer.
In 1970, while I was employed by Scicon, London's Air Traffic Control Centre was being automated by means of a system known as 'Mediator', the essence of which is shown below:
The part of Mediator to which I contributed was the flight plan processing system. Based on a triplicated Marconi Myriad 24bit/32k computer with two 6MB disks, this system:
accepted flight plans from airports input by data entry clerks,
allowed each flight plan to be allocated to an air traffic controller as it became active, and
displayed active flight plans to the controller and allowed him to update their progressive status via a touch-sensitive screen.
Together with the annotated radar display, this provided the air traffic controller with the information he needed to advise and instruct the aircraft captain by radio. During my work on this project, I achieved two main objectives:
Used analytical skills to sift out meaningful information from an extremely unfriendly customer requirements specification and to document them clearly in heavily illustrated personal notes which I used to give introductory lectures to new recruits to the project.
Developed and applied a unique but effective mixed diagrammatic and textual style of communicating system information from full overview to deep technical detail in a way which was rapidly and accurately digestible. This made use of both ordinary A4 manuals in conjunction with A1 and A0 size annotated dye-line diagrams.
For 5 years (August 1971 to August 1976) I worked as a technical writer for the ITT Europe Technical Publications Centre which was a case-funded service centre for technical documentation for the ITT System Houses throughout Europe (and later the eastern United States).
My first large assignment was to produce a detailed proposal for the upgrading of the TPC's automation from a simple camera copy production system based on IBM MTST composers to a computerised system covering the full document production task from creative writing to camera-ready copy. Using the most appropriate technology of the day I proposed a system, the essence of which is shown below:
In addition to the final design, I provided a phased implementation plan for the introduction to the new technology and the new working methods for the authors and camera-copy production staff. Having produced the proposal, my next task - which was as large again - was to produce a comprehensive presentation for an ITT Technical Directors' meeting in Brussels in order to market the idea to them to obtain the case funding required. This involved the production of a series of slides which could put over the essence of the system, the way it would be used, and the benefits to the ITT System as a whole in the more efficient production of better quality technical documentation. For the slides, I developed a somewhat unique illustrative style to convey this information quickly and effectively to the busy directors of this large multinational.
One of my first documentation tasks at the ITTE TPC was for the internal electronics architecture and system software of the ITT System 710 - a small voice/data communications system.
My largest software documentation job at ITTE TPC was for the software package for the Metaconta 10C Medium Local telephone exchange manufactured by the Bell Telephone Mfg Co. Antwerp, Belgium (now Alcatel Antwerp). For this I originated and developed a unique diagramming method which could show both the flow of data and the flow of control each separately and distinctly on a single diagram.
A complete representation using this diagramming method of the call processing system of the Metaconta 10C exchange was finally put together on a single diagram measuring 8 feet by 4 feet which became affectionately known as the Bayeux Tapestry. I also originated further diagrammatic methods and standards for depicting such things as the methods and techniques used for transferring control and data to and from routines on different interrupt regimes.
During 1975-76, I wrote a theoretical introduction, system description and user procedures for special traffic measurement features built into the software of the Metaconta 10C Toll Exchange. This model, which was based on stored program control cross-point technology, was built by Bell Telephone of Antwerp, Belgium to the specific requirements of the Australian Post Office. This task necessitated an exhaustive grasp of the theory and implementation of telephone traffic measurement and I made full and effective use of my mixed text + illustration style.
The main measurement was the occupancy of each subgroup of signalling devices - the exchange's main resources. This was measured for each sampling period throughout the day and presented as a histogram as shown. Exponential smoothing was applied to the successive samples to give a better feel for the daily variation.
Offered call rate and call dispersion were measured in a similar way giving the number of calls per route and the percentage dispersions of calls to down-route exchanges as illustrated in the example below:
Years later, I drew on the knowledge gained from this project when writing the traffic measurement program for an X25 network management suite.
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©Apr 1994 Robert John Morton