Making images with computers is essentially a process of calculating, storing in memory and displaying an image derived from some sort of application data. The constraints have always been how much data can you display in any one period (especially if making animations for example) and this depends on the storage capacity and speed of the memory and the characteristics of the display. After the Jacquard loom, used for weaving what were in effect still images from data stored in punched-cards,1 the Williams-Kilburn tube electrostatic store or memory, which made the first stored-program computer possible,2 is perhaps the prime development for the production of graphics by computer.
The CRT store was the means of storage itself, but it was also possible to understand the CRT as a map of the states of the bits in memory.Since it is maintained in an enclosed metal box with a special detector across the face of the tube, the memory array cannot actually be seen, however, by tapping-off the memory regeneration circuits that map could be displayed on another CRT and used to monitor the state of the machine. This diagnostic function was, for a long time,the main use of the CRT displays which accompanied many of the early machines (and in particular the first machines in Australia).3 [Figs.11 & 12]
However it was also recognised that the CRT store could do “fun” things like make announcements in text characters running across it or play games and it was eventually possible to use the CRT display dedicated to monitoring memory to produce actual useful displays of data results.
Australia’s first computer was the CSIR Mk1 built between 1947 and 1951 in the Division of Radiophysics of the CSIRO and it became known as CSIRAC after it was moved to the University of Melbourne in 1956. Its development and structure is covered in.4
CRT displays were an important part of CSIRAC diagnostics and their use was extended when the switch panel used to start up the machine was incorporated into a proper desk console5 with six 2-inch (50 mm) diameter CRT displays offering monitoring of the arithmetic registers, the current contents of memory.6 It also had a “Flexowriter” character printer for printing out program results.
With CSIRAC, although there was very little use of the CRTs or of the “Flexowriter” line printer for graphics they could certainly produce images, and, in Ditmar (Dick) Jenssen’s research work(below), we will see the results of at least one use in which the results of calculations were presented as 2-dimensional data like a graph or a “map”, in a manner that was as much an extension of graphing techniques in science as it was an extension of the computer printout.
During public demonstrations CSIRAC would be used to play games, programmed by Jenssen, which included a guessing game he called Telepathy, a Calendar game (which printed out the day of the date you entered onthe console switches), and NIM (a “matchstick” game based on“pick-up-sticks”).7 [Fig.13] Images, per se, had to be prepared directly from the results data, either by direct placement of bits into appropriate locations in memory if a CRT display was desired, or by direct placement of characters into the appropriate rows and columns of the printed page via the Flexowriter. Each of these activities would take large amounts of computer time which, in this era, was a rare and valuable commodity, so graphical use of the computer was usually discouraged.
CSIRAC was both a research and a teaching machine. As some of the students using it became more competent with it, night shifts were made available and it was during this time that it was used to do some of the first significant computer generated graphic data visualisation in Australia. These resulted from an investigation into numerical weather forecasting by Jenssen. He was first introduced to CSIRAC on a programming course at Melbourne University in December 1956, and then proceeded to do a Master’s thesis in numerical weather forecasting, building a model for predicting the weather 24 hours ahead from the current day’s weather data. His early successful attempts to do numerical weather forecasting rated a mention in the [Melbourne] Sun, Mon, Sept.22, 1958.8 The calculations were done on CSIRAC and the results were output to punched paper-tape.9 Then, again using CSIRAC, the results could either be displayed on the Memory CRT or, off-line, printed out on the Flexo-writer.
In his Masters thesis10 there is a single composite photograph of the CRT screen, with an outline map of Australia superimposed on it. Essentially the image shows alternating bands of atmospheric pressure as contours with each band covering a range of, say, 10 millibars of pressure difference. The pair of images in Fig.14 are from Jenssen’s PhD thesis,11 but the left image is essentially the same image as in the MSc thesis dated 1959. It shows a memory display of the initial pressure field and the right image shows the 24-hour forecast. The initial data are from a Weather Bureau 5000-millibar chart.12 Alternating pressure bands are shown by “on” and “off” bits.
The image was printed from a photograph of the D-register13 CRT. The map was hand drawn onto the print, then re-photographed. The composite photos were made early in 1957 by Melbourne University Audio-Visual Services and are primitive bitmaps with the resolution limited to 20 dots by 16 lines by the size of the registers that held the data. Referring back to Fig.13 of the word NIM in the D-register of CSIRAC, we can see that it, too, was made up of 16 rows each of 20 bits with the appropriate bits turned on to make up the large characters (there are two blank rows above and one bank row below the characters). The program to do this character display is essentially the same as the one Jenssen used to show the barotropic data.
The barotropic CRT image was one of the first things Jenssen did on CSIRAC; it was simply a matter of placing a twenty bit number with appropriate bits set high or low into each of the 16 D-registers and was a very quick routine that functioned as much as a check to see that the data had been punched in correctly. He commented that the impetus for him to do the contours as bits on the D-register raster came from being dissatisfied with the detail that the Charney et al paper could provide.14
As one can see, the resolution of the images made possible with CSIRAC’s monitoring displays was not very good, but this is what the structure of the computer permitted. To achieve better resolution the solution was to print out the results as an array of characters on a page of paper with the Flexowriter. Fig.15 shows the use of “full stop” characters placed at appropriate columns over the rows of printout so that an indication of the continuous lines representing the contour boundaries of atmospheric pressure could be given. Again the outline maps are hand drawn onto the printed contours.
In his PhD work, data were calculated on UTECOM (at the then Kensington Institute of Technology, NSW; now the University of NSW) in 1960, and the numbers again output to punched paper-tape. Jenssen would then bring the paper-tapes back to Melbourne where the results could be checked. To make the contour map images the punched-tapes were printed on the Flexowriter. Fig.16 shows a Flexowriter printout also using character arrays but this time using numeric characters to mark the contour bands of increasing atmospheric pressure. As before the maps are hand drawn onto the printout. Jensen commented that he created the images in this way from a desire to reproduce the published weather maps, which were drawn by hand from computer generated data.15
In making the CRT images, CSIRAC was being used as an off-line graphics device rather than the calculator it was originally intended as, but this foreshadows the direction that computing would take over the next decade as more and more tasks were distributed over a collection (soon to be a network) of machines. Jenssen acted both as the researcher of the meteorological data and the technical developer of the graphic displays, which he generalised into the game images. Essentially what he wrote for the CSIRAC was a plotting program.
Jenssen also produced some computer music on UTECOM while doing the calculations for his barotropic forecasting model (off-and-on between 1959 and 1962). He arranged his program so that the value from the data entered into each iteration of the calculation would send a related number of pulses to the computer’s speaker as it ran through each cycle of the loops of varying length that went into the calculation process,producing a sequence of tones that were determined by the data values used in calculating the barotropic contours. He called it “Barotropic Rock” and told me that the regular sound had quite a rhythmic effect.16 Sadly there is no recording of it, but in the late 1950s that would have been very difficult.
Overall, CSIRAC did a lot of valuable work but eventually it was just too old and too slow to be useful anymore.17 In the meantime two new computers had been established at universities in Sydney. One was the UTECOM, an English Electric Deuce machine18 at the then University of Technology (now UNSW), and the other was the SILLIAC, established at the School of Physics in the University of Sydney, which was a descendent of John von Neumann’s Institute of Advanced Studies (Princeton) machine. As I have not been able to gain all that much information about the UTECOM, I am not going to follow it up here.19 However it was supplied with a Tic-Tac-Toe program which set the play grid up on one of the pair of monitoring CRTs on its console.[Fig.17]
SILLIAC’s construction and early use has bee discussed in Australia’s First Computers: SILLIAC. It was the site of what was an extraordinarily open and productive collaborative environment in the University of Sydney which initiated the computer industry in Australia. Also the foundations of computer art and computer graphics in its many manifestations were laid around it.20
SILLIAC was equipped with a CRT, set up as a monitoring display, which had a 40-way switch by which the operator could select one of the forty bits from each of the 1024 (1K) 40-bit words of (Williams-Kilburn tube electrostatic store) memory.21 The monitoring CRT was mainly used to gauge the progress of a program through the computer by watching for repetitive behaviour in the pattern displayed on a 32 x 32 dot “raster” (grid) of the CRT. In Fig.18 Chris Wallace is seen closely monitoring the CRT as his program runs. The blinking on and off of the dots on the display represented the contents of memory as it changed over the progress of the program. Iterations would give regular repeating patterns on the screen, [numbers (variables) could be seen to be growing or decaying,] and “bugs” could be noted when the pattern went into an unexpected repetition if the program got “stuck in a loop”. The CRT was also used for games and could display alpha-numeric characters by stuffing high or low bits into the appropriate memory locations, in the same way that Jenssen had been doing with the CSIRAC (and see the SILLIAC program “Drawing Pictures on the CRT”, below). Later in the 60’s when the machine was made available to honours students it was used for animations.
Along with the monitoring CRT, SILLIAC had a loudspeaker that was used to follow the progress of a program but could also be used to play music. Several music programs including “Happy Birthday” and “Yankee Doodle Dandy”came with the program library received from the University of Illinois. McCaughan describes them as sounding “vaguely like bagpipes”.22 A number of other music programs were written over its years of operation by Chris Wallace, Bob Donnelly, David Jacques and Jenny Edwards. McCaughan, who was a tape recording enthusiast, made a recording of the diagnostic program “Leapfrog” running through its cycles in about 1964. He recalls:
“It also had an engineering test routine called “leap frog” which played through the loudspeaker a sequence of notes that was repeated with variations that grew more complex. It was definitely harmonious, but rather eerie. TV viewers from the early sixties might remember a sci-fi series called A for Andromeda that had computer music for its theme not unlike that of SILLIAC.”23
The machine also had a character-printer (Teletype) which was used for printing out the results of programs and calculations. Mostly the data printed with the teletype was then taken out of the computation lab by the user and, if graphical results were needed they were hand plotted to graph paper. The machine could also be used to compile tables from which the teletype could print the results in formatted columns. There were a great range of applications for SILLIAC, though the important ones from the beginning were in studies of nuclear physics and cosmic rays, followed by radio astronomy and crystallography.
Cosmic Ray research
The Cosmic Ray Air Shower project was conducted partly by gathering data from an array of 92 Geiger Counters spread out in five rows, 3 meters apart, on the lawn behind the School of Physics building. [Fig.19] The output of the counters was automatically recorded to punched paper-tape for input to SILLIAC.24 One of the research projects using data from this array was to study the variations in the times that a shower would trigger the Geiger counters. Careful study of this data could then reveal the direction from which the core particle that triggered the shower had come.
Part of this work was presented in Peter Poole’s Ph.D. Thesis.25 In that work there is a series of printouts that show the Geiger counter array as a set of dots, numbers and Xs in a grid over the page giving a direct visual description of where the triggering events, and the number of them per Geiger detector, had occurred in any one particular shower. [Fig.20]
Because they took up too much computer time to print directly, the line printer graphics were punched to paper-tape from the computer and then printed out“off-line” on the Flexo-writer. This is a very early scientific visualisation of the data sources produced through the character-printer output technique of placing printer characters in the appropriate places on the page.The original versions of these printouts were probably made around1959.26
This technique for representing data as a graphical display is very similar to the technique of printing banners that became, for many people their first contact with what computers could do in general as well as in graphics. The procedure for printing banners is important and uses a similar technique to that which Jenssen employed in his weather forecast printouts done in 1957 using CSIRAC as well as Poole’s Geiger counter map, just mentioned. A large character font printout can be made by printing a single character (often an “X”) regularly across the columns of the page. When printed line-by-line down the page, these rows of characters would make up characters(read along the length of the page) or other graphical objects (like the University’s coat-of-arms seen in the KDF9 banner, Fig.24, below) that take advantage of our ability to, at a distance, see patterns in things that when seen close up are a mass of detail.
Another of the major research areas in which SILLIAC was used was crystallography. These studies were initially run by Hans Freeman of the Chemistry Department at the University of Sydney and later by his students including John Lambert-Smith and Mitchell Guss. The main use of the computer in this work was in the calculations involved in the Fourier syntheses which help determine where the atoms in a crystal plane lie on the basis of data gained from the diffraction, by electrons surrounding those atoms, of x-rays beamed at the crystal. These calculations generated much data and initially had to be hand-plotted to see the arrangement of atoms arrayed over the cleavage planes (the faces) of the crystal structure.27 Obviously this suggested that the use of a computer to analyse the data would help greatly.
One of the first moves was to produce a graphical representation of the 2-dimensional array of X-ray intensities diffracted through one plane of the crystal. In 1963 a program was written for SILLIAC that would represent the numbers produced as a 64 x 64 array of characters in a printout, with successive alphabetical characters representing the amplitudes of the intensity values gained from the x-rays deflected off the atoms in the crystal planes.xxviii The program was used “to convert standard numerical output tapes into a coded alphabetical form.” It yielded “a rectangular array of alphabetical characters, each number being represented by a single alphabetical character. The sequence of letters, A to Z, are equivalent to numerical values of decreasing amplitude” and produced an array of up to 64 characters per line, on a line-by-line basis.29 Unfortunately there appear to be no extant examples of this kind of printout, however it was from this kind of work that the contour diagrams of electron density were then developed. Nevertheless, it might have looked a bit like the drawing in Fig.21. We can see that this type of printout foreshadows the need for a plotter to be utilised in the production of contour drawings of relative values of an array of data.
Another program written for the machine was a Raster Contour Plotter.30 This program allowed the user to display, on the 32 x 32 spot raster(grid) of the monitoring CRT, a contour map of the comparative values of any set of data in two variables (ie, two dimensions) that might be entered into, or produced with, the machine.31 The contour plot would be iterated over a range of 20 values for the desired spread between contours so that the user could select the most satisfactory version for their purposes. Once the user had the best version of the contour pattern they could get from this process, they could print it out on the line printer using the by now standard approach of letting characters represent points in the image.
The print “routine will print out a pattern of zeros and spaces as printed by the teletype equipment,corresponding to any of the twenty patterns appearing on the raster. It does this by printing a zero where there was a dot on the monitor screen and a space where there was no dot.”32
Program Q5 could have been very useful for crystallography in which a two-dimensional projection of the disposition of the atoms in any particular cleavage plane of the crystal could be displayed, however I do not know whether it was ever used by them. The other possibility is that it was written to help the Radio-astronomers but I haven’t been able to find out whether they used it either. The Radio-astronomers in the School of Physics used the plotter to map their radio data onto photographs from optical telescopes so that they could identify the visible (or not) sources of their signals.
It was also possible to display large characters on the monitoring CRT as patterns of bright spots on the raster. This was done at the dedication ceremony in1956, but, at present, I have no information on precisely how. Nevertheless, a good indication is available in the SILLIAC program “Drawing Pictures on the CRT” of 17th September 1963. The program description says:
“This program draws a picture on the CRT given by the first 32 bits of the data words. The level at which the picture is to start and the relative level at which it is to end must be given as sexadecimal33 digits.”
Thus by inputting the appropriate number – in which the first 32 bits of the binary value of the number represents the spots that had to be “on” (bright)or “off” (dark) – into the machine in the order that they should appear down the raster, a picture or a character of the required height could be produced. See Fig.22 for an example of the output of the routine.24
By 1961, Silliac was becoming overloaded with work and a SILLIAC II was mooted, however its development costs rose too far and in 1962 it was announced that an English Electric KDF9 would be its replacement. The KDF9 was commissioned in April 1964 by the Governor General Lord De L’Isle. [Fig.23] A banner was printed out, using the technique of placing characters in appropriate places on the paper, with the coat of arms of the University, the Governor General’s coat of arms and the announcement of the computer’s thanks. [Fig.24]
SILLIAC was retained until 1968. It was simulated on the KDF9, which became the preferred machine to do the type of work originally done on SILLIAC.35 It turned out that SILLIAC had a much better magnetic tape handling arrangement than the KDF9 so Wallace designed a fast communications link between the two machines that meant that SILLIAC could now be seen by the KDF9 as a peripheral. This was the first step in developing one of the earliest local area networks in the world. In 1967 IBM donated an IBM-704036 with a 1401 front-end to the department, which was followed up with a CDC-170037 and a DEC-PDP8 mini-computer38 which was purchased for graphics display.
All the machines were linked up [see Fig.26] and at the International Federation for Information Processing (IFIP) conference in Edinburgh, Scotland, in 1968, Bennett and Wallace reported on this new development and the idea of distributing functions over several processors that allowed the load to be shared across machines with different capabilities.39
This series of developments in the computing capabilities of the Basser Department are of crucial importance to the development of a computer graphics industry in Australia. Suddenly the capacity to send data to a dedicated graphics processor (here the PDP-8) became available, and it was not at all long before it was in use (in the Aeronautical Engineering project we shall introduce in the next section). But it wasn’t just hardware that made all this happen. The other crucial element was the interest of Bennett, the head of the department, which had been piqued by Donald Brook of the University of Sydney’s Fine Arts Department. Bennett also visited the Cybernetic Serendipity exhibition in London just after the IFIP conference in Edinburgh.
After the KDF-9 became established at Basser, SILLIAC was given over more to teaching and post-graduate research. The students had charge of the machine and, among much useful research, produced lots of music and some animations. One of these latter has become legendary among staff and students of the period. This was what became known as the “Peeing Man”. [Fig. 25]
When discussing the use of SILLIAC with David Jacques (who had been an honours student in the Basser Department), he explained how they started up SILLIAC every morning. He would go into the power supply room and switch on each of the supplies in sequence, then they would wait for about half an hour while the supplies stabilised, before running the system diagnostics routine that would confirm that everything was running okay. This was the “leapfrog” program or some other program that tested all the various hardware functions of the machine. But the students and some of the staff produced a variety of “fun” programs, including the music programs and a variety of animation “programs to make little stick figures move around the raster screen”40 to do the daily system test. The “peeing man” was one of these, and it would be attached to the start-up program when occasion deserved, usually when a visitor was to be shown the machine.41
It took some time to discover what this animation actually looked like and it was not until, while enquiring by email of other users of the machine, that June Crawford, who had been a programmer on the machine gave me a description that she considers (memory being what it is) to have been probably what it looked like.
She relates how she and Bob Donnelly, who was the Computing Laboratory Manager at the time, made the peeing man animation.
“It was one of those fun things where we bounced ideas off each other until we finally settled on the design – I guess it was designed to shock people. Bob and I translated the ‘picture’ into bit patterns and then David[Crawford] came along and the three of us (I don’t honestly think anyone person can be held responsible) thought up the idea of the emptying of the body (David if anybody contributed this notion). Bob and I thought of just turning the switch to show the picture on the raster, but David said he could program the animation and did so.
I have attached a picture which I think is very close to the original, though if you ever find Bob Donnelly … he might have a different idea – memory is a strange thing. The animation involved ‘emptying’ the body, and filling up a couple of rows on the ‘ground’. The space (a few rows)underneath the picture held the program, which was of course also a collection of ‘dots’.”42
June Crawford’s suggestion is shown in Fig.25
I did find Bob Donnelly and his comment was that her drawing was pretty accurate.43 The “peeing man” program was a “brute-force” program that simply wrote directly into memory locations as required by the sequence for drawing the outline of a man on the CRT.44 David Jacques described the animation: The outline man would then raise his hand to his mouth as though drinking and the outline would fill up from the feet up. When he had filled up completely he would then lower his hand and pee out the entire filling, emptying from the head down to the feet.45 David Crawford then animated the basic drawing:
“My contribution was to animate it by shifting the bit patterns in memory. It was basically a stand alone program but it was not unheard of to splice the program into one of the standard DOI (Decimal order input) programs that were first loaded to read the user’s program. This was usually done to someone who was a bit uptight and we made sure there was an audience. There were several other picture programs but I cannot recall any details”.46
The important thing about the monitoring CRT and its relationship to the memory was that it was a direct copy of the state of a single bit (say, bit 1) in each of the 40 Williams tube stores. As such, it displayed memory as a bit-map in a grid or raster of 32 x 32 dots in a square on its screen. By setting the appropriate bits in memory a crude image could be produced and this was how the “stick figure” animations were done. This is the same concept as had been employed in the program “Drawing Pictures on the CRT” (above). It was also the same idea (though with a different class of memory device) as used by Ditmar Jenssen in his weather maps produced in 1957 on CSIRAC and it is not dissimilar to the Raster Contour Plotter program that could well have been used in the development of x-ray crystallography (as foreshadowed by Pearcey way back in 195147) though I have no evidence that it ever was. With Crawford’s version, loading high or low bits into each location in memory in sequence meant that the bit map could be changed as fast as the memory access cycle would allow, and this is how animation became possible.
Then in 1968 SILLIAC was decommissioned. David Jacques and Jenny Edwards programmed versions of the Funeral March by Chopin which it played and, as the Vice Chancellor switched SILLIAC off for the last time, he proclaimed “SILLIAC I commit you to the deep.” A long and remarkable career was over.
The Basser system was augmented over the 1960s with the inclusion of a CDC-1700 as the hub for a network of terminals and a PDP8 for experimenting with graphics, as well as a IBM 7040 machine for the scientific calculation tasks of the Department. [Fig.26] The most important aspects of the system for my purposes here are the PDP8 and its use as a graphics terminal and to a lesser extent the use of the KDF9 to produce plotter images. We will come to this in the next chapter.
In the meantime, I have introduced two forms of graphics presentation that were in a primitive stage during the use of these two early machines. I now want to provide a more detailed background on the technologies that were used to present graphical output, covering graphics produced with the printer and the plotter and then looking in more detail at the primary electronic means of display, the various forms of cathode-ray tube.
1 Babbage, 1864, op cit.
2 Lavington, 1998, op cit; Deane, 1999, op cit.
3 On these early machines programming was always done in the direct code of the hardware of the machine (no assemblers, compilers or high-level languages yet) and debugging a program involved the difficult process of ascertaining where the machine had stopped or whether it was stuck in a loop. The monitoring CRT could be very helpful in diagnosing the state of the machine if a bug arose, which often happened (and may well have been either a hardware failure or a software problem). The beginnings of computer music lie in this diagnostic function as well. Many of the early machines had a speaker attached to the machine occupying some convenient memory address location so that a bit could be programmed to make a noise through the speaker. If the speaker then stopped you knew the program had stopped or if it went into a repeating loop of the same sequence of sound then the machine was in a loop in the program. This was also exploited by some early users to make sounds that were simply entertaining but based on the behaviour of the program while it was engaged in processing the data of their task, for example, Ditmar Jenssen’s Barotropic Rock.
4 Deane, John (1997) CSIRAC Australia’s First Computer, Killara, NSW: The Australian Computer Museum Society; McCann, D. & Thorne P. (eds.) (2000) The Last of the First. CSIRAC: Australia’s First Computer, Melbourne, Vic.: University of Melbourne, Dept of Computer Science and Software Engineering.
5 It is difficult to know when this occurred but the CSIRO Annual Report for June 30, 1952 mentions the intention to build a control desk in the next year, 1952-53. It was probably later not earlier.
“Nim” used the D-registers as a display for the “piles of matches” involved, and “Telepathy” used the front panel light display of CSIRAC. “Day of the week” was a simple teleprinter printout. [from an email from Jenssen dated 24 May 2001.]
The electronic version of the game NIM was originally implemented as a popular demonstration of what computers were on a specially constructed machine at Ferranti in Manchester for the 1951 Festival of Britain. The idea for the machine was suggested by John Bennett, an Australian, who led the Ferranti Mark I* programming group. [see Bennett, J.M., “Autobiographical Snippets”, p.55, in Bennett, et al, 1994.] Bennett returned to Australia in 1956 and is of fundamental importance to our story. [see the section on SILLIAC]
8 Lyell, Peter (1958) “We will never be sure” The Sun, Monday, September 22, 1958, p.6. Melbourne.
9 Jensen’s work was prompted by a 1950 paper by Charney, Fjortoft and von Neumann [Charney, et al, 1950] which produced the first weather forecast from actual weather information. It included a printout of the barotropic contours (what we think of as “isobars”) as filled-in blocks. The equations of barotropic vorticity (defined as the spin of an atmospheric element as seen by an observer on the Earth’s surface) that Charney, et al, used were known to produce correct results in forecasting but nobody could prove why. Jensen showed why the barotropic model actually worked in his MSc thesis [Jenssen, 1959].
10 Jenssen, Ditmar (1959), On Numerical Forecasting with the Barotropic Model, MSc thesis: Meteorology Dept, Melbourne University, March, 1959.
11 Jenssen, Ditmar (1963), Application of Digital Computers to Weather Analysis and Forecasting and to Problems of the Antarctic Water Budget Conduction in Moving Ice Sheets. PhD thesis: Meteorology Dept, Melbourne University, October, 1963.
12 Jenssen, Ditmar, conversation with the author at Carnegie, Vic., 22 October, 2001.
13 One of CSIRAC’s data registers (note: a register is effectively one location of memory but usually set up independently of the main machine memory).
14 Conversation with Jenssen at Carnegie, Vic., 18 January 2002.
16 ibid. In this conversation Jenssen also mentioned other music from scientific data, including Charles Dodge’s, The Earth’s Magnetic Field [Nonesuch, 1970], made from the data provided by Bartel’s diagrams. The diagrams produce a kind of histogram and Dodge used details of the heights of each column to set the tones for the sounds.
17 It was decommissioned on 24 Nov 1964, and donated to the Museum of Victoria at Spotswood [Bennett, Broomham, Murton, Pearcey and Rutledge, 1994, op cit, p.34]. It remains the only intact computer of its generation in the world and has recently been on display at the Museum of Melbourne.
18 Which was the descendant of Turing’s NPL PilotACE [Carpenter and Doran, 1986, op cit, p.16].
19 See instead: Deane, John (2006b) UTECOM: A Turing Engine for the University of NSW. Killara, NSW: Australian Computer Museum Society.
20 The detail on SILLIAC’s development and history while glossed above (section 3) can be further explored in [McCaughan, 1987, op cit; Deane, 2003b, op cit, and Deane, John (2006a) SILLIAC: Vacuum Tube Supercomputer, Sydney, NSW.: Science Foundation for Physics, School of Physics, University of Sydney, in association with the Australian Computer Museum Society. [2nd edition, for the SILLIAC 50th Anniversary celebrations]].
21 Deane, 2003b, op cit, p.97.
22 McCaughan, 1987, op cit, pp.30-1.
23 ibid, p.31.
24 ibid, p.59.
25 Poole, P.C. (1963) A Study of Variations in the Arrival Rates of Extensive Air Showers, Ph.D thesis in the School of Physics, University of Sydney.
26 According to McCaughan, who, in an email to the author (27 March 2002), remembers that he worked with them himself in 1960. “I have been reflecting on the fact that my 4th year project on Silliac would have had to include those maps that you found in Peter Poole’s thesis. I would not have originated that idea which implies that it came from Crawford and/or Poole, and that it started in the late fifties.”
27 Freeman, Hans C. (1957a) “The crystal Structure of biuret hydrate and X-ray crystal structure calculations on the ‘Silliac’ high-speed electronic digital computer” PhD thesis, School of Chemistry, University of Sydney, 1957.
Freeman, Hans C. (1957b) “Crystallographic Calculations on the SILLIAC Electronic Digital Computer” Australian Journal of Chemistry, vol.10, no.2, p.95.
Freeman, Hans C. (1957c) “SILLIAC Computer Programs for X-Ray Crystal Structure Analysis.” Proc. Conf. on Data Processing and Automatic Computing Machines. Australian Defence Scientific Service, Department of Supply, p.120-1.
28 Bennett has said [Bennett, J.M. (1971) “Computers and the Visual Arts” Aust. Computer Jnl, vol.3, no.4. (Nov. 1971) pp.171-177, p.172] that the use of printers for graphical output by judicious placement of characters on the page goes back to work by x-ray crystallographers at Cambridge University in 1950.
29 From the notes to the Program V26 in the possession of Hans Freeman. The program was V26 in the SILLIAC library, and the source of the numbers was program V7 (or V17) [SILLIAC Fourier summation programs]
30 SILLIAC Program Q5. I haven’t been able to discover when it was written except that it was sometime after the first of the four magnetic-tape stores became available around mid-1960, the remaining three becoming available after March, 1962. See Deane, 2003b, op cit, pp.70, 75 & 78.
31 The picture is produced by dividing the value of the number, z, in each location (x,y) by some number, Δz, that represents the spread of values the user might wish to see between contours. Obviously this depends on the overall range of z in all (x,y). The value of z at each (x,y) is divided by Δz and where the integer part of the quotient is even it places a dot at that (x,y) location on the 32 x 32 grid. Where the integer part of the quotient is odd it leaves a space. Thus, the image appears as alternating bands or surfaces of filled and empty regions (not unlike Ditmar Jenssen’s weather forecast image Fig.14). See the program description for further details: SILLIAC Code Q5 – Basser Computing Department. (This may be difficult to do. The author [SJ] has a photocopy of it in his archive.)
32 SILLIAC Code Q5, Basser Computing Department, p.11.
33 A slight variation on the Hexadecimal or base 16 numbers that program assembler codes use these days.
34 It is possible that this is the program that David Crawford converted into his animation routine.
35 Deane, 2003b, op cit, pp.82-3.
36 The 7040 came from Lucas Heights after they upgraded their capabilities. Since IBM never actually sold machines, you could only rent them, they now had the Lucas Heights machine to dispose of, so they refurbished it and handed it over.
37 A Control Data Corporation machine that effectively became a hard disk and remote console controller for the system.
38 A Digital Electronics Corporation machine that was the first commercially successful small computer for direct use in the experimental laboratory. They became ubiquitous in many university departments over the next decade. They were cheap enough to be dedicated to one process, eg, the control of the X-Ray diffractometer and its goniometer in the crystallography work of the Chemistry Department.
39 Bennett, J.M., Wallace, C.S. and Winings, J.W. (1968) “A grafted multi-access network” Information Processing 68,Proceedings of IFIP Congress 1968, pp.917-922. Edinburgh, 5-10 August 1968.
40 Jenny Edwards, email to Stephen Jones, 26 February 2002.
41 Jacques, conversation with Jones at Frenches Forest, 27 March 2002.
42 June Crawford, email to Jones, 16 March 2002.
43 Bob Donnelly, conversation with the author at Surry Hills, 23 September 2002.
44 While the CRT was selected to bit 1, says Jacques, but Deane comments that it was more likely the empty bits 10 or 11 of the memory because instructions occupied bits 1-8 of the memory. 45 Jacques, conversation with Jones at Frenches Forest, 27 March 2002 – SJ paraphrase. 46 Crawford, email to Jones, 10 April 2002.
44 While the CRT was selected to bit 1, says Jacques, but Deane comments that it was more likely the empty bits 10 or 11 of the memory because instructions occupied bits 1-8 of the memory.
45 Jacques, conversation with Jones at Frenches Forest, 27 March 2002 – SJ paraphrase.
46 Crawford, email to Jones, 10 April 2002.
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