Electronic computer and related papers, KUKAC 1, metal / plastic / paper / Bakelite, designed and made by Allan Bromley, Australia, c. 1970
At the time, the design of the KUKAC computer was a break-through for a very economical computer suited for use in high schools and similar institutions. From a design point of view, a number of economic measures were taken, in spite of which a high level of performance has been achieved.
This object is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.
Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Antikythera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.
The KUKAC 1 computer is Professor Bromley's homemade computer. In the early 1970s Professor Bromley stated that there was a need for an economical computer for teaching purposes, particularly for high school and university students. The cost at the time of $5,000 to $10,000 for a suitable computer was prohibitive. Professor Bromley set about building a computer sufficient to support a simple higher level language, such as BASIC or a subset of APL, and an assembler and simulator for a simple mini computer. The cost of parts should not exceed $500, and he thought that most schools could find on their staff or in the local community someone prepared to assemble the computer for little or no charge. If labour and other indirect costs were included, the price would be raised to $1,000.
This is a digital computer, using a 16-bit word size. This size was adopted, because it was simple and economic and well supported by current MSI components. The computer has three functional components: a scratch pad, an arithmetic logic unit, and an input-output bus and memory.
The scratch pad consists of twelve general-purpose and four special-purpose shift registers. The logic unit performs operations on the contents of selected scratch pad registers. All arithmetic is performed using standard 2-complement logic, bit-serial techniques. The main memory is 512 words, which may be expanded in increments of 256 words. It is assembled from MOS LSI shift registers, giving an effective memory cost of around 1 cent per bit.
Standard modules are used, and wiring is point-to-point. A number of integrated circuits (ICs) were installed on homemade circuit boards. A cassette recorder is used for storage back-up. The equipment included a digital to analogue converter to drive the display. Paper tape reader and punch were also required, as a number of instructions were stored on punch cards. Professor Bromley suggested that a modified television set could be used as a simple output device and to display the operation of the computer. He suggested that a cassette recorder could be used to back-up the store, a cheap electric typewriter could provide hard copy output, and a calculator for keyboard and display.
It is understood that the design was completed about 1970. While a prototype was used for training in the Basser Department, it never had a wide influence in schools, because the computer market in the early 1970s opened up quite suddenly, and prices came down rapidly. Professor Bromley designed an improved version, KUKAC-2, which was launched, using logic and chips designed in the Department.
See: Allan G. Bromley, "A Design for an Economical Serial Micro-Computer", Technical Report No. 756, Basser Department of Computer Science, School of Physics, The University of Sydney, October, 1972.