Current searches for ‘TIFR’ on Google news yield stories about the participation of the Tata Institute of Fundamental Research in the Big Bang experiment. But, even as scientists are in search of the ‘god particle,’ my conversation with Prof Sugata Sanyal of the Institute’s School of Technology and Computer Science travels back in time… To an era when TIFR built computers despite challenges.
“What is so different about research in computer science, from the work in other disciplines?” I nudge Sugata, during the course of a recent email exchange. Computer science is a separate discipline, but is never disjoint from other disciplines, he clarifies.
In good old days when the power of computers was limited, it was more of hardware efforts, based on (mainly digital) electronics and engineering, explains Sugata. “Subsequently, when the power of computers increased by leaps and bounds, and system software opened many vistas of opportunities to the users, computer science became much more theoretical and had much overlap with various branches of mathematics.”
Excerpts from the interview.
Can you tell us about the computers built in India, by TIFR?
The Tata Institute of Fundamental Research was founded by Dr Homi J. Bhabha in 1945. He had the foresight of taking this institute to a height where it will be the leading research centre in India and will be at par with other similar research organisations in the world. And Bhabha developed TIFR into a multi-disciplinary research institute.
Research in computer science and electronic instrumentation got started in the early 50s at TIFR. India started taking her first steps towards the digital computer era, and TIFR, in the next three decades (the 50s, 60s and 70s) developed three indigenous computers.
From 1954 to 1977, TIFR developed ‘TIFR Automatic Calculator’ or TIFRAC, the Online Data Processor (OLDAP), and a third, a highly reliable ruggedised computer using bit-slice microprocessors.
A first-generation mainframe computer developed for scientific computations, the TIFRAC made India the first country in Asia to have built such a machine when it was commissioned on February 22, 1960. The then Prime Minister Jawaharlal Nehru gave TIFRAC its name when he visited TIFR on January 15, 1962.
Developed in 1967, the second computer OLDAP was primarily intended for highlighting the utility of computers in real-time situations in general and for real-time control applications in the field of nuclear physics experimentations in particular.
The third one, a 16-bit highly reliable computer system was designed, developed and tested completely with peripheral devices in 1977. The processor acted as the central controlling element for a rugged mobile exchange of the high availability computer system class.
What were the challenges that had to be overcome when building these computers?
The main assembly of TIFRAC, which was based on vacuum tubes, was housed in a massive steel rack measuring 18 ft X 2.5 ft X 8 ft. It was fabricated from modules of 4 ft X 2.5 ft X 8 ft. It was about 30 ft long but had a memory of just one kilobyte.
A manual console served as the input/output control unit of the computer that had a ferrite core memory of just 1024 words. This amounted to one KB of RAM of a computer word of 40-bit width. Input to the TIFRAC was by means of a punched paper tape and the output was either printed out directly or punched on paper tape.
A cathode ray tube display system was developed to serve as an auxiliary output to the computer for analogue and digital display of both graphs and alpha-numeric symbols.
The scientists first built a workable pilot model by September 1956, and after it was kept operational for about a year, work for the main machine began; and the full-scale machine was finished in February 1959.
It was the infancy of computer science in the country, and it was a challenge to put together tens of thousands of individual components – resistors, capacitors, wires and vacuum tubes. Besides, the power requirement, 20 KW, posed some severe problems normally not encountered in conventional electronic systems.
In less than five decades the computing world has metamorphosed itself to mind boggling levels. In comparison, TIFRAC era appears like the Stone Age computing. However, it was a necessary starting point to use computers for academic purpose.
TIFR ran special computer programming courses all over India for a variety of user groups: the Government, universities and R&D organisations; all of them used TIFRAC for a wide variety of applications. Well over fifty organisations were using TIFRAC computational facility. TIFRAC was the single factor that introduced the culture of using computers for scientific research as well as governance.
The digital computer scene in India changed a lot between 1954 (initiating TIFRAC project) and 1964 (termination of TIFRAC project). IBM computers had captured the commercial user market. The TIFRAC experience demonstrated that manufacturing general-purpose mainframe machines would not be cost-effective at that point. PDP mini-computers had already appeared in the international market.
But there definitely was a requirement for special-purpose digital computers in, say, scientific, industrial, and defence applications. In these fields, there were requirements for on-line/real-time data collection, data processing, and process control applications. Mainframe machines with their demand on space, power and finance were out of reach for these users. It was worth experimenting with the development of a mini-computer with on-line/real-time input/output facilities. While computers were being used in various offline applications, there was virtually no progress in online programs. OLDAP came into being to bridge this gap.
It used the second generation technology, i.e. transistors, diodes, and printed circuits. It was still discrete component-based and used electrical wires for intra-panel and inter-panel connections. It measured (l) 10 ft X (h) 6 ft X (d) 2 ft including the power supply. Normal air-conditioning and cooling fans mounted in racks were sufficient to control working temperature.
OLDAP had random access magnetic core memory as primary memory (12 bit, 8K words) and magnetic drum as secondary memory (64K words). Peripheral I/O units included console typewriter, paper tape reader and punch as conventional I/O devices and analogue to digital converter, with 8-channel multiplexer as real-time input device for simultaneously accepting up to eight real-time inputs.
OLDAP had some features, which when judiciously used, would reduce the frequency of accessing memory, speeding up the program execution – significant for on-line and real-time applications.
Now the hardware challenges. During TIFRAC fabrication, creativity played a major part. Individual circuit card design, back panel design, rack design for housing all the circuitry, laying of interconnecting cables, air flow control for cooling, and design of the console were some of the tasks which routinely fell in this category.
In the case of OLDAP, apart from card, back panel and rack designs, there were tasks which need special mention, viz. dynamic aligning and coating of the magnetic drum, creation of printed circuit photographic masks (templates) and setting up printed circuit fabrication mechanism. Printed circuit technology was used for all card modules of OLDAP.
Later, a need arose for the development of a rugged digital computer to form the nucleus of complex online systems required for two major applications – a general purpose medium-size digital switching system and a data acquisition, and processing system for weather radar.
These applications called for high computational speed, reliability, ruggedness, ease of maintenance and easy transportability. The machine which was developed to meet these requirements provided a stimulating challenge and ample scope for design innovation.
The basic development of this micro-programmed computer around bit-slice microprocessors was completed in a relatively short time, between September 1, 1977 and December 27, 1977.
The basic objective of developing a highly reliable computer was achieved, not through the usage of highly reliable components alone, but through a novel and innovative micro-programmed scheme. In developing the computer, hundreds of medium and small scale integrated (MSI and SSI) chips were replaced by a few bipolar bit slice microprocessor chips and appropriate support chips.
The field endurance test of the mobile electronic telephone switching system amply proved the suitability of this design approach for numerous applications in developing countries which require ruggedised processors.
Tests carried out at the Cyclone Warning Radar Stations in Madras (now Chennai), India proved the adequacy of the design for non-mobile data processing type of activity. The success of the processor for the digital switching application proved its reliability in the mobile role, thus establishing the versatility of the design.
Starting from these steps, we have moved to the present time when the country can boast of 15 supercomputers and a battery of software personnel who have proved their mettle all over the world.
What are the lessons from these projects?
TIFRAC and OLDAP had multifaceted fallouts. Firstly, these machines proved that it was possible to indigenously develop computers in India and that we were not far behind the developed countries in terms of knowledge of engineering and computer science. These machines provided the scientists from various fields with the much-needed support of ample calculation power. Apart from fulfilling these fundamental needs, these machines and the culture initiated at TIFR formed the basis of a series of computer science and engineering organisations that had subsequently come up in India.
With the computers in regular use, India was able to launch its own in-house maintenance farms, replacing international big names in the industry like IBM. It not only resulted in monetary savings but also created a pool of computer technology trained personnel who later formed organisations such as Computer Maintenance Corporation Ltd (CMC) and Electronic Corporation of India Ltd (ECIL).
The increasing use of computers gave birth to many organisations where computer science and engineering started developing. For example, Tata Consultancy Services (TCS) was founded in 1968.
In a manner of speaking, today’s IT industry of India, with its far-flung reach to every part of the world, had its seed germinated in the laboratories of TIFR.
The Rugged Microprogrammed Computer, developed in the 70s, helped in the area of developing self-reliance in designing highly sophisticated high-availability computers and similar systems. It also helped in spawning this culture to various industries, and it finally gave birth to design and innovation of research and development in the area of security.
Would you like to talk about the benefits of computer projects that spilled into other domains of the Institute’s research?
These design and development efforts at TIFR were definitely started by the then computer group. The initial aim of TIFRAC was to help various groups (say, the astrophysicists) with their huge computational needs. Apart from that, the research helped in building an electronic R&D culture that benefited many other research domains.
For instance, a very senior scientist developing sophisticated instruments for chemical or physics experiments never hesitated in coming straight to the computer group for discussing his problems and in borrowing sophisticated electronic components. Microwave group of TIFR was highly connected with the computer group in its developmental efforts and also in its manpower development. Similar connectivity was there with the other groups of TIFR as well.
A PhD from Mumbai University, MTech from IIT, Kharagpur, and BE from Jadavpur University, Sugata Sanyal (www.tifr.res.in/~sanyal) is on the editorial board of six international journals. He is co-recipient of VASVIK award for Electrical and Electronics Science and Technologies (combined) for the year 1985. Sanyal was a Visiting Professor in the Department of Electrical and Computer Engineering and Computer Science in the University of Cincinnati, Ohio, US in 2003. He has been an Honorary Member of Technical Board in UTI (Unit Trust of India), SIDBI (Small Industries Development Bank of India), Coal Mines Provident Funds Organisation (CMPFO), MAHAGENCO and other organisations. He was an active member of the team which developed the Rugged Microprogrammed Computer, based on bit-slice microprocessors.