SILLIAC
Encyclopedia
The SILLIAC an early computer
built by the University of Sydney
, Australia
, was based on the ILLIAC and ORDVAC
computers developed at the University of Illinois
, which in turn were based on the IAS
architecture developed by John von Neumann
.
SILLIAC had its genesis in late 1953 when Harry Messel
, the dynamic new head of the School of Physics, and John Blatt, newly arrived researcher, both independently realised that the School needed an electronic computer as a tool for theoretical physics
. Whilst the first computer in the southern hemisphere, the CSIR Mk 1, was already running elsewhere on the University of Sydney grounds, there were several serious impediments to its use by the School of Physics: The CSIR Mk 1 was fully occupied with CSIR
research and John Blatt found its staff very unhelpful; and, as a serial architecture computer, it was far too slow for the sort of problems that Blatt and Messel envisaged. The solution was for the School to build its own computer.
A suitable computer (ILLIAC) already existed at the University of Illinois and Blatt and Messel chose to copy it, rather than design a computer from scratch. The University of Illinois were happy to provide plans and assistance and estimated the cost of building a copy at US$110,000. John Algie, then maintenance engineer for CSIRAC
, reviewed the costings and estimated the cost at AU£
35,200 (roughly A$
2,000,000 in 2006 dollars). Based on this, a decision to proceed was made at the end of 1953. A mutual friend introduced Messel to Adolph Basser, who donated AU£50,000 towards the computer.
Like most of the IAS family, SILLIAC was not an exact copy of ILLIAC. One important change was the use of 2C51 valves
in place of the more common 6J6. The 2C51 had been developed by Bell Labs
for use in undersea telephone repeaters and had about 5 times the life (for 6 times the cost). This decision significantly improved the reliability
of SILLIAC compared to its contemporaries.
Like other early computers, SILLIAC was physically large. The computer itself was a single large cabinet 2.5m high, 3m wide and 0.6m deep in one room. Its power supply occupied a second room and air conditioning
required an additional room in the basement.
In July 1954, Standard Telephones and Cables (STC) was contracted to build the computer, with testing and installation performed by technicians within the School of Physics.
On July 4, 1956, SILLIAC successfully passed its self test and a test run of a scientific program. On the following day, it ran its first "production" program and users were provided with regular access from July 9. The official opening was on September 12.
Barry de Ferranti, a pioneer involved in the construction of SILLIAC described the main cabinet of the computer as about 2 metres high, 1 metre deep and 5 metres long with glass panels at the front and light switches that indicated what was going on inside. It ran until May 17, 1968 when it was replaced by a faster and bigger machine. SILLIAC has now been broken up into pieces.
and others are displayed at Sydney University.
In March 2008, the Australian Computer Museum Society was seeking alternate storage, or risk its collection including important components of SILLIAC being scrapped.
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
built by the University of Sydney
University of Sydney
The University of Sydney is a public university located in Sydney, New South Wales. The main campus spreads across the suburbs of Camperdown and Darlington on the southwestern outskirts of the Sydney CBD. Founded in 1850, it is the oldest university in Australia and Oceania...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, was based on the ILLIAC and ORDVAC
ORDVAC
The ORDVAC or Ordnance Discrete Variable Automatic Computer, an early computer built by the University of Illinois for the Ballistics Research Laboratory at Aberdeen Proving Ground, was based on the IAS architecture developed by John von Neumann, which came to be known as the von Neumann architecture...
computers developed at the University of Illinois
University of Illinois at Urbana-Champaign
The University of Illinois at Urbana–Champaign is a large public research-intensive university in the state of Illinois, United States. It is the flagship campus of the University of Illinois system...
, which in turn were based on the IAS
IAS machine
The IAS machine was the first electronic computer built by the Institute for Advanced Study , in Princeton, New Jersey, USA. It is sometimes called the von Neuman machine, since the paper describing its design was edited by John von Neumann, a mathematics professor at both Princeton University...
architecture developed by John von Neumann
John von Neumann
John von Neumann was a Hungarian-American mathematician and polymath who made major contributions to a vast number of fields, including set theory, functional analysis, quantum mechanics, ergodic theory, geometry, fluid dynamics, economics and game theory, computer science, numerical analysis,...
.
SILLIAC had its genesis in late 1953 when Harry Messel
Harry Messel
Harry Messel is a retired Australian physicist and educator.Messel was born in Canada of Ukrainian parents. He was brought up in Levine Siding in Manitoba and attended Queen's University, Kingston, Ontario. During the Second World War he served as a paratrooper with the Canadian Forces.Messel...
, the dynamic new head of the School of Physics, and John Blatt, newly arrived researcher, both independently realised that the School needed an electronic computer as a tool for theoretical physics
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
. Whilst the first computer in the southern hemisphere, the CSIR Mk 1, was already running elsewhere on the University of Sydney grounds, there were several serious impediments to its use by the School of Physics: The CSIR Mk 1 was fully occupied with CSIR
Commonwealth Scientific and Industrial Research Organisation
The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...
research and John Blatt found its staff very unhelpful; and, as a serial architecture computer, it was far too slow for the sort of problems that Blatt and Messel envisaged. The solution was for the School to build its own computer.
A suitable computer (ILLIAC) already existed at the University of Illinois and Blatt and Messel chose to copy it, rather than design a computer from scratch. The University of Illinois were happy to provide plans and assistance and estimated the cost of building a copy at US$110,000. John Algie, then maintenance engineer for CSIRAC
CSIRAC
CSIRAC , originally known as CSIR Mk 1, was Australia's first digital computer, and the fourth stored program computer in the world. It was first to play digital music and is one of only a few surviving first-generation computers .The CSIRAC was constructed by a team led by Trevor Pearcey and...
, reviewed the costings and estimated the cost at AU£
Australian pound
The pound was the currency of Australia from 1910 until 13 February 1966, when it was replaced by the Australian dollar. It was subdivided into 20 shillings, each of 12 pence.- Earlier Australian currencies :...
35,200 (roughly A$
Australian dollar
The Australian dollar is the currency of the Commonwealth of Australia, including Christmas Island, Cocos Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru and Tuvalu...
2,000,000 in 2006 dollars). Based on this, a decision to proceed was made at the end of 1953. A mutual friend introduced Messel to Adolph Basser, who donated AU£50,000 towards the computer.
Like most of the IAS family, SILLIAC was not an exact copy of ILLIAC. One important change was the use of 2C51 valves
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
in place of the more common 6J6. The 2C51 had been developed by Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
for use in undersea telephone repeaters and had about 5 times the life (for 6 times the cost). This decision significantly improved the reliability
Reliability engineering
Reliability engineering is an engineering field, that deals with the study, evaluation, and life-cycle management of reliability: the ability of a system or component to perform its required functions under stated conditions for a specified period of time. It is often measured as a probability of...
of SILLIAC compared to its contemporaries.
Like other early computers, SILLIAC was physically large. The computer itself was a single large cabinet 2.5m high, 3m wide and 0.6m deep in one room. Its power supply occupied a second room and air conditioning
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...
required an additional room in the basement.
In July 1954, Standard Telephones and Cables (STC) was contracted to build the computer, with testing and installation performed by technicians within the School of Physics.
On July 4, 1956, SILLIAC successfully passed its self test and a test run of a scientific program. On the following day, it ran its first "production" program and users were provided with regular access from July 9. The official opening was on September 12.
Barry de Ferranti, a pioneer involved in the construction of SILLIAC described the main cabinet of the computer as about 2 metres high, 1 metre deep and 5 metres long with glass panels at the front and light switches that indicated what was going on inside. It ran until May 17, 1968 when it was replaced by a faster and bigger machine. SILLIAC has now been broken up into pieces.
Conservation
Some pieces of SILLIAC are at the Powerhouse MuseumPowerhouse Museum
The Powerhouse Museum is the major branch of the Museum of Applied Arts and Sciences in Sydney, the other being the historic Sydney Observatory...
and others are displayed at Sydney University.
In March 2008, the Australian Computer Museum Society was seeking alternate storage, or risk its collection including important components of SILLIAC being scrapped.
Hardware Specifications
- Parallel, asynchronous operation. Approximately 13,000 adds, 1400 multiplies or 1200 divides per second
- MemoryComputer memoryIn computing, memory refers to the physical devices used to store programs or data on a temporary or permanent basis for use in a computer or other digital electronic device. The term primary memory is used for the information in physical systems which are fast In computing, memory refers to the...
: 1024 words of 40 bitBitA bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
s using 40 Williams tubes - Two 20-bit instructions per word.
- Approximately 150 operations on 2 registerProcessor registerIn computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
s - Paper tapePunched tapePunched tape or paper tape is an obsolete form of data storage, consisting of a long strip of paper in which holes are punched to store data...
input, paper tape or printer output. Four magnetic tapeMagnetic tape data storageMagnetic tape data storage uses digital recording on to magnetic tape to store digital information. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs actual writing or reading of data is a tape drive...
units added in 1958 - Initially 2768 valves. Increased to 2911 during 1958 upgrade
- Power consumption: 35kWWattThe watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
- Average of 11 hours between failures
External links
- The Science Show about SILLIAC
- David Green's SILLIAC page - Programming Manuals and an emulator
- Description and Image of a Component in the collection of the Powerhouse MuseumPowerhouse MuseumThe Powerhouse Museum is the major branch of the Museum of Applied Arts and Sciences in Sydney, the other being the historic Sydney Observatory...