Connections in the History of Australian Computing - History of Computing: Learning from the Past - page 9

and speed, carry out processing quality checks and compare the predicted impact
point to the rocket range boundaries. The final stage could be to instruct an errant
missile to self-destruct, so it was named after the Greek god of death, ATROPOS .
They also wrote a simulator and tested their software on WRE's IBM 7090 . Then
they generated test radar data there too and ATROPOS was placed in operation at the
end of 1963 [54]. In 1964 it was
“one of the few, and certainly the largest real time data processing system operat-
ing in Australia. Yet with the exception of the radars and plotting tables, all the
equipment involved was designed by WRE and built either in the WRE or by local
industry” [55]
The system was successful and reliable, and was operated until 1974 when it was
replaced by a commercial computer [56].
12 ARCTURUS
Following David Wong's completion of SNOCOM he built a large digital trainer,
NIMBUS , and from the early 1960s started thinking about a very economical, general
purpose computer for the Electrical Engineering Department at Sydney Uni. There was
no budget at all but David started small related projects: a printer controller, and a re-
markably fast paper tape reader. He also started salvaging electronic components and
developing the design with SNOCOM style hardware. By mid 1964 he had a complete
design, and a small amount of funding to build a computer for educational use [57].
David bought core memory, a paper tape punch, and the necessary components to
construct his machine in the University. It was completed in 1966 at a cost around
£5,000. There was also a competition to name it, and ARCTURUS 13 won [58].
While there were other computers available ARCTURUS was fast and convenient,
and its hardware could be modified for special projects. For example, when IBM do-
nated a large disc drive (a RAMAC 305 ) in 1971, it was easiest to build an interface
for ARCTURUS (which was done by Kevin Rosolen) [59].
By 1975 small and cheap commercial computers designed for digital control were
available and ARCTURUS was replaced by a Digital Equipment PDP-11/45 [60].
13 Summing Up
History tends to make champions of inventors and early Australian computing has a
notable number of inventions. This brief overview of the obvious early milestones
shows quite a mesh of influences. British radar provided basic electronic techniques,
the critical delay-line memory device and an excellent reason to automate calcula-
tions. UK academic Douglas Hartree knew David Myers, Trevor Pearcey and John
Ovenstone. John von Neumann's two fundamental designs, EDVAC and the IAS
Computer , directly influenced CSIRAC and SILLIAC , and had surprising influences
on WREDAC and CIRRUS via Cambridge's EDSAC . Published US designs were
13 In Greek mythology Zeus created Arcturus to guard the bear.