1900 Series History
Around 1963 Ferranti were looking for a system below the speed of
Orion and Atlas to replace Pegasus, Mercury and Sirius.
Their Canadian subsidiary, Ferranti Packard had recently visited the UK, and based on their knowledge
of the Ferranti they designed the FP6000.
The first FP6000 was installed and running at the US Federal Reserve Bank in
New York in March 1963.
A joint ICT/Ferranti team visited Toronto in
March 1963. The interest was in both the machine architecture and how they had produced it in such a
short timescale. The party reported back that it would be quicker to build
the FP6000 than design an alternative.
A later visit by Arthur Humphreys of ICT and colleagues were equally impressed and saw it as a
definite competitor to the
RCS systems (an IBM copy) that was being looked at by ICT.
An ICT Computer Range
About this time, it was beginning to be realised that producing a range of incompatible systems
was both labour intensive and expensive. Having a system that could cover a range of different sizes and speeds
would have distinct advantages. IBM announced the System/360 series and others need to compete.
The only way to do that in the short term was to base a series on hardware that was already
in production. ICT selected the FP6000 as the basis of their range
and this speeded up the ICT/Ferranti merger.
The 1900 Series was announced in September 1964, only six months after IBM launched System/360
and some 1900 models were delivered earlier than their IBM equivalents.
The FP6000 was based on logic cards developed in Ferranti Wythenshawe for Orion 2.
Some major changes had to be made to the architecture to turn it into a range. The order code had to be altered to allow
the memory size to be greater than 128K 6-bit characters.
Atlas was demonstrating the advantages of a rich operating system
and this resulted in the development of GEORGE III.
The FP6000 became the ICT 1904 and with floating point as the 1905.
More powerful machines - the 1906/1907 - were planned and included in the initial announcement.
Faster machines pushed the technology and the architecture.
Smaller machines needed to be made cheaper. Charlie Portman of ICT was instrumental
in showing that cost effective smaller systems could be built and
eventually it was possible to go down to the 1901.
Long timescales in IBM's delivery of System/360 and the cheaper cost of ICT's 6-bit systems
gave ICT a price advantage that allowed them to sell well in Europe and outside the USA.
Long-term, 6-bit charcters and 48-bit words became a distinct disadvantage and there was always going to be
a need to introduce a new range in the not too distant future.
The 2900 series was finally launched in 1974.
For information on the ICL 1900 Series see http://www.fcs.eu.com/icl1900/index.html.
Also see David Barron's Fragments of an old testament, Computer Bulletin - Sept 1976.
In the beginning was the FP6000
which was made by Ferranti-Packard in a distant land
And there were in another country at that time
divers International Computers and Tabulators
and though they did tabulate
as their fathers before them
yet they could not compute
And they said unto one another
let us go even unto West Gorton
to see this marvel
that has come to pass
and they beheld the FP6000
and saw that it was good
And they said
let us offer many shekels
that the FP6000 may be ours
and Ferranti did say
lo here are men who will pay
for what loseth us much money
Then the International Computers and Tabulators
did take the FP6000
clothed it in panels of blue
and did call it the 1905
thus was accomplished the birth
of the 1900 series
And on the next day
they created the 1904
which was the image of the 1905
but lacked a floating point unit
next did they fashion the 1902 which was slower
and the 1903 which was the same
but with a floating point unit
Finally they did fashion the 1907
a mighty engine for the crunching of numbers
and the 1906 that lacked a floating point unit
and the unbelievers asked
who shall purchase a scientific computer
that hath no floating point unit
and none could answer
Yet another time they salesman said
behold the great multitude
that clamour crying out
lo we have mighty programs
yet the 1905 hath not sufficient core to hold them
so there was created the 1905E which much store
and the 1905F that some did buy
believing the F to signify fast
though none did know for a certainty
and they did yoke together two 1905s
like unto a pair of oxen
to make the 1907F
and no man could comprehend the reason therefor
Then the salesman said
verily we have so many machines
that we know not what we sell
neither do the customers know what they buy
and the engineers said
a new technology hath been revealed to us
in platters of many layers
let us make a new series called the a series
and let there be the 1901A 1902A 1903A AND 1904A
and the company saw that it was good
And the devil taketh the company to a high place
and showeth them the IBM 195 and the CDC6600
and they said let us fashion a mighty machine
like unto the walls of jericho
and call it the 1906A
and let there be set up a graven image
called George 3
that the heathen may worship
and it was accomplished
Now the time was come when there should be fulfilled
the prophecy that was written
in that time they shall travail
and bring forth a New Range
And it came to pass
that although the time was long passed
that the new range should be delivered
yet it did not appear
and there was much wailing and gnashing of teeth in the land
And there arose instead a false prophet
who did privily sell semiconductor stores
wherewith were made the 1903s and the 1904s
that the people might forget the new range
in wonder at a store so fast
that the processor could not keep pace with it
And there came forth in succession the 1903T and
and the heathen were confused
knowing not which machine was which
In that season they did call together
a monstrous gathering of the press
and there appeared a spokesman of the company
saying Behold I bring you tidings of great joy
for unto you is available
and if peradventure you are willing to wait
and there is System B
that controlleth both their going out and their coming in
But certain unbelievers gathered together privily
and murmured among themselves saying
truly the mills of System B grind fine
but they grind exceeding slow
And the spokesman replied
O Ye of Little Faith
Is it not written in your contract
that all shall be accomplished
even unto the fourth benchmark
and the unbelievers answered
how can these things be