An invitation to the
Atlas Computer Laboratory
of the
Science Research Council
at Chilton, Didcot, Berkshire
for the
CLOSING CEREMONY
of the
FERRANTI - ICL
ATLAS - 1
- the Laboratory's original computer
by
Sir Brian Flowers, FRS
Chairman of the Science Research Council
on
Friday, 30th March 1973
PROGRAMME
11.00 | THE LABORATORY IS OPEN TO GUESTS |
12.00 | THE DIRECTOR - DR J HOWLETT, CBE WILL BE AVAILABLE TO TALK TO THE PRESS REPRESENTATIVES IN THE CONFERENCE ROOM |
13.00 | BUFFET LUNCH |
14.30 |
CLOSING DOWN CEREMONY Mr Basil de Ferranti will speak about the Atlas project Professor David Howarth (who led the team who wrote the Supervisor) will run the last program Sir Brian Flowers will switch off the machine |
15.30 | TEA WILL BE SERVED |
Atlas, designed in the University of Manchester in 1958 to 1961 by the distinguished team led by Dr Tom Kilburn - now Professor Tom Kilburn, FRS - and manufactured initially by Ferranti Limited, whose Computer Department later formed an important part of ICL, was a great and classic machine.
It was remarkably advanced for its day, pioneering many features , which have had a profound effect on computer design and use. Probably the most important were first the paged store, which made possible among other things the concept now called virtual memory; and second the Supervisor, which was the first instance of a comprehensive and largely automatic operating system. The Chilton machine, which was the third of the 6 which were made, has had 8½ years in service and has enabled many research workers, in all the British universities, to tackle projects which otherwise would have been beyond them. Here are some facts about our machine and the work it has done in its busy life.
(the Atlas word is 48 bits, organised in 8 6-bit characters)
NB The paper tape equipment will handle 5, 7 or 8 track tape
JUNE 1964 | Installation and commissioning started |
OCTOBER 1964 | Start of "at risk" service |
MAY 1965 | HANDOVER and acceptance period began |
FEBRUARY 1966 | Full 3-shift operation |
MAY 1966 | FINAL ACCEPTANCE |
FEBRUARY 1968 | DATA PRODUCTS DISC AND SIGMA 2 ADDED TO THE SYSTEM |
MAY 1969 | Multi access system in full operation |
30 MARCH 1973 | End of computer service |
Scheduled hours | 44,500 |
Available hours | 43,000 |
% AVAILABILITY | 97 |
NUMBER OF JOBS HANDLED | 836,000 |
VALUE OF WORK DONE | £10.8M |
NUMBER OF UNIVERSITY PROJECTS SUPPORTED | 2,300 |
Input cards | 300M cards |
Input paper tape | 4000M characters |
Output lineprinter | 800M lines |
Output cards | 17M cards |
Magnetic tape transfers | 500M blocks |
Drum transfers | 300M blocks |
USE OF CPU - Proportion User programs | 0.82 |
USE OF CPU - Proportion Supervisor | 0.12 |
USE OF CPU - Proportion Idling | 0.06 |
Number of University Projects supported | 2,300 |
% of time (1972) to University use | 89% |
% of time (1972) to Government Departments | 2% |
% of time (1972) used by FORTRAN | 71% |
% of time (1972) used by ALGOL | 12% |
% of time used for compilation of programs | 7-10% |
Average job length 1966-1967 | 121 seconds |
Average job length 1968-1970 | 142 seconds |
Average job length 1970-1973 | 198 seconds |