The case for a new microfilm recorder to replace the SC4020 was made to the Atlas Computer Committee in September 1972. The SC4020 had been an excellent investment for the Laboratory but it was becoming increasingly difficult to maintain the system. The SC4020's addressability (1024 by 1024) with a resolution nearer 400 by 400 was no longer impressive. It was difficult to produce grey scale output and colour output required external film processing with several negatives as input and the likelihood that the positioning of the image had changed between the production of the separations. No upgrading of the SD4020 was available, and the machine itself was constructed of now obsolete hardware.
One attraction of modern microfilm recorders was the incorporation of some intelligence via a dedicated processor thus giving more flexibility. Of the machines surveyed the Information International Inc FR80 stood out as the best device both for performance and quality of output.
The Committee were unconvinced as to the need for a device of that quality, and the Laboratory was asked to present the case for graphical presentation becoming more important to users, particularly those who would make use of the IBM 360/195.
The Committee also asked the Laboratory to establish the cost of refurbishing the SD4020 and to look at the possibility of Ferranti providing the microfilm recorder.
There had been ongoing discussions with Ferranti for several years with regard to microfilm recorders. Ferranti (and also Plessey) had some interest in this market but tended not to be competitive with the US offerings.
A revised case was made to the Committee in March 1973. The needs of a number of large users who were making extensive use of the SC4020 for film generation was given. A factory refurbished SC4020 would cost £20,000 but would have none of the features of the newer recorders. It was made of out-of-date circuitry and would inevitably lead to awkward maintenance problems. The Committee were still unconvinced as to the need for a £200,000 device and asked the Laboratory to prepare a case to go forward to SRC's Science Board in October and, if they were convinced of its merit, the Committee would let it go forward. Approval eventually came in the summer of 1974 and a contract placed with the need for the equipment to be installed and paid for before the end of the financial year (1 April 1975).
