Exchangeable Discs - late 1960s

An EDS8 8MB disc from the days of the first UEA computer an ICL 1905E. The hand (and presumably the watch) are believed to be those of Alan Coombe. When the 5E was replaced with a 1903T we moved up to EDS60s (60MB) which required two hands to lift ! The disc drives were about washing machine size and the PF56 controllers with dedicated teletype (keyboard & paper output) were of a similar size. A nice feature of visible heads was being able to tune the discs by watching the head movement . It was also possible under GEORGE 3 to place a special residence for filestore directories in the middle cylinders so that head movement to files was then mainly in or out from the centre. The whole of UEA filestore in this period was online to two or three EDS60s i.e. 180MB with GEORGE automatic archiving of files to 9 track tapes. File retrieval from tape was transparent to users with GEORGE requesting an Operator tape load when a users job referenced a currently offline file. This feature was way ahead of its time in 1974 and a tribute to the British designers. The following American VAX/VMS and Unix operating systems did not have anything like this as a built in feature and in late 2008 we are only just piloting a similar service with IBM HSM. Alan Coombe authored a GEORGE to MAXIMOP filestore transfer system based around an exchangeable disc which had to be physically moved between the two systems.