There was also something with file permissions, which were organized as number intervals on the real line. In this way, groups of users could be given permission to access certain files. My old geo-hacker friend was a driving force behind this effort. You youngsters may find it perhaps hard to imagine that there was a time when computers came without a numeric co-processor, or even one on a separate chip. The geodetic co-processor was designed in close cooperation between the Danish Geodetic Institute and Regnecentralen .
Productivity is what counts now.
The golden age is over. Last May, the last of the RC4000 was given a decent burial. Currently such expansions are available up to degree 360, containing no less than 130,000 coefficients and mapping the gravity field world-wide with a resolution of 55 km. He confided that he had acquired a small notebook computer, and was playing around with it. I responded that, also for me, no more Windows.