Early computing using a single university computer such as the one McKenzie learnt on at ScrippsScripps Institution of Oceanography, San Diego, California was established to support marine biological research, but from 1908 onwards pioneered geophysical research in the oceans. Teddy Bullard was a frequent visitor and undertook early ocean floor heat flow measurements with Roger Revelle. In 1962 the University of California established the new Institute of Geophysics and Planetary Physics alongside Scripps in La Jolla. involved writing programmes on punched cards, which were collected once a day; your output came back the next day. “If you imagine trying to learn to programme when you only get one turnaround a day. It was very frustrating, but there was nothing else, so we weren’t aware of quite how wretched it was.” Nonetheless, it was at Scripps that Parker developed his mapping programme, SUPERMAP, which proved easy to modify and update. This went on to become HYPERMAP, one of the more widely-used programmes for plate tectonic reconstructions. Both McKenzie and ParkerBob Parker (1942-present) joined Madingley Rise as a PhD student in 1963, alongside McKenzie; they shared an office and had the same supervisor, Teddy Bullard. Parker was working on the propagation of the electromagnetic field from the ionosphere into the Earth, which demanded an understanding of the oceans. Parker went to IGPP Scripps for post-doctoral research and there he and McKenzie worked out the paving stone model of rigid plates rotating on a sphere about axes. Parker had produced a flexible computer programme to draw maps and he helped McKenzie incorporate earthquake first motions around the edges of the plates as instantaneous velocity vectors, a crucial step in the arguments of McKenzie and Parker 1967. wrote in Fortran, the dominant programming language at the time.