Gavin worked for DEC as a Field Engineer, but his IT career started working for the National Physical Laboratory in Teddington as an Assistant Scientific Officer, calibrating viscometers. He later relocated to the Road Research Laboratory working on computer models simulating car behaviour and road congestion, and assisted the developers of the software.
Gavin grew frustrated with his prospects for career development, and came across DEC in a job advert in the newspaper, who were looking for Field Engineers, responsible for fixing computers. He had some electrical knowledge and had maintained a PDP mini computer in his previous job, so he decided to apply.
The work involved repairing computers in scientific institutions that could not afford large mainframe computers, but needed smaller computers for processing experimental results quickly. In his career with DEC Gavin specialised in hardware, working on prestigious projects including with client British Gas providing software and hardware to digitise large paper maps of gas pipelines across the UK.