In 1953, whilst still a post-graduate research student at Manchester University, Grimsdale achieved one of the first major landmarks in his career with his design and development work on the Metrovick 950, the world's first computer made from transistors rather than valves or electromechanical devices. The computer used early point-contact transistors which were the first generation of transistors, however later developments of the machine used more advanced junction transistors which offered better performance.