In 1951, he developed the concept of microprogramming from the realisation that the central processing unit of a computer could be controlled by a miniature, highly specialised computer program in high-speed ROM. This concept greatly simplified CPU development. Microprogramming was first described at the University of Manchester Computer Inaugural Conference in 1951, then expanded and published in IEEE Spectrum in 1955. This concept was implemented for the first time in EDSAC 2, which also used multiple identical "bit slices" to simplify design. Interchangeable, replaceable tube assemblies were used for each bit of the processor. The next computer for his laboratory was the Titan, a joint venture with Ferranti Ltd begun in 1963. It eventually supported the UK's first time-sharing system and provided wider access to computing resources in the university, including time-shared graphics systems for mechanical CAD.