Although it made some unique contributions Marconi was not a leading player in the computer industry but there were other UK companies who were, some in particular with whom Marconi got to work closely, so it is useful to reference sources of information on this aspect.
MOSI - Museum of Science and Industry, Manchester
The National Museum of Computing
The Jim Austin Computer Collection - his comprehensive list
Turing Archive for the History of Computing
Early British Computers - this is referenced in our page and is said to be being updated so we should get into it
UK National Archive for the History of Computing