Commemorating 150 years since the death of British scientist Charles Babbage, inventor of the 'Difference Engine' which was the first mechanical calculator and also the 'Analytical Engine' which was the forernner of the modern computer. This coin is the fourth 50p coinin the Royal Mint's Innovation of Science series.
 
*This coin has not been released into general circulation*
 
Obverse: Jody Clark Portrait
Reverse: depicting the workings of Babbage's 'Difference machine, using letters and corresponding numbers from his name (designed by Nigel Tudman and Jas Bhamra).