The distinctive appearance of the processor of a Cray 1 supercomputer installed at Lawrence Livermore National Laboratory (LLNL), California, USA. Supercomputers are large main frame machines that are able to perform a large number of often highly complex mathematical operations at high speed. They are used in mathematical modelling and simulations, weather forecasting and image processing. At LLNL, the Cray is linked to other large computers (other Cray machines and older Control Data 7600's) via the Octopus network and is used for design calculations in nuclear engineering.