One of the CDC 7600 mainframe computers at the Lawrence Livermore National Laboratory (LLNL). The glass-fronted cabinets in the foreground hold the processors of the computer. The cabinets in the background are the data tape streamers used to record or retrieve information and to load or save programs. LLNL has three of these computers, but the codes on them are gradually being transferred to more powerful Cray-1 supercomputers. The CDC and Cray computers at LLNL form the heart of one of the largest research computer centres in the world.