COMPUTING IN CRYSTALLOGRAPHY: THE EARLY DAYS. Robert Langridge, Computer Graphics Laboratory, University of California, San Francisco, CA 94143, and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA. Jenny P. Glusker, Institute for Cancer Research, Fox Chase Cancer Center, 7701 Burholme Avenue, Philadelphia, PA 19111, USA.

"It is unworthy of excellent men to lose hours like slaves in the labor of calculation which could safely be relegated to anyone else if machines were used" Leibniz (1671)

"As soon as an Analytical Engine exists, it will necessarily guide the future course of science" Babbage (1864)

"The purpose of computing is insight, not numbers" Hamming (1962)

Detailed numerical calculations have been the life blood of our field since it began, and computations for X-ray crystallography rank among the pioneering applications of stored program digital computers, revolutionizing our work and making possible the application of large-scale direct methods to smaller molecules and the determination of the complex architectures of structures of the magnitude of viruses. Furthermore, the numbers generated by these calculations, particularly for large biological molecules, are almost incomprehensible without the now routine use of interactive three dimensional computer graphics to visualize the results and to help generate the insight which the numbers alone cannot provide.

Although the date of origin of the modern computer cannot be fixed as precisely as that of the discovery of X-rays, the celebration of the 50th anniversary of the introduction of ENIAC now being held in Philadelphia illustrates how short is the history of computers. After a brief summary of pre-ENIAC computing, we recall the first use of EDSAC at Cambridge in 1951 by Bennett and Kendrew for protein crystallography, and select some highlights of the early days of the exciting and productive association between computers and crystallographers.