Under this award, Princeton University will purchase CONVEX mini- supercomputer facilities for theoretical and observational investigations. Primary use will be for large scale simulations in cosmology to test the currently considered theoretical models against the increasingly detailed observations of large scale structure and the background radiation fields. The local facilities will be used both for preliminary modelling and for manipulation and display of the results obtained from NSF supported supercomputer facilities. Also significant will be use for processing of both optical and radio images. For both applications, the C-220 with its speed, large memory (512 Mb), and efficient FFT routines is ideal. Princeton University is providing 50% of the purchase price in a cost-sharing arrangement.