MADBLOC, A Program for Digital Simulation of a Hybrid Computer

means of simulating system dynamics. These programs are equipped with block-oriented &dquo;operators&dquo; such as integrators, adders, limiters, resolvers, etc. In general, however, the early digital simulation programs were not provided with any logical &dquo;equipment&dquo; or capabilities except relays, nor was memory provided. In these respects these programs suffered from the same limitations in logical operations as the analog computers of the same era. The first effort to overcome the deficiencies in these programs paralleled one of the more important basic improvements in analog computer design to appear in many years-the addition of memory through the use of integrator mode-switching.A This improvement was recently added to DYSAC7 by R. L. Schaefer of the Wisconsin group working on digital simulation.