SCADS: A PROGRAMMING SYSTEM FOR THE SIMULATION OF COMBINED ANALOG DIGITAL SYSTEMS.

Numerous attempts to obtain a large scale analog computer at Carnegie Tech have been countered with the argument that the digital computer, if properly programmed, is capable of solving most problems which normally admit to solution by analog computer techniques. The SCADS system has been designed and implemented on the Control Data G-20 computer in order to facilitate the process of properly programming this machine to aid in the solution of analog computer oriented programs. In most instances, only a few hours of individual study prove to be sufficient preparation for the writing of successful SCADS programs. The class of problems which are solvable on an analog computer includes 1 ordinary differential equations with specified initial conditions 2 certain types of integral equations 3 difference equations with specified starting conditions 4 combined systems of integro-differential-difference equations, and 5 the simulation of physical systems which can be characterized by equations of the above types. In addition, there are well-known analog techniques for obtaining solutions to two-point boundary value problems and to many two-variable partial differential equations. It is probably safe to say that almost all problem formulations and solution techniques commonly used in conjunction with analog computers can also be used in writing SCADS programs. Author