A Structured-Data, Interactive Dynamic System Simulation Language Suitable for Mini-Computer Implementation

A data-structure oriented dynamic system simulation language which operates in a command mode is described. It is a highly modular, easily segmented language that lends itself to iteractive use. It is designed so that significant simulation problems can be solved on a mini-computer with as little as four thousands words of memory and nothing but a teletype for input and output. At current costs, interactive simulation of nonlinear systems, with graphical output, can be done using this language for as little as $2/hr, compared to $10 to $15/hr on a commercial time-shared computing system without graphics. The language has been implemented on a 8000-word PDP-7, using no peripherals other than a teletype and oscilliscope. Solutions of sample nonlinear problems are included.