What is a program generator? It is an interactive software tool that translates the logic of a model described in a relatively general symbolism into the code of a simulation language and so enables a computer to mimic model behaviour.2 This facility gives the user the benefits of a simple symbolic input (especially valuable for use by those who are not conversant with programming practices) combined with the power of a high-level language in which to develop models of complex systems. Program generators for simulation have been available on mainframe computers since the beginning of the 1970s. With the advent of reliable FORTRAN compilers in the early part of this year, it has been possible to transfer the software onto 16-bit microcomputers. At the same time the development of intelligent bit-mapped graphics boards, for example the PLUTO system from IO Research, has made possible improved levels of model animation. Animation is a particular use of the topological information in a program generator. This paper describes a program generator, DRAFT, which has been transferred to an I.B.M. P.C. and shows how the technique has been extended to provide users with a low-cost, flexible and convenient method of generating model animation. The use of graphics standards has contributed to the power of the graphics support. With a program and graphics generator on a dedicated personal computer, it has been possible to animate a model of a robot system in 2 days, where the previous time for coding and the inclusion of graphics routines was of the order of 4-6 weeks. The animation requires modifications to the simulation support routines, in this case the SIMON library of FORTRAN subroutines. The analysis of this task has led to a modified SIMON/G library with a totally hidden graphics function. To invoke the animation facilities simply requires that the graphics support library is selected and that a graphics definition file is provided. This requires a minimal modification in the program generator, and consequently reliability is maintained.