VSim offers a text-based setup for simulation in addition to its visual setup method. Rather than constructing a simulation through a graphical interface, the text setup allows the user to directly access the text-based (.pre) input file instead. Though this method requires the user to have a more thorough knowledge of the simulation grid, field properties, and other general characteristics governing the simulation, it also allows the user to combine fields and particles in unique ways. It also allow one to use some features that are currently not available through visual setup.