The manual describes two microcomputer programs written to estimate the performance of electrostatic precipitators (ESPs): the first, to estimate the electrical conditions for round discharge electrodes in the ESP; and the second, a modification of the EPA/SRI ESP model, to estimate the particle collection efficiency of the ESP operating with the electrical conditions predicted by the first program. Both programs, written in the BASIC computer language, are designed for the IBM-PC and compatible computers and the Tandy 2000 computer. The programs require Advanced BASIC and a color graphics adapter. The V-I program allows prediction of electrical conditions for both positive and negative corona and for arbitrary discharge electrode diameters and wire-to-wire spacing. This means that most commercial discharge electrode geometries can be simulated by proper selection of wire diameters and spacing. Both the V-I and performance models are completely documented in the report, including a discussion of the theory on which the models are based.