Abstract: The present invention employs random electrostatic discharges to stress test electrical machinery, particularly digital computer systems running repetitive diagnostic programs. There is provided an interactive capability which allows the user to determine test duration either in terms of a fixed time or in terms of a specified confidence level, the latter case being one in which the system provides the user with an indication of the run time required. Significant improvements over deterministic "zapping" devices result. The improvement includes solving the equation: ##EQU1## (Where: ##EQU2## as a program step.

Abstract: A system having a computer, test control logic, an electrostatic discharge unit and a high voltage probe unit is provided for performing multiple, random, asynchronous electrostatic discharge testing of machines. The test control logic includes multiple, asynchronous, random, firing logic for controlling the states of a plurality of output lines which send control signals from the computer to the electrostatic discharge unit and the high voltage probe unit. The test control logic allows a user a preference of testing modes through an interactive input graph. The user may specify either a run time experiment or a specific probability of test coverage test.