A two-value, zero-delay simulator that computes signatures and analyzes fault coverage for circuits with built-in self-test (BIST) is described. The simulator, called the compiled logic simulator (CLS), is used with a monitor that simulates BIST control logic at a high level. The simulator's compiled code is well suited to the IBM 3090 pipeline and fault simulation using flat random patterns. The linear-feedback-shift-register simulation monitor is discussed. Performance results are presented. Fault simulation with one million random patterns on a 40000-gate circuit was done in 16 CPU minutes.