Abstract: An improved test system for performing DC and AC parametric and dynamic functional testing of multi-terminal integrated circuits is described. All of the circuitry for producing and responding to D.C. and high-integrity stimulus and response test signals is located within a Test Head module sized for use in close proximity of the device under test. A high-integrity bus in the Test Head interconnects the high-integrity producing and handling circuits, with inexpensive connectors and batch-fabricated printed circuit board techniques. A Controller provides digital test commands for energizing the test signal producing cirucits within the Test Head and for evaluating the test results. The control and measurement signals passing between the Controller and the Test Module require no special conductor implementation techniques.