Abstract: A method and apparatus are disclosed for generating simulated waveforms for testing the operability of a vectorcardiogram (VCG) machine. Three distinct waveforms are provided which generally simulate electrical activity within the human heart along three separate axes. Preferably, the waveforms are generated from a single electrocardiographic reference signal. The apparatus includes a plurality of connectors which are selectively coupled to the waveforms and supply output signals to the VCG machine which correspond to waveforms which would ordinarily be supplied by a plurality of electrodes attached to a live patient at various positions.