In this paper, we demonstrate phase based Boolean computation by simulating functional blocks using a circuit model that is based on the measurement data of GeTe6 oscillators. The oscillators are fabricated and characterized with a resistor and transistor ballast. We demonstrated, for the first time, usage of a transistor ballast in the subthreshold region for low power operation. Functionally complete logic gates for phase-based computation were simulated using SPICE. Finally, a full-adder was simulated as a proof of concept.