The present invention is a system for accurately phase locking two signals having the same frequency but which are of arbitrary wave shape, and which can be at very low or at substantially higher frequencies. Elements of two signals are stored at sequential address locations in a pair of ROMs. An oscillator drives a counter which provides a sequential address output signal, which is used to address the first ROM. A binary signal which can be generated from a manual control calibrated in 360.degree. provides a phase control signal which is added to an address signal generated from the same oscillator, and which is used to address the second ROM. The increment between the two ROMs established from the control provides control over the phase differential between the two generated signals. Since the addresses of both ROMs are generated from the same oscillator, their frequencies are the same, and their phases are locked at the desired phase differential.