Modern interferometric measurements have evolved beyond simple interference fringe tracing to automatic phase measurement over large data array sizes. Through the use of video digitizers and inexpensive PC computers, phase shifting interferometry has become fairly commonplace, with various commercially available instruments on the marketplace. As data arrays grow in size, the number of calculations increases to where the PC computers are stretched for performance. Real time manipulation and display of results are beyond the capabilities of even workstation class computers. In response to the desire to rapidly manipulate large data sets from interferometric measurements, special electronics were developed to operate in conjunction with a high performance interferometer to aid in the testing of large optics.