  We describe a portable CCD-based instrumentation system designed to
efficiently undertake high time precision fast photometry. The key components
of the system are (1) an externally triggered commercial frame-transfer CCD,
(2) a custom GPS-derived time source, and (3) flexible software for both
instrument control and online analysis/display. Two working instruments that
implement this design are described. The New Zealand based instrument employs a
Princeton Instruments (PI) 1k x 1k CCD and has been used with the 1 m telescope
at Mt John University Observatory, while the other uses a newer 1k x 1k
electron-multiplying CCD supplied by PI and is based at the University of Texas
at Austin. We include some recent observations that illustrate the capabilities
of the instruments.
