Abstract: An optical storage system achieves high density, sufficiently high to permit both video and audio to be stored on a compact disc, or to store other data at very high density. Pits are encoded on the disc storage medium with respect to timed electronic reference signals (not simultaneously optically encoded on the disc) which divide each revolution of the disc into a multiplicity of equal spaces or references. The pits have leading edges on the leading side of a reference signal and trailing edges on a trailing side of the reference signal, so that each pit staddles a reference signal. The length of the pit leading up to the reference signal represents one sample of information, while the length of the pit from the reference signal to the pit's trailing edge represents another sample of information.