A data separator circuit for use in decoding single density encoded data retrieved from a floppy disc, the circuit comprising a phased lock loop edge aligning circuit in combination with logic circuitry for providing a first output of separated data and a second output of the separated clock signals. The separator circuit generates an approximately periodic data window which is held in phased alignment with respect to the approximately periodic clock signal, the data window being utilized to gate out, or separate out only the single density encoded data.