Abstract: An apparatus and method encodes alarm condition data and other data into the vertical interval signals of a plurality security television cameras so that the data may be used to determine which security camera pictures should be stored and retrieved. Television pictures including time and camera identification data are stored in digital format on the disk drive of a computer system. Pictures from multiple security cameras are selectively stored, even though the vertical interval signals of the various cameras are in general not synchronized with respect to one another. The contents of registers where the data is stored are updated field by field. The register updating operation is performed only during vertical intervals associated with each camera. Stored pictures and data are selected and retrieved from a data base according to predetermined criteria.