IEC 61834-1 pdf download.Helical-scan digital video cassette recording system using 6,35 mm magnetic tape for consumer use (525-60, 625-50, 1125-60 and 1250-50 systems) 1 General 1.1 Scope This part of IEC 61 834 specifies the content, format and recording method of the data blocks forming the helical records on the tape. It describes the common specifications for cassettes, modulation method,...