When Ampex developed the quadruplex magnetic tape video recording system in 1956, it had certain limitations, perhaps the most important of which was the lack of pause or still frame capability, because the picture signal was segmented, or broken down into discrete segments to be recorded on the tape individually (only 16 lines of the picture in each segment). Thus, when tape motion was stopped, only a single segment of the picture recording was present at the playback heads. The helical-scan system overcame this limitation.