Quad recording [1] preceded helical. In Quad, the mag stripes are across the tape almost perpendicular to the tape's movement. The head spun at an insane speed

Quad recording [1] preceded helical. In Quad, the mag stripes are across the tape almost perpendicular to the tape's movement. The head spun at an insane speed -- 14,400 RPM in open air. Helical was originally invented as a lower-cost recorder. Once helical gained the ability to do slow-mo and still-frame, Quad died. https://en.wikipedia.org/wiki/Quadruplex_videotape https://en.wikipedia.org/wiki/Quadruplex_videotape