A typical track layout for a two-head helical VCR appears in Figure 21.16. Here we can see the video tracks slanting across the tape, shaded for head A, white for head B. At the edges of the tape, further tracks are present: the lower carrying a control track (serving a similar purpose to the sprockets in a cine film, and described later) and the upper carrying the sound track. Sound is recorded longitudinally in the same way as in an audio recorder, but with limited frequency response due to the low linear tape speed in the sorts of VCR we are dealing with. Tape is 12.65 mm (VHS) or 8 mm (Video-8) wide. It progresses at speeds between 22.4 and 10.06 mm/s, depending on format and mode.

Figure 21.16: Video tracks written by a two-head system, with each head writing alternate tracks. The relative positions of the sound and control tracks are also shown (VHS format)