11/19/1984 at 01:00 AM EST
On VHS machines you can record at three speeds: fast enough to fit two, four or six hours of programs on the same T-120 cassette. At the six-hour speed you give up a barely noticeable bit of picture quality, but you get more on a tape. You'll see VHS machines advertised promising eight hours on a tape. Don't be fooled: That's not a function of the machine but of the tape. To get eight hours you need a thinner, more fragile, more expensive tape. Beta machines can record up to five hours. And 8 mm will come with a top time of only 90 minutes.