On 30/04/2014 11:17, Dave Plowman (News) wrote:
It makes no difference. The maximum playing time was dictated by the
mastering machine of the day.

Actually given the disc size and laser frequency it's pretty well
limited to what they had. That's why no-one has really squeezed more
than 80 minutes in - the squashed tracks give errors.

It's carefully designed so that the first diffraction fringe of the
laser falls in the gap between the adjacent track and the one after.

Andy