In article , Don Pearce
wrote:
On Thu, 4 May 2017 09:27:29 +0100, "Brian Gaff"
wrote:

Did they decide to make audio and video optical formats play from the
inside outwards? Was it simply due to the idea of making variable sized
discs? IE if you look at, for example early copies of James Last
Tango, or Roxy Music Avalon you see that there is a huge part of the
surface not used and it can be used as a mirror. Perhaps back in the
day, it was thought that one could crop off the disc so not only could
we have singles sized ones but old vinyl album length ones as well.

Nowadays of course the whole surface looks used even when its not.
Makes you wonder if there is some secret info in those outer areas....
Brian

By playing from the inside out, you can use multiple sizes of media -
that's pretty much it.

It also makes the initial track-and-focus lockup easier as any error angle
that causes the surface to waggle 'up and down' has less effect.

Jim

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