[ Forwarded by Robbie Rhodes:

Robbie:

Thanks for the info -- I've seen a disc that large and something that
size is in the neighborhood of 200 or so tracks!   As to the discs with
projections (95% of all music box discs), they still have a hole which
is seen when the disc is held up to the light.

The largest projectionless disc is probably one by, I believe, Lochman,
which is for an orchestrion (32-inch??).  The trick for the discs with
projections will be in allowing for clearance of the projection so that
it doesn't scrape the photodetectors.

Again, many thanks and I'll try to get an email off to Ron Yost.

Jack