Terry Zagar wrote:

For the CD timelime, see:

http://www.ieee.org/organizations/hi.../timeline.html

A nice compilation. However, I miss computer based digital recording in
the mid 70s by Denon. I have a couple of vinyl records made from
digital recordings - 54 kHz sampling rate was used for that.

According to this, CD prototypes were demonstrated in 1977, and the
international CD standards group kicked off in 1978, and Philips was
pushing an 11.5 cm format disk from the start.

Yes, but it was a two sided CD, 2x60 minutes play time - if I remember
the discussion in the press at that time.

About SACD. At the end of the 80s the single bit converters appeared
on the market, both D/A and A/D. So in 1991 a company could have all
what is needed to record the raw signal coming off a single bit A/D
converter. I think, just the name was missing.

Norbert