In article ,
Jim Lesurf wrote:
In article , Dave Plowman (News)
wrote:
The Compact Cassette was introduced as a mono format for dictation
machines, etc. Philips were sensible enough to allow it to be used
under license but free of charge. But did retain a degree of control
over the basics.

I'm not sure if this included the use of Dolby B or not. But did over
the basics like speed.

IIRC They mandated aspects like the physical dimensions (inc. things like
track widths and spacings), but I'm not sure about which 'electronic'
details they might have defined or limited.

Yes. But then they probably couldn't guess what might be developed down
the line. Like Dolby B and much better tape.

They did try to flog their own 'noise reduction' (DNS?) system which was
single-ended. But I don't recall that they could (or attempted to) block
or control the adoption of Dolby. If nothing else, they couldn't have
stopped anyone from buying a Bolby adaptor box, anyway! Given how good
Dolby was they probably twigged quite quickly it would be good for
sales, and hence their own deck/cassette royalties!

Ah - of course. DNS.

I've a feeling that the majority of music cassettes with Dolby B were
actually listened to - in the car etc - with Dolby switched off. ;-)

--
*Why do the two "sanction"s (noun and verb) mean opposites?*

Dave Plowman London SW
To e-mail, change noise into sound.