Phil Allison wrote:

D.M. Procida wrote:

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And it is remarkable, but also galling, that my
£20 USB optical drive can reliably read anything I put in it, while the
hi-fi CD players in the house that I spent considerably more on will
reliably refuse to play certain discs (and not all the same ones in each
case).


** CD players are unsurprisingly designed to play audio CDs made to the
original 1982 Red Book standard. Such disks carry the rectangular logo:
"Compact Disc digital audio".

OTOH optical drives are built to a later and very different standard that
allows different laser wavelengths, higher speeds, finer track pitches and
smaller pit sizes.

It should be no surprise the latter will play non standard audio CDs.

Such CDs should not carry the rectangular logo but rather have a warning
to be played only in machines equipped with modern optical drives.

I'm talking about standard audio CDs.

Daniele