🚀 go-pugleaf

In article <1990Dec2.224254.28356@engin.umich.edu> ssave@caen.engin.umich.edu (Shailendra Anant Save) writes:

>   0> What is the format of storage of digital audio on CDs?  What is
>      the width ie. number of bits?  Per channel?

16 bits per channel

   1> What is the frequency of sampling (reading?) of the disk?

44.1 kHz

   1a> What does 4X and 8X sampling mean?

This is just a function of the player, not the disk.  It refers to the
use of a digital filter to do sample rate conversion to 176.4 or 352.8
kHz prior to D/A conversion.  This allows the use of a simpler reconstruction
filter (lowpass analog filter), which is used to remove the frequency aliases
above half the sample rate.  The simpler filter doesn't have as steep a slope,
and doesn't introduce as much phase distortion into the signal.

   2> What is the total amount of memory on a disk? 

It depends on how you look at it.  A lot of the disk is taken up by
error correction codes.  There is also subcode data that is used for the
time display, table of contents, etc.  CD-ROMs, which add additional error
correction beyond that of CD-Audio, are commonly spec'd at 550-650 Mbytes.

   3> What type of digital output do you get when you probe the 
      digital o/p pin on the chip or from the digital output of the
      player when available? Does it have start and stop bits? Must
      be serial.

Depends on the chip set used in the player.  Generally synchronous
serial.  There is no standard for signals inside the player.  There
are standards for digital audio interconnects.

Get the book _The_Art_of_Digital_Audio_.
--
Eric L. Smith      Opinions expressed herein do not necessarily reflect those
esmith@apple.com   of my employer, friends, family, computer, or even me!  :-)