Re: [ARSCLIST] Audio History In a Nutshell?

["Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>]

At 11:17 PM 2007-12-06, Steven C. Barr(x) wrote:

> Question...! Am I correct in assuming that the actual digits to which these
> pointers "point" are NOT the actual audio content as sampled each 44.1th
> of a second...but, rather, digits which have to be converted (digitally)
> to those "sonic content" bits?

At some point, the drive handles the error correction codes. In 
CD-ROM there are only error correction codes, whereas in CD-A there 
is also an error concealment option if the error is uncorrectable.

At the output of the drive on the multi-wire ribbon cable, you are 
getting bits/bytes of audio or files as you see them. The scrambled 
data on the CD (interleaved and coded) is internal to the disc and 
the related drive, as I understand it, the computer doesn't have to 
deal with the drive overhead--this is the same in hard disks as well.

One might say there is a layer (layers) of indirection between the 
electrical I/O of the drive and the bit patterns on the optical 
media. Without these PROMs, the optical media is useless, 
effectively. This is one of the challenges down the road of reading 
these formats. No players, no read...or you can dig up the old 
literature and re-engineer the silicon, I guess. Right. Save some drives.

Cheers,

Richard


Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.