Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!amdahl!oliveb!cygnet!mark
From: mark@cygnet.CYGNETSYSTEMS (Mark Quattrocchi)
Newsgroups: comp.ivideodisc
Subject: Re: CD-ROM
Message-ID: <690@cygnet.CYGNETSYSTEMS>
Date: 14 Jan 88 21:41:52 GMT
References: <19898@teknowledge-vaxc.ARPA> <4469@watdragon.waterloo.edu> <2132@bloom-beacon.MIT.EDU> <4481@watdragon.waterloo.edu> <7990@e.ms.uky.edu> <4515@watdragon.waterloo.edu>
Reply-To: mark@cygnet.UUCP (Mark Quattrocchi)
Organization: Cygnet Systems -- Sunnyvale, CA
Lines: 34

In article <4515@watdragon.waterloo.edu> daford@watdragon.waterloo.edu (Daniel Ford) writes:
>In article <7990@e.ms.uky.edu> david@ms.uky.edu (David Herron -- Resident E-mail Hack) writes:
>>Music CD's do indeed use the same formats as Data CD's.
>>
>>Music CD's are single sided whereas Data CD's can be double sided.
>>
>>what I see properly.  On a Music CD there's a band of "smooth-continuous"
>>looking "silver" around the outside, inside that there's a band of not
>>so "smooth-continuous" looking "silver", inside that there's another band
>>of "smoth" stuff.  I assume that the data is in the not-so-smooth parts
>>and the smooth parts don't hold any data and can be used for labelling.
>
>The inner band of "smooth-continuous" silver has no data and is called
>the "lead in".  The outer "smooth-continous" area also has no data and is called
>the "lead out".  No labeling should go on these areas.
>
>The lead in starts from the centre to allow for playing different sized disks
>on the same drive.  I believe that there is now a CD single that is a bit
>smaller than the regular disc and holds about 15 to 20 minuties of music.
>
>>I had a thought.  Do WORM drives use the same data formats?  If not, can they?
>>I had this silly thought about making backup copies of my Music CD's :-).
>
>The two types of discs use different recording formats.  WORM drives use
>a CAV scheme just like magnetic disks and CD ROM uses CLV which is basically
>one long spiral track.  You could make a "backup" but the discs are so
>tough I wouldn't worry about it.
>
>In Japan they are marketing a hybrid disk that uses CD for sound and
>optical disk for video.  These little babies are used to sell music video
>singles.  Apparently it is a hot item.
>					Dan Ford
>

This is called the CDV format as was first introduced as 8" discs.