Article View: comp.sys.mac
Article #33150Re: NeXT press release (very long but interesting)
From: Cory Kempf
Date: Thu, 20 Oct 1988 16:28
Date: Thu, 20 Oct 1988 16:28
24 lines
1759 bytes
1759 bytes
In article <73226@sun.uucp>, lyang%scherzo@Sun.COM (Larry Yang) writes:
> An audio CD has as its "format" basically one, long serial spiral
> (not unlike its vinyl counterpart). In computer applications, I believe
> the disks are usually formatted into wedges (sectors), not unlike its
> magnetic counterpart. Thus, along with the ECC overhead, there is the
> overhead for formating the sectors, labeling the sectors, etc.
A data CD (at least in the standards that I have used) is formatted
in a LONG spiral. the spiral is broken down into several blocks,
each of which "looks" like it is 2k. In reality, they use some
error correction code (ECC) that causes 8 bits to use up 14 bits
of space.
A CD-ROM holds about 660Mb of data after ECC, or on the order of
1 Gb without the ECC.
Unfortunately (at least from what I have heard), the Audio CD's (and
CD-ROM's are not compatable with the WORMs or WMRM drives. The Audio
CD/CD-ROM work on a laser reflection off of pits in the substrate of
the disc. (NB: when refering to CD's, disc is correct, not disk.)
--
Cory Kempf
UUCP: {decvax, bu-cs}!encore!gloom!cory
revised reality... available at a dealer near you.
Technical Details
Message-ID:
<169@gloom.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!husc6!encore!gloom!coryReferences:
<5423@juniper.uucp> <72886@sun.uucp> <635@ardent.UUCP> <73226@sun.uucp>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!husc6!encore!gloom!cory From: cory@gloom.UUCP (Cory Kempf) Newsgroups: comp.sys.mac,comp.arch,comp.sys.next Subject: Re: NeXT press release (very long but interesting) Summary: CD-ROM's use spiral track too Message-ID: <169@gloom.UUCP> Date: 20 Oct 88 16:28:45 GMT References: <5423@juniper.uucp> <72886@sun.uucp> <635@ardent.UUCP> <73226@sun.uucp> Sender: news@husc6.harvard.edu Followup-To: comp.sys.next Organization: Alloy Computer Products, Framingham, Mass. Lines: 23