[comp.ivideodisc] CD ROMS and Audio Cd Players

greenstr@cstw75.prl.philips.nl (Roland Greenstreet) (12/07/89)

Hi,

 I don't know if this is possible but maybe someone can help me. I have
been wondering if it is possible to connect an normal CD player , maybe with
some modification , to a IBM AT compatable to read CD ROMS. If this is 
possible what sort of interface would be necessary? I have seen something 
simualar done with an audio cd player being connected to two machines
one for the tracking and the other for sound processing in the Personal
Computer World magazine.

 On my cd player , a Technics SLP-2 , on the back there is a 'feature' 
connecter. This connecter has five pins in it. Is this of any help to
solving the above problem as I have no idea as to what it is for.

 If an manage to connect it all up is the data on the CD ROMS stored in a
special format? If it is does anybody know what this format is?

Thanks for Any Help

R.J.Greenstreet

blob@apple.com (Brian Bechtel) (12/08/89)

In article <806@prles2.UUCP> greenstr@cstw75.prl.philips.nl (Roland 
Greenstreet) writes:
>  I don't know if this is possible but maybe someone can help me. I have
> been wondering if it is possible to connect an normal CD player , maybe 
> with some modification , to a IBM AT compatable to read CD ROMS.

No.  Not without adding enough electronics to make the drive a CD-ROM 
player.  Note that you might also have problems with the duty cycle of the 
motors on a regular audio CD player; CD-ROM drives usually have better 
drive components to stand the increased seeking.

>  If an manage to connect it all up is the data on the CD ROMS stored in a
> special format? If it is does anybody know what this format is?

Most MS-DOS CD-ROM discs (and many Macintosh discs) are in ISO 9660 format 
(or its older predecessor, High Sierra.)  You can obtain a copy of the ISO 
9660 format from ECMA, the European Computer Manufacturer's Association.  
The address is
    ECMA Headquarters
    114 Rue du Rhone
    1204 Geneva
    Switzerland


--Brian Bechtel     blob@apple.com     "My opinion, not Apple's"

wheeler@osiris.cso.uiuc.edu (12/09/89)

For what its worth, I have a Apple CD ROM drive that plays CD audio while I
work :-}.  I know there are CD ROM drives that also play CD audio in the IBM
world (such as Hitachi).  There are two formats: 1) High Sierra (access by
DOS only) and 2) 9660 (available to both DOS and Macintosh).  Of course, I
don't know what the hell those two terms mean (hey I'm not paid to know 
anything, just to act like I do).
I know nothing! about your Technic's player.  Other than it doesn't have a
RS 232 port and thus it is probably not accessible by your AT.

gerry@zds-ux.UUCP (Gerry Gleason) (12/21/89)

In article <43000005@osiris.cso.uiuc.edu> wheeler@osiris.cso.uiuc.edu writes:
>
>For what its worth, I have a Apple CD ROM drive that plays CD audio while I
>work :-}.  I know there are CD ROM drives that also play CD audio in the IBM
>world (such as Hitachi).  There are two formats: 1) High Sierra (access by
>DOS only) and 2) 9660 (available to both DOS and Macintosh).  Of course, I
>don't know what the hell those two terms mean (hey I'm not paid to know 
>anything, just to act like I do).

This is another example of don't post if you don't know.  As someone else
noted, ISO 9660 is a later version of High Sierra.  I know that the ISO
9660 specification contains several levels that can be implemented, but
the highest levels may not exist yet in practice.  I originally thought
High Sierra was just another name for what ISO 9660 specifies, but it is
possible that it refers specifically to the first implementation level.

As to drives, I'm not aware of anyone using an interface other than SCSI
for CD-ROM drives, so we are talking about the same drives for both
Apple and PC compatibles.  I have experience with Sony, and Denon drives
that do have audio output, and LMSI drives that do not.  Even the Denon
internal half height drive has a miniature headphone jack and a volume
control on the front (I think they are unique with the volume control).

Also, a note on OS compatibility, ISO 9660 file system access is available
on UNIX also (your mileage may vary, we will have a released product for
386/ix and SCO soon, and I don't know about currently available products
for 386's or other architectures under UNIX).  The problem is that this
is not far enough for compatibility.  For example, we have been using
"Computer Library" CD-ROMs among others to test our file system.  Under
UNIX, you can access the files on the CD-ROM, but you can't run their
software that allows you to do searches, etc.  (Actually I haven't tried
to use it under Vpix, but I doubt it works, and it definitely wouldn't
work on a Mac.)  Furthermore, the license agreement is *very* restrictive
and probably doesn't even allow using another implementation of the
searchware with it (probably not because I haven't read it, but because
it doesn't explicitely forbid it, but parts of it seem like it could
and I'm not a legal expert).

Gerry Gleason

blob@apple.com (Brian Bechtel) (12/22/89)

In article <57@zds-ux.UUCP> gerry@zds-ux.UUCP (Gerry Gleason) writes:

> As someone else noted, ISO 9660 is a later version of High Sierra.

ISO 9660 is the international standard, with the first official version of 
this standard published April 15, 1988.  CDs pressed before this standard 
was approved (tried to) conform to a document called "Working Paper for 
Information Processing -- Volume and File Structure of Compact Read Only 
Optical Discs for Information Interchange," dated May 28, 1986. Discs 
following this standard are in "High Sierra" format.  This format differs 
from ISO 9660 in several places; for instance, volume descriptors have 
different type and quantity of fields. 

High Sierra is a different format, albeit slightly different, than ISO 
9660. By the way, the name High Sierra came from the hotel in Nevada where 
the first meetings regarding this standardization were held.

> I originally thought High Sierra was just another name for what 
> ISO 9660 specifies, but it is possible that it refers specifically 
> to the first implementation level.

Nope.  See above.

> As to drives, I'm not aware of anyone using an interface other than SCSI
> for CD-ROM drives

Amdek, LMSI (CM 201, CM 121), and Sony, among others.  It keeps the cost 
down if you're trying to target only the MS-DOS market.

In article <57@zds-ux.UUCP> gerry@zds-ux.UUCP (Gerry Gleason) writes:
> Also, a note on OS compatibility, ISO 9660 file system access is 
> available on UNIX also

ISO 9660 is supported by the Macintosh, Apple II, MS-DOS, VMS, various 
flavors of Unix, and probably most other serious operating systems.  
Contact your machine's manufacturer for further information.

You make an excellent point; reading the table of contents of a volume 
doesn't provide you with interoperability.  Just because I can get to a 
file, it doesn't mean I can make use of the file.  Having a common volume 
standard just removes one barrier from a long list of barriers...

> This is another example of don't post if you don't know.

No comment necessary.


--Brian Bechtel     blob@apple.com     "My opinion, not Apple's"