At 02:46 AM 99-10-29 , you wrote:
>I am considering buying a CD "burner."  I've been reading conflicting
>information about CD-RW vs. CD-R.  One article said that a CD recorded
>on a RW is only usable on the computer that has that burner.  Is that
>true?  Are there any problems associated with CD-RW and CD-R drives as
>far as using them on a different machine.
>
>Byron Wolter
You're opening a can of worms with this one! I'll try to summarize:

Physically:
Any CD-R or CD-RW written on a machine can (usually) be read by that
same machine. Possibly not the CD-ROM drive, but almost certainly the
burner.

Any CD-R written on a machine can be read on most, but not all CD-ROM
drives. CD-R's do not reflect the same amount of light that pressed(store
bought) CD's do, so some drives, usually older ones have problems with
them. There isn't much you can do to stop this; the older drives are
simply not able to pick-up the reduced amount of light reflected.

Any CD-RW written on a machine can be read on any newer CD-ROM drive
that supports MultiRead(notice the capitals?). The drives that support
MultiRead are newer, usually at least 24X. Some drives that do not
support MultiRead can read CD-RW's, but this is not a sure thing. Basically
if the drive works, great, if not, there's not much you can do about it. The
reason here is also the amount of light reflected, except CD-RW's reflect
even less light then CD-R's.

 From a software/logical point of view:
CD-R's and CD-RW's can have several formats. Some are standardised, like
ISO-9660, and most computers with CD-ROM drives will read these without
any additional software or drivers. This includes non-PC's, for example, with
ISO-9660. One other format that can be read without drivers on Windows PC's
is Joliet. Both of these formats are written using mastering software, such as
Adaptec Easy CD-Creator. Basically, if the drive can read the CD at all,
the data
can be read off the disc.

These disks must be written in one go, from start to finish with no break
due to
the way CD-R(W) drives and this software works together.

Other formats for CD-R's and CD-RW's make the CD-R(W) seem like a giant floppy
disc to the user. One such program is Adaptec DirectCD. It(and most similar
programs)
use a form of Packet Writing to write small chunks of data. These discs are
special
cases.

I'll write about Adaptec's DirectCD, as that is the software that I know.
CD-R's
written with DirectCD can only be read(and written to)on a CD-R(W) drive until
they have been closed to ISO format. This ISO format is the same type of
format(with a few modifications to allow for fragmentation) as used by
mastering
software. Until they have been closed, no CD-ROM drive will read the data
on the
disc. _There is no way around this._

CD-RW discs written using DirectCD can be read and written on the burner, but
they can also be read on CD-ROM drives that support MultiRead. These systems
need to install a free reader, called the UDF Reader to read the disks
first, but once
this has been done, they can read any DirectCD formatted CD-RW disc. Many
newer CD-ROM drives now are supported by the UDF Reader, so if the drive
can read the CD-RW, chances are pretty good that DirectCD formatted CD-RW
discs can be read using the reader.

There is other software available to do the same type of thing as DirectCD from
Adaptec, one such is called PacketCD, but I don't remember who the
publisher is.

This is a (brief? well, I tried :) summary of the conditions. I have left
some things
out, like multi-session discs, but that can be left until after you buy.

I hope this helps.

Jamie Furtner
-- Jamie Furtner [log in to unmask]

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