Posted by Gene E. Bloch on 12/03/06 04:31

On 12/02/2006, aniramca@yahoo.com posted this:

[...]

> - When you buy a DVD movie from a store. Is it a DVD-R? It has the
> same symbol as DVD-R (The DVD+R symbol just a box with RW written on
> it).

Entirely different.

The data on (re)writable DVDs is almost literally burned by a laser,
which causes changes in the media to create data 0s and 1s. The data on
a commercial DVD (CD also) is pressed.

By a process I don't know much about, the data bits on the recording to
be are converted into pinholes for 0s and non-pinholes for 1s (or
vice-versa). This master with its pinholes is made into a negative mold
which is used to mold corresponding pinholes into a sheet of plastic,
and the sheet is then plated with metal and a protective layer of
plastic. Now you just have to add the label, put it into a box, and
sell it.

The above is correct in broad outline, but not exact in the details.

[...]

(Other posters in this thread addressed your other questions.)

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")

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