DVD-R and DVD+R

[charlie_ps2]

General Information
As with CD-R, DVD-R/DVD+R (DVDR) uses an organic dye polymer that reacts to around 10 milli-watts recording power. Because DVDR holds around 7 times CD-R capacity the laser wavelength is shorter (650nm red against 780nm infrared) and the DVDR recording lens has a nominal aperture of 0.6 against CD-R of 0.5. These two factors combine through the higly focused red laser beam to produce opaque burned marks as small as 0.44um as compared with 0.83um on CD-R.

The dye polymer is coated onto an optically clear polycarbonate substrate that has a microscopic groove (known as the pre-groove), 650nm deep, formed as a spiral track across the surface. Behind that a thin layer of reflective metal is sprayed and then optically clear protective layers are applied to form the disk that we see.

For recording, the tightly focused (on the pre-groove) laser beam heats the dye polymer, permanently altering its state (to opaqueness) such that microscopic marks are formed in the pre-groove, the length of which depending on the time during which the laser was turned on. These marks correspond with the raised portions of a pressed DVD and are thus non-reflective or insufficiently reflective (provided that laser burning power was adequate) to register upon reading.

For reading, the areas between marks, not being opaque, are reflective when a tightly focused laser beam of much lower power at 650nm wavelength is sent to the pre-groove.

Data is then streamed by noting the transition from reflective to non-reflective and the length of time to the next transition. A digital-to-analogue decoder then converts this 0/1 stream to data as we know it

So the critical factors that enable a DVDR to be accurately read (assuming a clean lens) are:
a Sufficient power to burn opaque marks
b Sufficient precision to burn marks of the correct length and with sharp edges
c Good quality dye polymer to enable the above characteristics to apply
d Sufficient precision in the reader to correctly stream what was correctly written
e Sufficient power in the DVDR read laser to meet the reflectivity characteristics of the DVDR

The relevant ECMA standards require the read laser to accommodate reflectivity in the range 45% to 85%. If the media doesn't make it into this range, then there s no guarantee that the DVDR will be readable. Reflectivity is a function of the metallic layer and the optical clarity of the protective layers.

Competing Standards
DVD-R
This format sort of "came first" governed by the formal standard ECMA 279 (http://www.ecma.ch/ecma1/stand/Ecma-279.htm). All DVD-ROM drives are supposed to be able to handle DVD-Rs burned to this standard and thus within the correct reflectivity range. Sony would calibrate their lasers to work within the 45% to 85% range. DVD-R can burn at a maximum of 2x.

Without going into too much detail, DVD-R uses pre-set sector address information that synchronises at write time. This is the reason why burning speed is constrained to 2x because this has to be read and synchronised.

DVD+R
This is a competing standard backed by Philips, HP, Sony, Yamaha and Ricoh. The essence of DVD+R is its first incarnation as DVD+RW (ECMA 274 http://www.ecma.ch/ecma1/stand/Ecma-274.htm). DVD+RW uses a wobbled groove the count of which replaces the DVD-RW sector address synchronisation during the burn process. DVD+R is the write-once version, also with a polymer dye so that the burned result is narly identical with DVD-R. The "nearly" term reflects the fact that newer read laser mechanisms are more accurate and can resolve the small differences between DVD-R and DVD+R arising from the fact that DVD+R can be burned at 2.4x because of the wobbled groove.

This means that DVD+R can theoretically be read on any PS2 with a good quality/condition laser, such as the v5 and it has been reported as successful on a v3 - though not many v3s these days have new condition lasers!

As ever, this information is provided at your own risk to use.

[h90]

Today I tested a v5 and a v3 (day of release purchased in Europe) and very hard used (neo 2.0 with 1 microfarad capacitor, laser turned on more) from children all the time. After installing a original messiah, it could read CD+RW without any problems, like Originals!

Michael
www.psxtune.com

[charlie_ps2]

That's a "second" if you played CD+RW on a v3. I've heard of just one other person accomplishng this and with DVD+R as well. It's not impossible - it just requires the laser to be right.

[h90]

Now I am at 3 v3, 1 v4 and 1 v5 PS2 without problems on DVD+R
All with our original Messiah.
The DVD+R I got from a customer was made with a Philips on Philips DVD+R.
One v3 wanted to see the DVD+R very near and scratched it with the laser eye. But after a very minimal adjustment it worked perfect. But this PS2 was in very poor conditions.
Michael
www.psxtune.com

[5150]

charlie_ps2, I'm from Sao Paulo, Brazil.

I've found your information very useful and I have a question?

Can I translate your text to Portuguese and post it in a Brazilian forum?

thanks, and keep up the good work!

cya!

[salman.a]

does ps2 v7 play dvd+R please let me konw thanks

[Don6323]

Yes it does salman.a my v7 seems to like the +R disk better than the -R. I installed the magic 2 a couple of weeks ago and seemed like it only would boot first time using sony +R media memorex tdk imation all would take 2 or 3 taps of the reset. So I opened it back up and adjusted the laser. This guide realy needs to be updated charile since the values and pics don't reflect any current PS2. The default values were 1100 ohms for the pot on the left and 1500 ohms for the right. I lower both by 100 ohms now everything boots first time. I don't know if this will cause my laser to burn out quicker but this was not a large ajustment so I should be ok.

Hope this helps


Don

[salman.a]

Thanks Don.
I have my ps2 v7 in for installation. The installer installed it but it wouldn't load the games. I gave him another ps2 and he is currently working on it. Are the new p7 need the laser to be adjusted or something else is wrong with the units. Please let me know. Thanks again guys.

[Don6323]

Have you tried non DVD PS2 games this will tell you if the install is good if it boot a cdr PS2 backup. If this cks out look to charlie for the optimal setting of the pots on a v7 since he has done many installs.

Post what the factory settings are for yours. I read somewhere in this forum that the pots are all over the place on the v7 units.

Don6323

[Kemikals 2003]

DVD+R has a better loading rate than DVD-R. I have had this issue as well. I am now resorting to backing up on DVD+R media for my PS2 DVD games.

The only DVD-R media that does not give me problems is the Meritline DVD-R SilverTop.

Other than that the Memorex DVD+R has been loading each and everytime. (From standby - double tap the RESENT button to load a DVD+R media)

S.

V7 PS2 w/ M2 V7