I’m creating this thread mainly to have a handy link. There is some info about this topic in the FAQ, but not enough to my taste when I want to direct someone to some relevant reading.
For most regulars here, there is nothing new in this first post, but for many newcomers some of this info will come as a surprise, due to the huge amount of misinformation about this on the net.
Discussion is of course open, and don’t hesitate to suggest corrections: I may myself have some misconceptions, or I may have forgotten some relevant info
@Arachne and Dragemester: after discussion and corrections, this post could maybe be appended to the MEDIA FAQ, what do you think?
A persistent Internet myth, apparently instigated by online shops, is that the mediacode (also called ADVINFO or MID) of a disc (TYG02, MCC 004, RITEKG05…) only refers to the dye used when making the disc, as if the mediacode was merely the name of a given dye.
A correlated misconception seems to be that brands make their own discs, using this or that “dye” in the process, and that this dye used is the only difference between discs in terms of characteristics.
These misconceptions often lead to confusion when discussing media quality, because those who have been extensively exposed to these myths, and those who know better, often take some time to realize that they’re not referring to the same thing when talking “dye” or “mediacode”!
Here is the truth:
1. Most brands don’t make their own discs.
There is actually a stunningly little number of discs manufacturers compared to the huge amount of brands available.
Memorex, Ridisc, Datawrite, Rimedia, have never made any optical disc. They just put their brands on blanks they buy from a manufacturer.
TDK, Fuji, Sony, Maxell, Ricoh have been making their own discs for quite some time (this has changed recently).
The majority of discs available on the market are actually made by CMC, Ritek and Prodisc (Taiwanese manufacturers), or Moser Baer India. The other manufacturers have much smaller market shares.
2. The mediacode refers to the specific model of the disc and its actual manufacturer.
This includes the dye indeed, but also the reflective layer, the type (+R/-R), the manufacturing technology, everything. Even the polycarbonate used!
TYG02 refers to Taiyo Yuden 8X -R discs. Even if you find this mediacode under the Verbatim, Datasafe or Plextor brands, these discs were actually manufactured by Taiyo Yuden in Japan, with Taiyo Yuden technology.
MCC 02RG20 refers to Mitsubishi Chemicals (MCC) 8X -R discs. Even if you find this mediacode under the Datawrite or Infiniti brands, these discs were actually manufactured using Mitsubishi Chemicals technology by one of the authorized MCC manufacturers (though to add to the confusion, Mitsubishi outsources the actual manufacturing to other companies’ facilities, but that’s another story).
3. A same dye may be used by different manufacturers to make different disc models with different mediacodes.
A manufacturer producing/formulating a given dye may sell this dye (or its formulation and manufacturing process) to other manufacturers.
Example: RITEKM02, which used a Mitsubishi dye, the same that Mitsubishi themselves used for MCC 01RG20. But the manufacturing technologies and mediacodes were different and, despite sharing the same dye, these discs were pretty different in their characteristics and each needed to have its dedicated burning strategy in the burner’s firmware.
4. The purpose of the mediacode is mainly to tell the burner’s firmware how to burn the disc.
A burner firmware has burning strategies (burning speeds, methods like CLV or CAV, laser power…) for most disc models existing on the market, assuming the manufacturer of this disc model provided the necessary info and samples to the companies making the burners.
This is one of the reasons why there are faked mediacodes around. Some manufacturers (mainly in Hong-Kong) don’t have (or don’t want to develop) the necessary resources to provide the burners makers with the info and samples so to have a dedicated burning strategy in the burners firmwares. So they use a mediacode from another company to fool the burner (and, incidentally, the customer).
Now that you know the truth, spread the knowledge, and don’t hesitate to bother the online shops by telling them they are wrong and they are spreading misconceptions