Why do some GC discs from Datel have the CD logo printed on them?

[radorn]

It's been brought to my attention that some GC 8cm discs from Datel have the "COMPACT disc" logo printed on them.
I don't believe this means that these discs are based on CD tech, but the guy that pointed me to this thinks that must be the reason, reasoning that otherwise they wouldn't have put the logo on them.

I no longer have any of the stuff myself (which is why I'm not active here even though I have an account very much from the beginning), but I looked up some pictures, and indeed, the CD logo is present. Here are some examples I found:

Spoiler

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Even though I'm convinced that those Datel discs must be DVD-based, just like anything else for the GC, and that the logo is a red herring, the question remains:
Why is the official "COMPACT disc" logo printed on the discs? Are those discs actually based on CD tech rather than DVD and the GC still reads them? What's the deal?
Of course there are also other Datel GC discs that don't carry the CD logo: So are some of them CDs and the rest DVDs? Why don't those carry the DVD logo then? Could they be BluRays?

[Papy.G]

It may be that these really are Compact discs based, provided the GC's Optical unit can read them and the GC can boot off them, I don't have pressed CD Roms to test then, but SWISS is supposed to support ISO 9xxx aswell as some emulators. As a side note, I know it can't read CD-RW as I tried.

Datel programs shouldn't be that huge so they may fit on a 220MB media, think about it: the GBPlayer's boot disc program could even have fit onto a 1019 blocks memcard (provided Nintendo would have published a way of running programs off Memcards back in the days).

Maybe it was cheaper to press CDs than DVDs, at first, or maybe they just add the logo as an habit (which I think the most unlikely).


I had such a wonder but didn't feel like creating a thread just for that:
Does anybody knows about a project inside Nintendo to have double-density 10 cm game DVDs, as quite interrestingly, the GC case supports discs up to that diameter, that would have doubled the data capacity, and no big games have ever needed more than two 8cm DVDs.

[radorn]

Well, sure, IF they were CDs, 220MB would be enough to fit these programs. That'd be fine, if capacity was the only impediment. But that doesn't solve the problem.

My understanding is that the GC optical drive and media were a special modification of the DVD format that Nintendo comissioned to Panasonic/Matsushita in order to have their own proprietary discs for copy restriction and the usual media-based royalties that Nintendo bases their licensed developper business on.
There's absolutely no need for the GC drive to be backward compatible with CDs like consumer level PC optical drives do.

There's the case of the Dreamcast, where it's GD-ROM format is actually based on the format, just with double data density and some modifications to the layout. It even has a first session that's CD audio containing a warning for those that cluelessly put it in their hifi. And there's this other MIL-CD format that they planned to use for additional multi-media discs or something, and it ended being the main method to pirate games that killed the console.... Unlike that, the GC doesn't seem to have any kind of connection with the CD format, and, knowing Nintendo a little, I'd bet they were very specific to Panasonic that they should remove any traces of CD compatibility from the drive, as they have always been specially concerned about piracy, and for good reason, as they surely saw what happened to the Dreamcast.

I'm very skeptical that the GC could be coherced to read CD-based discs of any description, so I find it hard to believe that that logo printed on the Datel discs could be anything other than erroneous or misleading.

Does anyone have the facts about this? Are these discs are CD or not? if they are, how the GC can read them? if not, is there any good explanation for why the logo is there?

[Extrems]

It cannot read CDs and most of these aren't CDs.

http://redump.org/disc/64788/
http://redump.org/disc/68950/
http://redump.org/disc/57512/
http://redump.org/disc/54044/

[radorn]

@Extrems That was always my assumption, indeed.
So the first example contains PC software. And the rest are regular GC DVD-based GODs.

¿ Any clue why they slapped the CD logo on those anyway?

[Extrems]

I would guess Compact Disc has looser usage rules than DVD, as it cannot be advertised as a DVD.

They do use the DVD-Video logo on their DVD-Video discs.

[radorn]

Seeing as how they didn't use any format-related logos on other discs, I still find it strange that they slapped the CD logo on discs that weren't and couldn't be so.
Seems unecessary and the discs that don't carry format logos prove they didn't have to use them. Yet, there they are...

Oh well! Maybe someone knows the reason for it, however ridiculous it may be, or maybe those that know will take the secret to their graves
I guess it's not important, after all.

[SylverReZ]

Kinda strange how they slapped an unrelated CD logo on their discs, especially since the GC only reads DVD media.