AmigaOS video modes question

@All

I have currently a hard time understanding how video modes work on AmigaOS4.

There is "PC" and no "PC" video modes. As far as I remember, "PC" video modes mean "little-endian" and no "PC" mean big-endian (so how the color bytes placed in memory).

Now, what I didn't understand, why for x5000 with RadoenHD I have that:

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But on my pegasos2 with Radeon9250 i have that:

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See, on x5000 with RadeonHD, 16-bit modes are "PC" ones. On pegasos2 with Radoen9250 16 bit modes are not "PC" ones. Is it simply typo, and in both cases 16 bit are "PC" (so little-endian ones)? Or indeed RadeonHD in 16 bit are "little-endian", and Radeon9250 are "big-endian"? It can be typo probably? And visually, it all works the same in 16bit modes on both RadeonHD and Radeon9250, meaning that probably with Radeon9250 "PC" over 16bits just not written, but mean it?

I agree. :)

I saw these "PC" modes first with the Mediator Voodoo drivers, which supported both, at least eventually. Did the Mac firmware Radeons at the time (PowerPC based platform which was BE, the platform not the chips) use big endian? I remember those cards are not supported on OS 4. So I think the card firmware determines the pixel format. Since OS 4 didn't have legacy "native" software, big endian format was easy to drop.

@kas1e

Yes, PC means little-endian byte order. Older Radeon cards (like the Radeon 9250) are fully bi-endian, whereas the latest cards are not. Hence, your Radeon 9250 can do big-endian 16-bit, while the Radeon HD card in your X5000 can't.

Hans