@balaton
Quote:
and this may be a problem because this card surely has no AtomBIOS so may need its own ROM to run.
PCI Radeon gfx cards (ATIRadeon.chip driver on AmigaOS) don't have an AtomBIOS, only the old x86 BIOS which is emulated by the x86 emulators of U-Boot, CFE, SmartFirmware or the x86emu.resource on classic Amigas.
Only the newer Radeon HD/RX gfx cards (AmigaOS gfx drivers RadeonHD.chip and RadeonRX.chip) have an AtomBIOS.
Your X550 is a very special case, nearly all gfx cards supported by the AmigaOS ATIRadeon.chip driver are PCI gfx cards, a few of them are AGP cards, but none PCIe ones. At least none that I'm aware of that has already been used successfully with AmigaOS.