I try to go to open firmware on my iMac but it just shows the no OS screen
Earlier Mac models
Use Option-Shift-Command-R to start Internet Recovery, which works on most Intel Macs starting with macOS 10.12.x. If your Mac is even older, you need to know the exact model and create a bootable installer for macOS on another Mac that is suitable for your Mac model.
Yes, knowing the exact iMac model would help.
Sorry for the late reply
Well, I was actually just trying to boot from a USB with linux on it because I don't have an OS installed on this imac and I want to use it / experiment with it again. But apparently (according to ChatGPT) this iMac is too old to have something like a boot menu or recovery mode (the fact that command + R or option) while starting it does nothing
Please describe what you would like to accomplish. Start from the beginning. Discuss this open firmware you seek. Avoid the XY Problem.
Booting iMac from USB
