Yet many of these self-booting disks would quite happily work when copied to a reboot-persistent RAM drive (the RAD: drive), which showed that although it was c

Yet many of these self-booting disks would quite happily work when copied to a reboot-persistent RAM drive (the RAD: drive), which showed that although it was claimed that they did all the OS-ey things themselves, actually there was still quite a lot of the original OS still running there. At the core of it, the AmigaOS exec was tiny and helpful, and things like device drivers were just separate processes that you sent messages to, so it would make sense to make use of them, but just not bother loading all the other stuff that makes up an OS.