Doesn't make sense to me.

Back in those days, the Apple OS was not licensed, since you needed a Mac to run it. You could literally go into an Apple dealership with a stack of floppies and create a new set of OS disks at no charge. I worked at an two Apple dealerships and people did exactly that. Later I worked at a company that supported 20,000 Macs, and they upgraded from vers 6 to version 7 of the OS with no licensing fees.

And you wouldn't boot and get a blank screen, you would see a white screen with the mac logo on it while it cycled through all the SCSI ports in order looking for a bootable drive. I'm trying to remember the message, but there would have been on saying that it could not find a bootable drive.