Actually, the original machine does have a floppy disc.
A floppy can be provided optionally to store settings made in Savage Quest, such as audio volume.
Couldn't tell you why they didn't just have those settings get stored to the hard drive. Probably just didn't want anything being written to it. Read only?
Anyhow, SQ will look for a floppy before continuing with the boot process, exactly like most PC's in the 90's did by default settings on the motherboard bios.
That's about all there is to it. You can read more about in the service manual.
The real machine will boot up just fine without a floppy. btw, I say again, there is nothing special about the bios on this motherboard. It's off the shelf hardware. The bios is not custom.