Booting a 486 from floppy with the most up-to-date stable Linux kernel
Since I wanted to see how Linux would detect the drive that meant I needed to find a way to boot Linux. After a bit of googling I discovered the make tinyconfig option which makes a very small (but useless) kernel, small enough to fit on a floppy. I enabled a couple of other options, found a small enough initramfs, and was able to get it to boot on the 486. And as expected Linux has no problem with seeing that the drive is connected and the drive's full capacity.
Next step is to actually get Linux installed to the hard drive. I'd rather not roll my own distro but maybe I'll have to. Another possibility is to boot Linux from floppy and then download a kernel and initrd from a current distro and kexec over to it. But that feels to me like reinventing iPXE.
That's version 5.8 of the Linux kernel running on a 486. I shouldn't be surprised that this is possible, yet I'm still surprised this is possible.