I was trying to recover some data from my old 5.25 floppy disks last weeks. First, I bought an old Pentium III 1Ghz, 256MB RAM for R$16 (about $7), and added my old 5.25 floppy drive to it.
The computer not had an HD or CD-ROM, but it has and old 3.5 floppy drive (very lucky!)
I installed FreeDOS on my old notebook HD first, to check if computer was working right. And yes, it was.
Now, I wanted to run Ubuntu Server 14.04 (because there is not enough RAM to run Ubuntu Desktop) to enable the USB and network interface, to make easy to copy the recovered files from and USB drive or network.
I did the install in a VirtualBox using another computer, and after installing Ubuntu Server, did a boot in VirtualBox with a Clonezilla image transfering it to PIII HD via IDE/USB interface.
After installing it back to PIII, the first problem was Grub UUID.
I fixed it booting on Grub recovery in Ubuntu, and running the command:
$ sudo grub-install --recheck
By default, the floppy module is not loaded first time, to fix it:
$ sudo modprobe floppy
Next annoying thing, which I lost almost 2 weeks trying to fix it, is the 5.25 floppy drive motor spinning forever bug.
When I try to access the drive, using mount or dd, the drive motor turns on and never turns off, ever.
Finally I found a workaround to fix this!
First, install fdutils:
$ sudo apt-get install fdutils
Now, add this line to your /etc/rc.local:
floppycontrol -C 2147483647
Reboot, and your 5.25 floppy drive is working!