|I would try the 5.25 as a 1.2MB. |
The drive letter designation for the drive is dependent on where it is connected on the cable. If on the end of the cable (past the twist) then it will be assigned A. Below the twist will be B. My first PC had both and the 5 1/4 was the A. At that time most software came on 5 1/4 floppies. Also, the cable might work better if the 5 1/4 is on the top.
There is no purpose in having the floppy drive after the hard drive in the boot order. Any time you need to boot to the floppy it will be for something that needs to come before the others. Things like installing an OS that uses a start up floppy, or flashing the BIOS.
One other thing to note. The BIOS may not allow you to configure a 3.2GB drive. There were/are many different hard drive size barriers. I think yours may be at 504MB. Possible to either throttle with a jumper or install a drive overlay if that is the case.
I am not 100% sure about the end automatically being the A drive. I think that is correct. Been many years since using a 5 1/4 drive anywhere.