Assuming I have changed cases on a Dell Inspiron 530s with the Foxconn G33M02-0RY007 motherboard BIOS rev 1.0.18, and set up all the correct power connectors, and have the bays available. Will the onboard FDC control only 1x3.5" drive, can I slave an extra 3.25 or even a 5.25 1.2MB to it for data recovery and retro gaming? BIOS only gives me the option of 1x3.25 as A:
FDDs cannot be daisy chained. You're better off getting a floppy drive controller card.
I assume you have the drives, because I wouldn't know where to find a 5 1/4" FDD.
On the contrary, 2 drives/cable to 1 Mainboard plugin, and I don't have anything old enough to run an ISA channel for a floppy controller card. PCI has DMA/IRQ issues with controlling floppies and there were never 5.25 IDE floppies made, only a limited run of IDE 3.5s from Sony, Teac, and I think Fujitsu instead of the standard MFM port, and SCSI floppies are cost prohibitive. I'm merely curious about whether the floppy controller on that particular Foxconn board will see a 5.25 1.2mb or not before i go dig one out of storage. i may be looking at picking up a 10-20$ Optiplex from the mid-late 90s to get the required onboard controller and slapping 98SE on it. I may try the gut a 3.5 USB and wire it to a 5.25 trick yet.
Some third-party boards maintained support for HD 5.25" floppy drives long after Intel/Dell dropped it - just about nothing from the major OEMs after about 1997 or so will support the 1.2 M floppy drives, though.
You'd need to look for something older than the Dell OptiPlex GX1 for that level of support.