Pentium board used to have PCI-ISA bridges..

https://www.science.unitn.it/~fiorella/guidel … tlk/node69.html

This worked, because the PCI buses in these early PCs had the ISA address space reserved.
The bridge then mapped the atrached ISA slots back into the original ISA memory regions.

Not sure it this still works out of box with modern PCs, too, though.
I mean, PCIe looks like PCI to software. But I don't know if PCIe still supports the ISA address space.

The topic of ISA crops up from time to time, and I wish I had bookmarked some.
The problem, if I recall correctly, is that the below 16MB address space is no longer available for the pcie space, and thus also not for the pci or isa space.
Virtualization should be possible, direct hardware access not.

edit: and FYI, the PCI on that supermicro board hangs off the PCIe bus. Chips are located on the underside of the board.

1 can you even load non signed drivers in spyware 11?
2 afaik PCI to ISA is not possible for full compatibility, thats what SB-Link and DDMA were for
3 ISA was replaced by LPC, but even LPC cant fully replace ISA https://flaterco.com/kb/ISA_chipsets.html#intelind
4 just buy USB FDD, or if you need something other than 3.5 get a https://github.com/keirf/Greaseweazle https://www.youtube.com/watch?v=F3uvuCrcF2Y