I recently installed NT 3.1 (RTM) on a QX6850 @ 3Ghz. To my suprise, the PCI - IDE controller from Intel G41 chipset could be initialized by NT3.1 and everything worked out fine.
Now... I want to install 3.1 on my Ryzen 3900X system which is already fully compatible with NT 3.51 and 4, but not with 3.1. I use for NT 3.51/4 a VIA 6421 PCI-IDE controller which has it's own NT drivers or can be initialized via UNIATA.
For NT 3.1 it looks like I need a PCI - IDE controller with proper drivers. (actual NT 3.x drivers) Do you know any specific controller NT 3.1 compatible?