What has you stuck in 32 bit mode? If it is "really old computer" there may be other issues that would prevent you from having it all work. It looks like that might be a PCI card model. That also suggests SDRC would maybe work but only in a rather constrained sense if you have more memory than typical for computers of that age.

All might not be bad, though. I believe there are PCIe to PCI adapter cards just as there are PCIe extension cables for PCIe cards mounted at odd angles for airflow. Performance would still be a little constrained by SDRC standards. It sounds like the radio is built around an audio ADC.

Good luck with it.

{o.o}