Thanj you Li for your effort.
As it happens, I did finally find the 1394 Host Controller. It was hidden by Windows (Device Manager-View-Show hidden devices). One chapter in
www.studio1productions.com/Articles/Firewire-1.htm led me to this find. Can't recall which chapter and sentence,
Unfortunately the info I got from the host controllers was that the cable should be reconnected. No joy there. After a lot of troubleshooting and investigating, I stumbled to a video in Youtube (How to use legacy FireWire and Thunderbolt devices on new PC's with Thunderbolt 4
by
Scott Schramm) that gave me the answer. With my 12 gen Intel cpu (i9-12900K) i will not be able to connect Firewire to my pc. Period. There. Have to refurbish my older pc...