Well I dont know about three machines... in theory it should still work but in practice...???
If you use HDDriver then you can change the ID of the falcon by enabling SCSI processor device and selecting ID ? whatever.
I didnt do this though. I changed the ID on my adaptec 2940AU PCI to ID 6 from inside the menu. I think you can do this on most if not all adaptec scsi cards.
You dont need to do any tricks on your AMD, just put the scsi card in if its not already, and plug it into the drive. Leave the card on auto termination.
You may have to turn on the PC first or the Falcon. I have to turn on my PC so that the drive powers up then turn on the Falcon after windows starts to boot. I put the JAZ inside the PC but ran the SCSI cable outside to plug into the external connector because I could not reliably get the system terminated if I had the drive in the PC on the internal scsi connector and the falcon plugged into the external scsi connector on the 2940 card. It was prolly a mistake actually cos it worked fine anyway when everything was external to the PC, and I need to take the JAZ with the Falcon occasionally to the studio for recording drums, duh!!).