I have a old version of Bitcoin QT on Apple Which I think is about 3 years plus old but it was on my old computer which died. I have now recovered the drive at the bitcoin-qt application but it won't run on my current computer either due to the operating system or some other issue. The problem is that I don't have the wallet.dat files as I never generated that back on my old computer, so really need to run the old application in order to generate the file. Any suggestion on how to proceed? Is this an issue of finding an old version of the operating system and run the application file there or what other approaches should be taken?

Any help would be much appreciated
I don't have the wallet.dat files as I never generated that back on my old computer


It's not clear to me what you mean by this. There is only one wallet.dat file (plus any backups for safety). It starts empty when Bitcoin QT (currently Bitcoin Core) first runs, and after that the wallet.dat file accumulates your Bitcoin transactions which determine its bitcoin balance. The transactions are stored in the blockchain, which Bitcoin QT initially downloads from peers on the internet and then subsequently updates whenever it is running.

It seems that you cannot boot from the old drive. Can you access it at all to see and possibly recover files from it?