dual boot XP & 98

I’d like to dual boot XP & 98. I’ts easy to do by installing W98 first and then XP, but a training machine already has XP installed and I wish to install 98 installed as it seems to be more in demand at this point. I had a nightmare when I once installed 2000 after XP as XP got killed and I didn’t know what else to do so I reinstalled XP. I would rather not go through that again and I know the above can be done.
Any advice please?