You can use virtual machines to run D1 on modern systems.I've actually been playing occasionally over the past weeks. Sadly, the hardest part is making it work on modern computers. I couldn't get it playable at all on my new Win8 laptop. I tried every sort of compatibility mode option, but was never able to make it display properly, or not crash randomly, and couldn't make multiplayer characters at all.
I've been playing on my less new tower when I do play, running Win7 and it works fine.. but only d1 v1.0. If I update to v1.09 the colors get corrupted into neon hues and I can't find a way to fix it. (Even on v1 it snaps into neon every now and then, but fixes if I change dungeon levels or alt-tab out.) And I can play MP there, but unfortunately auto hotkey won't work (It will work if I play v1.09, but then the colors are arsed). I don't think a mage is playable without properly mapped hotkeys, so I'm limited to occasional low-skill play with a Rogue or Warrior, but it's fun and not just for the nostalgia.
Also and amusingly, duping is fixed on modern machines. I guess just since the clock cycles are so fast? At any rate I've tried to dupe elixirs or books, and it's impossible, just doing it with the walk and click timing. I used to have the timing down and could easily dupe 100 elixirs to boost the power curve and save endless Witch visits, but I haven't been able to dupe any books or elixirs now.