SoftWindows sort of worked, but not well for DOS games. Even on this quad G5, DOSBox does need a lot of resources, though I can usually run 286 and 386 level software without too much difficulty.

However, the best DOS games emulator I ever used was VirtualPC 3.0. It won't run on OS X, but it runs like a bat out of hell on OS 9, and it is much better at DOS games than VPC 4+.

That won't get you far on an '040 tho.