Posted about this on reddit (https://www.reddit.com/r/86box/comments/1uq8jf7/was_able_to_get_openstep_nextstep_x86_up_running/) a while back, haven't tried other versions yet, but this was roughly the setup i had to run NeXTSTEP in a PC-emulator called "86box" (While following the guide as presented (https://betawiki.net/wiki/Guide:Recommended_VM_configurations/Other) on betawiki, i had some alterations to fit what current versions of 86box have...):
◊ NeXTSTEP 3.3:
- Motherboard = Socket 4 Intel Premiere/PCI ED
- Processor = Pentium Overdrive
- RAM = The maximum offered RAM as by what the choosen motherboard can provide
- Mouse = PS/2
- Network = None unfortunately due to 86box not including what NeXTSTEP 3.3 can support
- CD Drive = the default as 86box provides
◊ OpenSTEP 4.2:
- CPU = Intel Pentium Overdrive II
- RAM = The maximum offered RAM as by what the chosen motherboard can provide
- Network = [PCI] DECchip 21140 "Tulip FasterNet" (Unfortunately never was truly able to test it)
I do have the disk & machine images up on my mac and i can compress and send those over to anybody who asks.