Here is a very good tutorial how to install NextStep in VB:
http://stuffjasondoes.com/2018/07/25/in ... x-in-2018/
It is quite complicated, so you need to read the whole guide. It starts like this:
"Still, there are some quirks when setting up your VirtualBox VM initially. The VM must have 1 processor with 1 core, 64MB of RAM, and a 2.0GB hard disk on an IDE controller. You will need to configure one IDE CD-ROM drive and one floppy drive. The hard drive must be at IDE 0:0 (Primary Master), and the CD-ROM drive must be at IDE 0:1 (Primary Slave). You will have to edit the properties of the VM upon creation to ensure you adhere to these standards. All other default options of the VM during the creation wizard can be left alone."