Straight vanilla install of FreeDOS on VirtualBox predictably fails right out of the ... box.
As soon as it starts it goes into an endless loop:
invalid opcode at 0fae invalid opcode at 0fae invalid opcode at 0fae ... etc
Bizarrely, adding the parameter 'raw' to whatever call is being made to memdisk is at least a fix for what I was using.
when you get to the main screen and then
Change from this:
I'm not sure what governs the thing that replaces [...] above. It was different on mine than the documentation where I found this suggested as a fix.