China DOS Union

device=himem.sys /testmemff
device=emm386.exe noems novcpi i=b000-b7ff

What do these parameters after these two lines mean?
Also, in a boot disk, under what circumstances is it necessary to load emm386.exe? Is it okay not to use it?

Thanks. Although I can't completely understand it, I still want to thank you for your reply.
Let me ask a more direct, or maybe even more newbie, question: if I want to load some TSR into the upper memory area, do I have to use EMM386.EXE?

As long as there is a UMB driver, that's enough. If you don't want to use a protected-mode memory manager (EMM), then use UMBPCI.