The original problem sounds like HIMEM.SYS or somesuch is loading...

| When you tried dosboot.com, what syntax did you use?  Did you try to
| dosboot netbsd.INSTALL.gz, or did you gzip -d first?  I couldn't
| find any documentation on dosboot, so I don't know if there is
| anything more than dosboot kernel-name using the actual kernel-name
| in place of "kernel-name", and using a DOS-compatible file name.

Where did you look? dosboot(8) is pretty complete.

--jhawk