There are two diverse build methods that can be used here.

One was the Makefile which called a DOS cross assembler to
build the target files.

The newer method installed today is batch file driven instead.

This is not ideal because time stamps aren't part of the picture,
and I may go back to that later, but for now I was focusing on
DOSBox specific Z80MU enabled native tool usage.

To build the core apps, the "coreapps.bat" file will do the job.