When you boot up your board running the interpreter, you will not "See" the BASIC program source in memory.

A BASIC program running under the interpreter assumes the BASIC program is in DATA memory.

When you compile the program, your BASIC commands and statements are translated into the assembly language mnemonics that the BASIC interpreter would normally execute when it would interpret the BASIC program (your source file). The compiler assumes that your binary (or hex) file will be executed from CODE memory, like any other assembled or compiled program.

I have sold BASIC compilers to many customers that are buying it specifically because they don't want anyone to be able to read their BASIC source file.

-- Tom Bachmann