>Once I return to work and get approval to open up the source code, I’ll make the repo public as well.

Guess approval wasn't given?

In that sense DOS programs run without any guard rails. Video memory is just a memory address where you can throw data in and it shows up on screen, but it also means that any kind of memory pointer issue can write over almost anything in RAM. It was trial and error to ensure everything worked and seeing as machines were not always online, there was a much smaller risk of security issues being leveraged.