Summary
I believe this version of DOS was bundled with a computer of the same name (Hyosung).
It is basically the same as MS-DOS v3.20, but when VER is typed, the reply comes as "Hyosung MS-DOS v3.21". I'm not exactly sure what else was changed or added, if anything.
It is basically the same as MS-DOS v3.20, but when VER is typed, the reply comes as "Hyosung MS-DOS v3.21". I'm not exactly sure what else was changed or added, if anything.


