Entry is via the computer keyboard.
No midi equipment is needed. It has been jazzed up since then and has been converted to QBasic. It is freely offered here for non-commercial use. There are a number of features which are not documented in the program itself but which are very useful. I've found that the hand quickly learns this pattern and you can enter a voice part of a score almost fast enough so that you can hear the music, and any errors as they happen.