The article complains about the keyboard layout. And they are probably right.

But if you are going to use a VT-100 keyboard you might as well try an editor actually designed for that keyboard, which I remember really loving at the time. KED:

https://avitech.com.au/?page_id=959

Also, if you want efficient and fast displays on that screen, remember to use scrolling regions. They scroll the sections of the screen in hardware. By using them correctly you can insert and delete single lines without repainting the screen.