In the 80s at FORTH, Inc. we had 'shadow blocks'. Forth code would go in one block and comments in the corresponding shadow block, and you'd flip back and forth

In the 80s at FORTH, Inc. we had 'shadow blocks'. Forth code would go in one block and comments in the corresponding shadow block, and you'd flip back and forth with a keystroke. (We only had 80x25 text mode for coding, iirc. Your graphics would've been out of reach.) I don't remember how or if people kept the shadow comments lined up with code (I was only there for one summer in high school), but you could extend the editor with ease, so...