DEFCOM is a msx2 game
now i remeber , in the presentation a voice says "cs127 politizen defcom"
that sentence, very clear voice!
when you enter the game, you have a computer screen with the EEUU MAP...
like the movie
as i not have any manual... i just presses every key
some one, makes the war starts, and you see the trayectory of the missiles
and you control a cursor, over the map
pressing a lot of keys,
you changes the view to a cabine of a airplain
and you can handle the controls, but you can't see the outside of the airplain
you just can open the bomb-door
and others controls like altitude....
so, ever since when i was kid, i wonders how to play. if after is more to see...

Did you manage to get the plane flying yet?
You have to select a missile on the map to 'chase'.

While flying, you have to watch which way(s) the arrows point(s).
Just note, you have to do it the other way around, i.e. if the radar points north-east, you should steer south-west.

When you have the missile's hiney in your sight, lock the target with the [SHIFT] button, then fire at it.

That's all I can remember.