Could someone please disassemble this and finally tell us why DOS strings end with '$'? In my copy of "Accidental Empires", one of the Robert X. Cringelys has

Could someone please disassemble this and finally tell us why DOS strings end with '$'? In my copy of "Accidental Empires", one of the Robert X. Cringelys has Gary Kildall say that not even Bill Gates knows why this is true.