The that mysterious "M" is a obscure chip implemented in various early Sega’s consoles, largely the Sega Master System including specific add-ons. Fundamentally, it acts as a miniature sound https://armoire-de-commande-fabr197313.therainblog.com/41500610/decoding-sega-m-which-it-s-constitutes-why-might-it-s-achieve