Button Interface (Sega Mega-Tech) Updated Mar 15, 2026 · 12 min read · 0 viewing Log in or register to read the full article. Previous Coin Meter (Sega Mega-Tech) When the Sega Mega-Tech boots up, the SMS system first disables the controller inputs on the Mega Dr... Next Port Expander IC24 (Sega Mega-Tech) The IC24 I/O Expander CXD1095 connects the SMS Z80 data pins to various places, including the YM2612...