Keyboard (detachable) 94 Key Support chips MC6850P ACIA "Asynchronous Common Interface Adapter" — Enables the ST to directly communicate with MIDI devices and keyboard (2 chips used). 31.25 kilobaud for MIDI, 7812.5 bit/s for keyboard. HD6301V1 "Hitachi keyboard processor" — Used for keyboard scanning and mouse/joystick ports. Keyboard (detachable) Joystick and Mouse ports (on keyboard)