Modules/input/Usage
From MSX Game Library
Check joystick bouton example:
u8 joyStat = Joystick_Read(JOY_PORT_1);
if (joyStat & JOY_INPUT_TRIGGER_A)
{
// Joystick A boutton pressed
}
else if (joyStat & JOY_INPUT_TRIGGER_B)
{
// Joystick B boutton pressed
}