The display is detected by watching the VDP display enable bit. Controls remain disabled. However, if any credits are entered, the start button is enabled and mapped to the Fire button for the game. In this state, the controls are all randomly toggled in order to have the machine 'play' the game. The real controls are still disabled.
Credits survive restarts.
A timer counts in this mode, and if it expires, the emulator also restarts. There are two exits from this state - game over, or game win. Game Over is detected by watching the Console Music enable byte. If it is set, we next check if it's the game over tune being started. The correct address of the tune was checked by printing all music starts to debug strings.