The "Emulator 3000" can emulate various computers and consoles.
You can exit he Emulator by pressing Alt+X.
You can load a programme for the current or another machine by pressing the F3 button.
You can save the current machine's state by pressing the F2 button.
The "Screen" window can be set full-screen by Alt+Enter. Pressing the combination again will set back the window-mode.
