^{Menü: Tools → Virtual C64 keyboard → show and hide keyboard}

When clicking on the menu item show and hide keyboard a check is activated (or deactivated). If the check is activated next to the menu item the C64 keyboard is shown on your screen.

Screenshot: virtual C64 - keyboard

You use the mouse to operate the virtual C64 keyboard. If the mouse hovers above a key the key is shown with a blue frame. If you press on your left mouse button you press the key on the keyboard. As soon as you release the mousebutton the pressure on the key stops. This only affects a few keys on the C64 keyboard. The space bar for example reacts to continuous pressure with lots of space characters.
It is also possible to press more than one button at a time. You use the right mouse button for this. As soon as you right click on a button a yellow frame shows that the key is locked. You release the lock with a click of either the left or right mouse button on the locked key.