I’ve just added a bit more information in the 78 series section on the Cosmotron Special. This describes the function of the button at 8 o’clock found on these models, with a link to a video showing it in action.

Here’s the video if you want a quick look:

http://s282.beta.photobucket.com/user/Sweephand/media/Cosmotron%20Page/7803Hacking.mp4.html