Overlays and Mouse control added.

Made some changes this morning - the main ones  you can see here. When running the display now takes over about a quarter of the screen rather than just being up in the corner (still there for debug mode) & I got rid of the grid (useful for debugging but not otherwise), and the overlay is over the display.

The mouse also controls the paddle - you can still use O & P but this is much better.

I have one fix to make later - the pinball rotary timing is different for the Pinball cartridge, this manifests itself as not being able to go to the right hand last quarter, which makes playing the game difficult.

For some reason, probably the scanning of the overlay being a cm or two off the scanner surface or possibly the blurring or both, the circles aren't in quite the right position, but then this was only a quick hack up of the overlay anyway. My coding skills aren't bad, but I cannot draw at all. I think this is why I quite like coding games for these sorts of machines ; put me on a PC or Tablet and the graphics talent shines through, sort of ...

I will update everything when I've fixed the Pinball timing, which will be later today sometime hopefully.