Deflection yoke coordinate transformations

As a youngster, I once had a little fun with a TV, endowing it with the ability to display the video image upside-down, backwards, or both, by installing 2 DPDT toggle switches on the deflection yoke. This gave 4 possibilities.

Now I suppose we need to define what is meant by upside-down.

This could mean that 1 2 3 becomes 4 5 6 4 5 6 1 2 3

or it could mean that 1 2 3 becomes 6 5 4 4 5 6 3 2 1

Whichever you chose, the other would be called ``upside-down and backwards''.

Now, finally, computers can display upside-down video this fast (real-time).