Apollo 11 Camera

As I understand it the Apollo 11 tv camera was installed upside down on it's
mount, and the initial picture of Neil Armstrong coming down the ladder was
upside down. They flipped it over in seconds though on the TV coverage.
This isn't strictly a spaceflight question, but I'm curious as to how they
were able to flip or rotate a TV picture in 1969. It's easy now with
digital technology. I'm not too knowledgeable about analogue TV
electronics. Can anyone explain to me how it was done? Thanks,

David