My father was in electronics and schematics of pirate decoders were being passed around between friends/colleagues (this was before the web!) He got the schematics and built one.

Later in the 90's, when TV cards became cheap enough I got one for my computer then there were software to decode the signal.

Interesting! Over in the UK we had https://en.wikipedia.org/wiki/VideoCrypt

https://downloads.bbc.co.uk/rd/pubs/reports/1995-11.pdf

An ancient Easter egg is revealed at the end of this interesting article. The "all free" code was `1337` or "leet" in leet!

[2020]