Copy protection of tape games took a different form. It wasn’t that you couldn’t make a copy, but there were extra barriers to making it playable. Eg Jet Set Willy came with a card on which was printed a coloured grid, and upon loading the game prompted you to enter the colours found at random coordinates before it would start. http://www.computinghistory.org.uk/det/57256/Jet-Set-Willy-C...

Copying that card was high effort, since no one had camera phones or scanners or photocopiers etc.