This reminds me of the good old homecomputer days, where a similar effect could be observed regularly - but back then it was completely a side effect and uninte

This reminds me of the good old homecomputer days, where a similar effect could be observed regularly - but back then it was completely a side effect and unintentional. Back in the day memory was very limited. CPU was slow too, but I'd even say memory was the main limitation. So, programs, and games in particular, used every single byte of the RAM. This of course left the crackers, who wanted to add their intros to the games, with a problem. The solution was to compress the game to make room for the intro. After decompression it would still fill the available RAM 100%, so where to put the decompressor? You'd put it and ran it in the video RAM, which wasn't needed during decompression. It would be overwritten when the game started, but then the decompressor wasn't needed anymore. The only side effect was that you literally could see the decompressor run on your screen.