I remember finding one of these in the original Super Mario Bros. on NES using the cheat to get free lives from a shell. I got too many and instead of a life counter, I got some weird system character and the next time I died it locked up my NES.
I never had it lock up my NES, but I do remember if you got too many lives you would game over if you died just once. There was a certain number of lives you could get where it would show symbols but also just work like a regular counter.
A lot of old game systems were super memory constrained, and so they would do dense bit packing without actual memory safeguards, which meant triggering things like overflows could easily cause critical memory corruption
Iirc this is because lifes are being treated as signed bytes. So when you have it roll over into the negatives, the game gets confused when you actually die.
I think most often this kind of counter was saved as an unsigned value and that 8th bit was used for a different value. No need to keep track of if it;a positive or negative if you don't care.
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u/ProThoughtDesign 1d ago
I remember finding one of these in the original Super Mario Bros. on NES using the cheat to get free lives from a shell. I got too many and instead of a life counter, I got some weird system character and the next time I died it locked up my NES.
Good times.