Probably not 486 - this was 1999-2000 timeframe, so some sort of Pentium thing.
It was definitely the new instructions though, so whatever Intel chip had the new features had this 1 stepping that had this bug (and it wasn’t the first version of the chip either)
It was definitely the new instructions though, so whatever Intel chip had the new features had this 1 stepping that had this bug (and it wasn’t the first version of the chip either)