Generally continuously, but it depends on how you scroll. If you're in `less` for example and holding the down key, you will probably see one line at a time, an

Generally continuously, but it depends on how you scroll. If you're in `less` for example and holding the down key, you will probably see one line at a time, and it should be very smooth. It's possible with high key repeat rates that you might get multiple lines on some frames.