<blockquote>I have to wonder how the computer tells the machine to add water in short bursts. Why does it do this?</blockquote> The cycle programming embedded into the logic chips on the board controls every aspect of the machine's operation ... just like Windows or whatever is the operating system on your computer or phone controls its operation. A water level sensor, same as on any other washer, monitors the water level in the tub. The control board adds water until the sensor registers the correct level. Filling is done in short bursts to give the tumbling load time to absorb water and get saturated and minimize the need to add more water later. If filling was done very quickly, the water level in the tub may register as full on the sensor before the load is fully saturated.