I had one with a pulsamatic transmission.
You turned the taps on and off to fill the tub. There were two control dials.
One was a timer. The other was a four position control knob.
Off
Wash
Spin
Heat
To get the machine to heat, you would put the suds saving ball over the end of the drain hose. Fill the wash tub and then spin the water into the outer tub. You’d set the controller to Heat and the times to hold. When it was hot enough, you switch it to wash, take the suds ball off the end of the hose, and let the water back into the tub.