40 years ago, coke syrup was delivered in a cardboard box that looked like a humongous milk container. You had to open it, and then pour it into a container on the machine. There was a knob which you were supposed to adjust to make the soda stronger or weaker. As the product was dispensed from the fountain, the water and carbonation took place right at the nozzle. After tasting coca cola dispensed this way, I never wanted a can or bottle again. An interesting feature of the dispenser at the Woolworth's where I worked was that you could slightly pull the handle and it would dispense pure syrup. Pushing all the way forward on the handle dispensed carbonated water without syrup. I assume the feature was there to allow a true "jerk" when making floats. I don't recall ever seeing anyone use the handle in that way. They'd just pull it back, where it dispensed both syrup and carbonated water.
Coke also delivered product pre-mixed and gassed and ready to dispense in "corny" kegs. I never much liked those. I always felt the mix ratio was off, and the product kind of weak.
20 years ago, coke switched to "bag in a box" syrup. Their dispensers went computerized, which standardized the taste of the product. No longer could penny pinching restaurants turn the knob all the way down to make the product almost entirely water. I'm not really that happy with the mix ratio on these, either.