Question I can't seem to call up any factory presets - where are they

A factory preset is selected every time you turn the algorithm selector knob on one of the 2 effects engines - meaning that each algorithm has 1 preset. 16 possible positions (presets) of each of the 2 algorithm selector knob amounts to 16 x 16 = 256 possible combinations, minus the one where both engines are in OFF position, and that gives you a total of 255 combi-presets. The presets you can browse and load via the UP / DOWN / LOAD buttons are user presets, and they are all empty by default.