I've worked with IBM VM/360, VM/SP1 and VM/SP2. The architecture of the IBM System/360 is known as "base displacement". The base is the beginning of an addressed memory space. The displacement is the byte count higher in that space of the variable's memory location. The base is at the zero byte count displacement. Thus, I suggest instead of getting wrapped around the confusion of referring to the zero domain as the first domain started at boot, we can refer to it as the base domain; zero and base being more synonymous than zero and one (first).
GarveyPatrickD 04:51, 12 December 2011 (UTC)