Has anyone sat down and worked out interchangeability of memory parts on 16-bit core based systems. I'm thinking in terms of things like PDP-11s HP 21xx and DG Novas. I'm curious if anyone has compiled such a thing, aside from direct part number comparison -- or has guidance of non-like core stack replacement. I'm not planning on attempting to do anything of the kind just now, but it might be useful to know what's possible as supplies dwindle. --Colin