did DEC (or a third party) ever produce a reference listing of DEC "parts codes" against function (e.g. RK05 = removable disk, KL11 = serial interface etc.) -- Yes, the 'edited' and 'unedited' options/modules list(s) The April 1983 edited document can be found at http://bitsavers.org/pdf/dec/modules/modulesAndOptions/ There are separate catalogs for documentation, since they changed more often with software releases.