> That ref was Chapter 11 of 4th edition (1952) of Radiotron Desgners > Handbook. > 1422 Pages I figured that was what it was from, after having a look at the link. > Links elsewhere t full version in one file are broken. > If anyone finds full copy in 1 file please advise url I am lucky in having a full paper copy, bought new either in the late stage= s of my apprenticeship, or just after I finished. Not sure what edition it = is, but it must have been one of the last print runs I think, because that = was the mid to late 1970s. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .