Atom industries invented the Hall Effect Trigger for small engines back in 1962 and Husqvarna , Stihl & Victa inroduced it into some of their engines the following year.
No other engine maker would pay the 20¢ royalty per unit nor buy developement rights but just waited till the patients expired ,
Back then Australian patients ran for different times in different places ranging from 15 years locally to 30 years in third world countries.
So B & S did not intorduce their reverse engineered copy of the atom called the magnetron ignition till 1977
Atom continued to make their Briggs & Stratton ( brown ) points replacement kit till 2000 .
All of the others were dropped in 1995