▁entities ▁contributed ▁to ▁delay ▁box ▁technology ▁and ▁also ▁have ▁Intel lect ual ▁Property . ▁Some ▁of ▁these ▁other ▁entities ▁have ▁delay ▁box ▁pat ents ▁( Re id ▁and ▁Fur row ), ▁some ▁entities ▁did ▁not ▁purs ue ▁pat ents ▁for ▁their ▁invent ions ▁even ▁though ▁their ▁invent ions ▁may ▁have ▁pred ated ▁those ▁of ▁known ▁pat ent ▁hold ers . ▁ ▁In ▁the ▁late ▁ 1 9 8 0 s ▁units ▁began ▁appearing ▁in ▁the ▁market place ▁that ▁were ▁digital ▁in ▁nature ▁rendering ▁the ▁analog , ▁un ij unction , ▁R / C ▁timer ▁design ▁ob sole te . ▁ ▁The ▁new ▁digital ▁delay ▁box ▁tim ers ▁used ▁decimal ▁or ▁binary ▁c oded ▁decimal ▁thumb w heel ▁switch es ▁to ▁set ▁count down ▁timer ▁values ▁in ▁digital ▁logic . ▁ ▁The ▁thumb w he els ▁also ▁fed ▁back ▁a ▁visual ▁numerical ▁value ▁that ▁the ▁race ▁car ▁driver ▁could ▁use ▁to ▁help ▁him ▁calculate ▁proper ▁settings . ▁A ▁popular ▁early ▁digital ▁unit ▁of ▁this ▁type ▁was ▁designed ▁and ▁produced ▁by ▁Robert ▁Fur row ▁( B . ▁F . ▁Electron ics ▁of ▁We ather ford , ▁Oklahoma ). ▁ ▁Robert ▁Fur row ' s ▁delay ▁box ▁util ized ▁a ▁quart z ▁cry stal ▁for ▁timing ▁accuracy ▁and ▁Trans istor – trans istor ▁logic ▁( T TL ) ▁integrated ▁circ uits . ▁Fur row ' s ▁digital ▁delay ▁box ▁was ▁a ▁substantial ▁improvement ▁in ▁accuracy ▁and ▁erg onom ics ▁but ▁suffered ▁in ▁reli ability . ▁In ▁the ▁United ▁States ▁many ▁B . F . ▁Electron ics