▁condition . ▁ ▁Development ▁of ▁C AF S ▁started ▁in ▁I CL ' s ▁Research ▁and ▁Advanced ▁Development ▁Centre ▁under ▁Gordon ▁Sc ar rott ▁in ▁the ▁late ▁ 1 9 6 0 s ▁following ▁research ▁by ▁George ▁C oul our is ▁and ▁John ▁Evans ▁who ▁had ▁completed ▁a ▁field ▁study ▁at ▁Imperial ▁College ▁and ▁Queen ▁Mary ▁College ▁on ▁database ▁systems ▁and ▁applications ▁( S car rott , ▁ 1 9 9 5 ). ▁Their ▁study ▁had ▁revealed ▁the ▁potential ▁for ▁substantial ▁performance ▁improvements ▁in ▁large - scale ▁database ▁applications ▁by ▁the ▁inclusion ▁of ▁search ▁logic ▁in ▁the ▁disk ▁controller . ▁ ▁In ▁its ▁initial ▁form , ▁the ▁search ▁logic ▁was ▁built ▁into ▁the ▁disk ▁head . ▁A ▁stand alone ▁C AF S ▁device ▁was ▁installed ▁with ▁a ▁few ▁customers , ▁including ▁B T ▁Directory ▁En qui ries , ▁during ▁the ▁ 1 9 7 0 s . ▁The ▁device ▁was ▁subsequently ▁product ised ▁and ▁in ▁ 1 9 8 2 ▁was ▁incorpor ated ▁as ▁a ▁standard ▁feature ▁within ▁I CL ' s ▁ 2 9 0 0 ▁series ▁and ▁Series ▁ 3 9 ▁main frames . ▁By ▁this ▁stage , ▁to ▁reduce ▁costs ▁and ▁to ▁take ▁advantage ▁of ▁increased ▁hardware ▁spe eds , ▁the ▁search ▁logic ▁was ▁incorpor ated ▁into ▁the ▁disk ▁controller . ▁A ▁query ▁expressed ▁in ▁a ▁high - level ▁query ▁language ▁could ▁be ▁compiled ▁into ▁a ▁search ▁specification ▁that ▁was ▁then ▁sent ▁to ▁the ▁disk ▁controller ▁for ▁execution . ▁Initial ly ▁this ▁cap ability ▁was ▁integrated ▁into ▁I CL '