Zooom… is the clear-directing scanner which introduced the speed trick — the clear isn't started until after the scan has detected something. Zooom… entered KOTH.org's 94nop hill on 29th November 1998 and survived 441 challenges before being pushed off in December 2000. The code for Zooom… was published in Core Warrior issue 70.

;name Zooom...
;author John Metcalf
;strategy .5 scan -> .33 scan/.33 clear -> dclear
;strategy  v0.1 self modifying scan loop
;strategy   v0.2 irregular scan pattern
;strategy    v0.3 boot and tailored decoy

;assert CORESIZE==8000

     org   boot

;    [ Decoy ]
q    for   22
     for   2+(q%5==0||q%5==2||q%6==2||q%16==3)
     spl   #m*3039,  {m*3359
     spl   #0,       0       ; scanned

;    [ Boot ]
q    for   10
     mov   sGat+q-1,  >sGat
     jmp   @0,        bDis+m-sGat

bDis equ   (boot+3+923*step) ; optimal distance
step equ   1671              ; non-optimal
numb equ   2230              ; number of scans
cGat equ   (sGat-2)

;    [ Scan ]
sGat:mov   }m,       *bDis   ; multi-function
     mov   sBmb,     >sGat
sLoo:sub   #step,    #step*numb
m:   jmz.f sLoo,     @sLoo   ; a-field mutates
     mov.b sLoo,     sGat
     jmn.a {m,       *sGat

;    [ Clear ]
sBmb:spl   0,        0
cLoo:mov   cBmb,     >cGat
     djn.f cLoo,     >cGat
cBmb:dat   <2667,    2-cGat