The Zooom Trick is an enhancement to the main loop of Blur-style scanners, which was first used in Zooom... by John Metcalf (Core Warrior 70). A Blur-style scanners works by scanning and clearing simultaneously in the same loop, with the scan directing the clear to whatever it finds.

Zooom... uses a trick which improves on the basic Blur-style scan loop by only including the clear in the loop once something has actually been found. This is achieved by having the clear attack positioned just above the scan loop as shown below:

     mov   *sBmb,    >sGat   ; out of the scan loop

sLoo:sub   #step,    #step*numb
     jmz.f sLoo,     @sLoo   ; a-field mutates

Once something has been detected by the scan loop, some part of our scanner needs to extend the loop to include the clear attack. In the example, we simply need to decrement the a-field of the jmz.f instruction:

     mov   *sBmb,    >sGat   ; included in the scan loop
sLoo:sub   #step,    #step*numb
     jmz.f sLoo-1,   @sLoo   ; a-field modified

Some examples of warriors using the Zooom Trick are: