Impurge is a scanner with a fixed-length attack which entered the Intel 88 hill in June 1993 and survived 854 challenges before being pushed off in January 1994.

;redcode
;name Impurge
;author Fredrik Ohrstrom

bomber  mov #26, counter
        add #26, comper
boom    mov bomb, <comper
counter djn boom, #26
adder   sub incr, @boom
comper  cmp 16, 0
        djn bomber, <stopper
stopper djn adder, #245
        spl 0, <-31
        mov 2, <-29
bomb    spl -1, <-31
incr    dat <-32, <-32

        end adder