Pendulum is a .75c scanner related to HSA which restores the scan pointer
after the attack to avoid breaking the scan pattern. There's also no
need to initialise the scan pointer. Here's the version currently on the
94x hill:

;redcode-94x
;name Pendulum X
;author John Metcalf
;strategy .75c scanner
;assert CORESIZE==55440

step equ 13
ptr equ (inc-step)

bomb spl #0, {0

wipe mov @last, <ptr
mov >ptr, >ptr
jmn.f wipe, >ptr

reset mov.ab ptr, ptr

scan sub inc, ptr
sne.x *ptr, @ptr
inc sub.x #-2*step, ptr
jmz.f scan, @ptr

slt ptr, #last+4-ptr
djn wipe, ptr
djn reset, #13
last djn.f reset, #bomb

end reset

Widely-space pointers are also possible (within limits) and can be
effective. E.g. using 4009 as the step in CORESIZE 8000 and placing the
ptr at -2*step = -18:

;redcode-94
;name Pendulum-4009
;author John Metcalf
;strategy .75c scanner
;assert CORESIZE==8000

step equ 4009
ptr equ (inc-2*step)

bomb spl #0, {0

wipe mov @last, <ptr
mov >ptr, >ptr
jmn.f wipe, >ptr

reset mov.ab ptr, ptr

scan sub.x inc, ptr
sne.x *ptr, @ptr
inc sub.f #-step, ptr
jmz.f scan, @ptr

slt ptr, #last+4-ptr
djn wipe, ptr
djn reset, #17
last djn.f reset, #bomb

end reset

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)