233P3H1V0 is an unnamed c/3 orthogonal spaceship discovered by Hartmut Holzwart in April 1994. It was the first non-monotonicperiod-3 spaceship to be discovered.[1] Since then some smaller non-monotonic c/3 spaceships have been found based on the same front end.
#N 151P3H1V0
#C A non-monotonic c/3 spaceship based on 233P3H1V0
x = 33, y = 21, rule = B3/S23
9b5ob3ob5o9b$8b3o2bobobobo2b3o8b$7bo4b2obobob2o4bo7b$11bo2b2ob2o2bo11b
$6bo6bobobobo6bo6b$6b2o4bobo3bobo4b2o6b$6b2ob2o11b2ob2o6b$10bo2bo5bo2b
o10b$4b2o4bobo7bobo4b2o4b$6bo4bo9bo4bo6b2$5b2o19b2o5b$2b2o25b2o2b$2b2o
2b2obo13bob2o2b2o2b$bo4b5o11b5o4bob$7bo3bo9bo3bo7b$7b3obo9bob3o7b$b2o
4bobob2o7b2obobo4b2ob$b2ob2o4bobo7bobo4b2ob2ob$o3b2o21b2o3bo$4b2o21b2o
!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ AUTOSTART TRACKLOOP 3 0 -1/3 THUMBSIZE 2 GPS 3 ]]