[biggiemac42]

Right, as far as I can tell the term "semilator" was coined for this task, so google won't help.

The middle of the RCT pattern where all of the action happens, reads its first bit 2^N generations B.S (before singularity, or before splat, whichever you prefer). Next bit is 2^(N-1) B.S. Next would be 2^(N-2), but this is what the semilator changes.

During the franky enormous gap between 2^(N-1) and 2^(N-2) generations B.S, extra spaceships come in at an orthogonal direction. These have two possible configurations, giving equivalent results to either of the possible bit reads. This accelerates the speed of bit reading, and means that N of millions can be emulated by a pattern with N less than 30. Much less initial distance, much less time. The addition of millions of cells of spaceships doesn't make the overall pattern smaller in an informational sense, just in the scale of time and distance between its constituent parts.