Not a mesh. A chord.
A slicer converts geometry into toolpaths because its tool is a point. The Replicator's tool is the entire boundary field — so its file format stores what triangles cannot: geometry, material, and interior in one object, as the set of resonances the thing rings at and the drive that addresses each one. Each chord is about a hundred bytes. Resolution is chord count. The object sharpens as more of the pattern arrives, like a progressive image.
The scan output is the build recipe is the acceptance test.
Scanning extracts the chords; building plays them back; checking compares the ring of the growing part against the same list. One alphabet serves all three, which is what makes every instant of fabrication also a measurement. The machine doesn't need a perfect physical model of itself — it needs to recognize the target ring. That is the luthier's method, tap-tuning a plate to a target tone, made exact.
The pattern is also honest by construction: every chord is tagged as measured or inferred, and coverage is kept in three explicit states rather than smoothed over. What the aperture never observed is never silently invented — and never fabricated to.
The replicator's file is the size of a video.
Describing an object atom-by-atom would take a storage building — but nobody needs the atomic microstate of a cup, any more than a JPEG needs the quantum state of a scene. The design point is megabytes to gigabytes per object, and that number is not an engineering compromise: it sits at the natural information content of the thing being made. A design at a bound is finished — it cannot be improved without new physics.
Memory, actuator, processor — one physics, three hats.
A holographic store, a holographic aperture, and a holographic compute step are the same mathematics running on three substrates. The machine keeps them as three separate cavities — because each one's job wants a different wavelength — but they share one language: chords in, chords out. That is the strongest structural reason to think the architecture is natural rather than assembled.
The chamber
Long wavelengths and real forces — engineered end-to-end as an actuator. It does the physical work, and hands every measurement to the optical layers built for information.
The store
A holographic optical medium: a cubic centimetre holds terabytes, and recall is associative — show it a partial pattern and every stored page answers at once, a bank of matched filters in parallel.
The core
A small optical cavity that settles to its answer in nanoseconds. The sense channel produces terabits per second and decisions are due in microseconds — that is not a processor workload; it is physics answering physics.
The replicator is reachable. The transporter is not.
The same arithmetic that says an object's working description is a megabyte says that capturing its exact atomic microstate would take thirteen more orders of magnitude of storage and six of time. That line is an asset: it separates the machine physics fully permits — the one we are building — from the science-fiction one it rules out, and designing hard against real bounds is exactly what makes the reachable machine inevitable rather than speculative.
At the Limit works out where every subsystem sits against the bounds physics will not move; the Field Compiler is the software that turns patterns into boundary drive — its viewport is the machine's build volume, and the emulator's API is the hardware's API.