# std79 DoE — 3(architecture) × 9(identity) × 3(replicate) randomized full-factorial

The formal successor to `experiments/std79-exerciser/`'s ad hoc campaign (see FABRIC-3.md §XII),
requested as a genuine randomized full-factorial design matching this project's own DoE
methodology (`capsules/doe.4th`'s Fisher-Yates run-matrix shuffle) rather than convenience
batching — and written entirely in FORTH, not host-orchestrated shell scripting. See
FABRIC-3.md §XV for the full design writeup, including a real aarch64 bug found and worked
around along the way (not root-caused — flagged there for later).

`std79-doe.fth` is not a capsule loaded via `EXEC` — feed it as raw text to a running REPL
(e.g. `socat - UNIX-CONNECT:<serial_sock> < std79-doe.fth`), same as the original exerciser, then
invoke `EXEC-STD79-DOE ( seed lo hi -- )` once loaded. `lo`/`hi` select which identity-index
range (0-8) this boot's live VMs cover — pass `0 8` if all 9 identities are simultaneously
attached in one boot (works on amd64); pass a narrower range (e.g. `0 2`, `3 5`, `6 8`) to run
the DoE across multiple smaller boots when attaching all 9 at once isn't practical (see §XV —
this is how aarch64 and riscv64 were actually run). Every boot must use the *same* seed so
`INIT-MATRIX`/`SHUFFLE-MATRIX` reproduce the identical 27-slot master permutation; only the
`lo`/`hi` filter differs, so `run_id` (always the slot's true position in the master shuffle,
0-26) stays directly comparable across boots.

`results-20260911/` holds the raw captured serial output for the full campaign — `amd64-doe-
raw.log` (all 27 trials, one boot, all 9 identities simultaneously live) and
`{aarch64,riscv64}-doe-batch{1,2,3}-raw.log` (27 trials each, split across 3 boots of 3
identities per the workaround above). **Result: 81/81 trials correct, 0 mismatches** — every
identity, every replicate, every architecture, byte-identical to a single established baseline.