gHashTag · Oct 19, 2026 · Oct 19, 2026 · Oct 19, 2026
@@ -396,6 +396,52 @@ Measured at 355d44a39: each still has 9 to 14 flat colours, and the PNGs are 4 t
   `foreign-budget` hook on master's own Rust lines (t27#10414). Merge the old branch into a
   master-based branch instead. The result still fast-forwards the old branch.
 
+## Application: idea factory, the OS particle design system (t27#10771)
+
+The owner wants one factory that unpacks any idea in any style preset, with every element made
+of particles, and runnable in the OS itself and on FPGA. Two specs do this:
+
+- **`specs/t27f/particle_ds.t27` is the design system.** A preset is a column in integer tables:
+  `BG`, `COL_A/B/C`, `RADIUS`, `GAIN`, `SPRING`, `DAMP`, `LAW`, `FORCE`, `KICK`, `CARD`. The five
+  are noir, neon, trit, paper and rain. **Add a preset by adding a column, never a branch in code.**
+- **`specs/t27f/idea_factory.t27` is the factory**, `(IDEA, PRESET) -> RGB24 frames`. It wraps
+  (at most 9 characters per line, 4 lines per scene, `|` cuts a scene), lays out in the 3x5 font,
+  assigns particles to glyph sub-slots and the card border, and closes on `CTA`.
+
+**Keep it FPGA-shaped.** Use Q8 fixed point. The per-step and per-pixel paths use only add,
+multiply, compare, table lookup (`kt` kernel ROM, `tt` tone ROM) and power-of-two division.
+Divide by a variable at most once per scene cut, never per pixel. The seals then carry
+`gen_hash_verilog`. That proves Verilog is emitted, not that it was synthesised. Say so.
+
+**Render the preset sweep on the lab:**
+
+1. For each preset, `sed` the `PRESET` constant. Also rename the module (for example
+   `idea_factory_p`), so the gen output does not overwrite the committed module's.
+2. Run `t27c gen`, then `zig build-exe -O ReleaseFast`.
+3. Run `./f 2>&1 1>fo.txt | ffmpeg -f rawvideo -pix_fmt rgb24 -s 1080x1920 -r 30 -i - ...`
+   (libx264, crf 19). The frames go to stderr. Send stdout to a file, **never to `/dev/null`**:
+   the lab replays `/dev/null` writes.
+4. Concatenate the five, scale to 720 and make a tile sheet. Fetch them as `B64:...:END` and
+   check sha256 on both ends.
+
+Measured: each preset takes 14 to 35 s for 216 frames, with 3072 particles.
+
+**Check legibility by numbers, because the Mac cannot read images.** Crop the settled frame at
+t = 2.2 s with ffmpeg and read `signalstats` YAVG for three regions: the text block, a gap row
+between lines, and the empty bottom. On a dark preset you want block > gap > bottom (rain:
+44.8 > 25.4 > 19.0). On paper the order flips (block 187 < gap 211). A flat triple means the
+particles never settled into letters.
+
+**Traps:**
+
+- **Read the `test-report` tail, not a grep.** A grep for pass and fail counts miscounts the
+  summary lines (`tests N`, `pass N`, `FAIL 0`, `vacuous passes 0 of N`).
+- **Rename loop variables by line range.** A rename that only changes the declaration leaves the
+  body pointing at the old name. Give each top-level loop in `main` its own name (`ia`, `ib`,
+  `ic`).
+- **Base the branch on master's tip before the PR.** If the base PR (R3) merged first, reset the branch onto
+  `origin/master`. Untracked new specs survive the reset.
+
 ## Check the whole corpus for import cycles (t27#10693)
 
 dependency-cruiser's `no-circular` and madge's `--circular` list every module on a cycle.

@@ -0,0 +1,37 @@
+{
+  "built_by": "t27c-bootstrap@0.5.2+355d44a39",
+  "closure": [
+    {
+      "spec": "specs/t27f/particle_ds.t27",
+      "spec_hash": "sha256:00e84a7492536bf54ac69aa0cd852dea4727477acee12538f9c4b145c3d9c8f3"
+    },
+    {
+      "spec": "specs/t27f/scene_raster.t27",
+      "spec_hash": "sha256:7be7118d865aa65fd1ccb989ab160df2feb46c9ded0a15ca6510b747301ee4a6"
+    }
+  ],
+  "config": "gen=c,rust,verilog,zig;tests=zig",
+  "gen_hash_c": "sha256:49e275c87108c8621d521226b89afb5f6c6a39f74de8e8bba502fbd1e39ad843",
+  "gen_hash_rust": "sha256:7d03e6e99a15344a1c8272b7f96ffc8ddcbfdb1cf44ab7f70f7a0e37847529bc",
+  "gen_hash_verilog": "sha256:0f761cb6e48d10ac555e51b8e5722eb8b02074a87ca2055aaec9241754140c49",
+  "gen_hash_zig": "sha256:0730d911d7047dc707075d16c8ff04afe222f4422a24344eff10b90e72edfdf0",
+  "module": "idea_factory",
+  "ring": 12,
+  "seal_schema": 2,
+  "sealed_at": "2026-10-19T02:25:39Z",
+  "sealed_by": "t27c-bootstrap@0.5.2",
+  "spec_hash": "sha256:34f59b06d780be9cbbae1b0577e7c96ed5b6b7d2451e61ada1b1dde2fd58b6b8",
+  "spec_path": "specs/t27f/idea_factory.t27",
+  "tests": {
+    "failed": 0,
+    "failing": [],
+    "forced": false,
+    "passed": 8,
+    "total": 8,
+    "vacuous": 0
+  },
+  "toolchain": {
+    "test_runner": "sha256:8512b80da533b79289110fca4a65f3336abd7a059ca4b72ea595d5e33ff8ad10",
+    "zig": "0.16.0"
+  }
+}
@@ -0,0 +1,33 @@
+{
+  "built_by": "t27c-bootstrap@0.5.2+355d44a39",
+  "closure": [
+    {
+      "spec": "specs/t27f/scene_raster.t27",
+      "spec_hash": "sha256:7be7118d865aa65fd1ccb989ab160df2feb46c9ded0a15ca6510b747301ee4a6"
+    }
+  ],
+  "config": "gen=c,rust,verilog,zig;tests=zig",
+  "gen_hash_c": "sha256:03823e75050d119fede755d7e3b218cd924f47ad3d310bcc39f5a00ea315a715",
+  "gen_hash_rust": "sha256:33f633fdef8835e3d69e6e758e6bb180de9e103fca81005405999c391bec82f4",
+  "gen_hash_verilog": "sha256:c5ef23af6415734e2f11a6dd645de11cd86a4f040c331595fa3f11c4765a71db",
+  "gen_hash_zig": "sha256:262eb3241c84d2de64e67b59ea700299f8cf513d1d3a3e2ecf25279f5421f63f",
+  "module": "particle_ds",
+  "ring": 12,
+  "seal_schema": 2,
+  "sealed_at": "2026-10-19T02:25:36Z",
+  "sealed_by": "t27c-bootstrap@0.5.2",
+  "spec_hash": "sha256:00e84a7492536bf54ac69aa0cd852dea4727477acee12538f9c4b145c3d9c8f3",
+  "spec_path": "specs/t27f/particle_ds.t27",
+  "tests": {
+    "failed": 0,
+    "failing": [],
+    "forced": false,
+    "passed": 12,
+    "total": 12,
+    "vacuous": 0
+  },
+  "toolchain": {
+    "test_runner": "sha256:8512b80da533b79289110fca4a65f3336abd7a059ca4b72ea595d5e33ff8ad10",
+    "zig": "0.16.0"
+  }
+}