Readout: add the Tier-1 Pixel-Planes array section (§05)

Signal-chain Pixel-Planes stage flips to "simulated"; new section shows the 64x128 tile footprint the array lit for the object (18/50), the 26-byte pixel-memory bit layout (Z24 + RGB), and states the validation + the honest remaining gap (the compiled micro-code binary, still undecoded, that carries the ground/sky). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-16 15:06:57 -05:00
parent 9d8de701f6
commit 7bd6af8c20
1 changed files with 103 additions and 7 deletions
@@ -53,6 +53,30 @@
    letter-spacing:.05em;color:var(--mute);line-height:1.5;border-top:1px solid var(--line)}
  .duo figcaption b{color:var(--phos)}

+  .arr{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:18px;align-items:start}
+  @media(max-width:640px){.arr{grid-template-columns:1fr}}
+  .arr figure{margin:0;border:1px solid var(--line2);border-radius:10px;overflow:hidden;
+    background:linear-gradient(180deg,#05090d,#070d13)}
+  .arr canvas{display:block;width:100%;height:auto}
+  .arr figcaption{padding:10px 13px;font-family:var(--mono);font-size:11px;color:var(--mute);
+    line-height:1.5;border-top:1px solid var(--line)}
+  .arr figcaption b{color:var(--phos)}
+  .arrinfo{display:flex;flex-direction:column;gap:14px;padding-top:4px}
+  .pmlab{font-family:var(--mono);font-size:10.5px;letter-spacing:.16em;text-transform:uppercase;
+    color:var(--faint)}
+  .pmbar{display:flex;gap:2px;height:34px;font-family:var(--mono);font-size:10px;font-weight:600}
+  .pmbar span{display:flex;align-items:center;justify-content:center;border-radius:3px;
+    color:#04070a;letter-spacing:.02em;white-space:nowrap;overflow:hidden}
+  .pmbar .z{flex:24;background:var(--cyan)}
+  .pmbar .r{flex:8;background:#ff6b6b}
+  .pmbar .g{flex:8;background:var(--phos)}
+  .pmbar .b{flex:8;background:#6ba8ff}
+  .pmbar .free{flex:160;background:#12202a;color:var(--faint)}
+  .mini{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:8px}
+  .mini li{position:relative;padding-left:18px;font-size:13.5px;color:var(--mute);line-height:1.45}
+  .mini li::before{content:"›";position:absolute;left:2px;color:var(--cyan);font-weight:700}
+  .mini li b{color:var(--ink)}
+
  .hero-render .tag{position:absolute;top:12px;left:16px;font-family:var(--mono);
    font-size:10.5px;letter-spacing:.18em;text-transform:uppercase;color:var(--faint);
    border:1px solid var(--line2);border-radius:5px;padding:4px 9px;z-index:2}
@@ -94,9 +118,11 @@
  .stage .d{font-size:12.5px;color:var(--mute)}
  .stage.on .v{color:var(--phos)}
  .stage.wait .v{color:var(--amber)}
+  .stage.sim .v{color:var(--cyan)}
  .stage .dot{position:absolute;top:14px;right:14px;width:7px;height:7px;border-radius:50%}
  .stage.on .dot{background:var(--phos);box-shadow:0 0 8px var(--phos)}
  .stage.wait .dot{background:var(--amber);box-shadow:0 0 8px var(--amber)}
+  .stage.sim .dot{background:var(--cyan);box-shadow:0 0 8px var(--cyan)}

  /* two-column data */
  .cols{display:grid;grid-template-columns:1.05fr .95fr;gap:20px}
@@ -195,7 +221,7 @@
      <div class="stage on"><span class="dot"></span><div class="k">cpu</div><div class="v">i860</div><div class="d">transform · clip · classify</div></div>
      <div class="stage on"><span class="dot"></span><div class="k">geom</div><div class="v">Binitize</div><div class="d">per-region 64×128 bins</div></div>
      <div class="stage on"><span class="dot"></span><div class="k">out</div><div class="v">IGC DMA</div><div class="d">SEND / TILE / FLUSH stream</div></div>
-      <div class="stage wait"><span class="dot"></span><div class="k">px</div><div class="v">Pixel-Planes</div><div class="d">bit-serial array — next build</div></div>
+      <div class="stage sim"><span class="dot"></span><div class="k">px</div><div class="v">Pixel-Planes</div><div class="d">array model simulated · §05</div></div>
    </div>
  </section>

@@ -274,7 +300,45 @@
  </section>

  <section>
-    <h2><span class="idx">05</span> What it took to get here</h2>
+    <h2><span class="idx">05</span> The Pixel-Planes array, simulated</h2>
+    <p class="sub">This is the final stage in silicon — and it now runs in software. The
+    <span class="mono">PXPL5 IGC</span> is a region rasteriser: the screen splits into
+    <b>64 × 128 tiles</b>; every pixel carries a 26-byte bit-memory and an enable bit; all
+    pixels evaluate one linear tree in lockstep —
+    <span class="mono">eval_ltree(x,y,A,B,C) = (int)(x·A + y·B + C)</span>. A triangle becomes
+    three <b>edge trees</b> into the enable register, then <b>Z and R/G/B planes</b>
+    interpolated per pixel and z-buffered in pixel memory (<span class="mono">IGCOPS.C</span>).
+    Fed the captured surface, the model lights the tiles below and renders pixels that match our
+    reference rasteriser to within edge anti-aliasing — the array reproduced faithfully.</p>
+    <div class="arr">
+      <figure>
+        <canvas id="tiles" width="500" height="360" aria-label="the object's footprint across the 64x128 tile array"></canvas>
+        <figcaption><b>the object's footprint across the array</b> — 18 of 50 tiles lit,
+        each a 64×128 region of pixel processors</figcaption>
+      </figure>
+      <div class="arrinfo">
+        <div class="pmlab">pixel memory · 26 bytes = 208 bits</div>
+        <div class="pmbar">
+          <span class="z">Z · 24b</span><span class="r">R·8</span><span class="g">G·8</span>
+          <span class="b">B·8</span><span class="free">enable + working bits</span>
+        </div>
+        <ul class="mini">
+          <li>three edge trees → the <b>enable register</b> (the inside test)</li>
+          <li>Z / R / G / B are <b>planes</b>, evaluated per pixel by the linear tree</li>
+          <li>z-buffer via <span class="mono">MEM2geMEM2</span>; every write gated by enable</li>
+          <li>output read back out of pixel memory → framebuffer</li>
+          <li><b>validated</b> pixel-faithful to the reference — ~1%, at edges only</li>
+        </ul>
+      </div>
+    </div>
+    <p class="sub" style="margin-top:16px">What this is <b>not</b>, yet: a decode of the compiled
+    <b>bit-serial micro-code</b> the DMA actually ships (§02, right). That binary encoding is still
+    undecoded, and it is how the ground and sky — which carry no stored vertices — reach the array.
+    This is the array's <b>computational</b> model: the pixels that micro-code would produce.</p>
+  </section>
+
+  <section>
+    <h2><span class="idx">06</span> What it took to get here</h2>
    <p class="sub">The i860 core was corrected against the toolchain's own assembler output
    and MAME's validated i860 model. A selection of the load-bearing fixes:</p>
    <div class="fixlist">
@@ -299,15 +363,16 @@
          <li>Real PXPL5 IGC opcode stream emitted and decoded (<b>SEND / TILE / FLUSH</b>)</li>
          <li>Geometry binned into <b>191 screen regions</b></li>
          <li>Object <b>recovered and shaded</b> — a 9×5 height-field surface, lit by the firmware's own normals (above)</li>
+          <li><b>Pixel-Planes array simulated</b> (§05) — 64×128 tiles, per-pixel memory, edge trees + z-buffer, validated pixel-faithful</li>
        </ul>
      </div>
      <div>
        <h3>The last mile to pixels</h3>
        <ul class="todo">
-          <li>Our software-shaded frame is here — the <b>board's own hardware-shaded, textured</b> frame is what remains</li>
-          <li>The SEND payloads are <b>bit-serial Pixel-Planes micro-code</b>, not stored triangles</li>
-          <li>A shaded frame needs the <b>128×64 pixel-processor array simulator</b></li>
-          <li>The model is known — <span class="mono">IGCOPS.C</span>: <span class="mono">eval_ltree = Ax+By+C</span>, an enable register, bit-serial MEM ops</li>
+          <li>The array's <b>computational model</b> runs and matches the reference — the piece left is the board's own <b>compiled micro-code</b></li>
+          <li>The DMA's SEND payloads are <b>bit-serial Pixel-Planes micro-code</b>; that binary encoding is still undecoded</li>
+          <li>It is how the <b>ground and sky</b> — which carry no stored vertices — reach the array</li>
+          <li>Cross-referencing the <span class="mono">0x0610ff / 0x00401</span> words against <span class="mono">IGCOPS.C</span> + the PXPL5 assembler is the next decode</li>
        </ul>
      </div>
    </div>
@@ -315,7 +380,7 @@

  <footer>
    <span>VWE&nbsp;TESLA REL410 · firmware-decomp · emu860</span>
-    <span>Tier 0 complete · Tier 1 (rasteriser) next</span>
+    <span>Tier 0 complete · Tier 1 array simulated · micro-code decode next</span>
  </footer>
 </div>

@@ -556,5 +621,36 @@
      bx.fillRect(px,py,CELL,CELL);
    }
  }
+
+  /* ---- IGC tile footprint: which 64x128 tiles the array lit for the object ---- */
+  var TILES={ntx:10,nty:5,touched:[[0,2],[1,1],[1,2],[2,1],[2,2],[2,3],[3,1],[3,2],[3,3],[4,1],[4,2],[4,3],[5,1],[5,2],[6,1],[6,2],[7,1],[8,1]]};
+  (function(){
+    var tc=document.getElementById('tiles'), tx=tc.getContext('2d');
+    var W=tc.width, H=tc.height, NX=TILES.ntx, NY=TILES.nty;
+    var lit={}; TILES.touched.forEach(function(t){lit[t[0]+'_'+t[1]]=1;});
+    var gap=3;
+    var cw=(H-2*gap)/(NY*2);            // enforce 64:128 -> cellH = 2*cellW
+    var ch=cw*2;
+    var gw=NX*cw, gh=NY*ch;
+    var ox=(W-gw)/2, oy=(H-gh)/2;
+    tx.clearRect(0,0,W,H);
+    for(var ty2=0;ty2<NY;ty2++)for(var tx2=0;tx2<NX;tx2++){
+      var px=ox+tx2*cw, py=oy+ty2*ch;
+      var on=lit[tx2+'_'+ty2];
+      if(on){
+        tx.fillStyle='rgba(65,255,142,0.16)'; tx.fillRect(px,py,cw-gap,ch-gap);
+        tx.strokeStyle='rgba(65,255,142,0.85)'; tx.lineWidth=1.2;
+        tx.strokeRect(px+0.5,py+0.5,cw-gap-1,ch-gap-1);
+        tx.fillStyle='rgba(65,255,142,0.9)';
+        tx.fillRect(px+cw/2-1.5,py+ch/2-1.5,3,3);
+      } else {
+        tx.strokeStyle='rgba(84,105,122,0.28)'; tx.lineWidth=1;
+        tx.strokeRect(px+0.5,py+0.5,cw-gap-1,ch-gap-1);
+      }
+    }
+    // caption-ish label of tile dimensions along the top-left cell
+    tx.fillStyle='rgba(95,208,255,0.7)'; tx.font='9px ui-monospace,monospace';
+    tx.fillText('64×128',ox+2,oy-4>8?oy-4:10);
+  })();
 })();
 </script>