#96: the sim TIME MODEL closed from bytes -- myomer kinetic term restored to the faithful 28 Hz

The open question under every heat bracket was what the 1995 sim does with
time. Answered at the byte level:

* FUN_0041c018 IS the arcade Simulation::PerformAndWatch: slice =
  (till.ticks - last.ticks) / DAT_0052140c, stored, Perform(slice) --
  VARIABLE-STEP in real SECONDS, line-for-line the WinTesla SIMULATE.cpp
  body. Every dt-carrying reconstruction is unit-faithful; no tick/second
  gap exists anywhere.
* The myomer heat term's ONE caller is the unexported MyomersSimulation
  body @0x4b8b9a (E8-scan + raw disasm; export gap): once per Perform, raw
  slice, gated measuredVoltage>0 only. The dt-less kinetic pulse therefore
  fires at the FRAME cadence -- 28 Hz nominal, sagging under load
  (emergent hardware, not a code constant).
* Mover velocity is u/s (dead-reckoner @0x421f7c: pos += vel x ticksD/28),
  so the v operand is unit-faithful too.

The 0.5 "loaded-rate" witness bracket is RETIRED -- it modeled the sag as
a constant, wrong in exactly the reported scenario (open-field cruising is
a light scene; the pod held ~28 there). kSeekHeatCalib = 1.0.

Measured at the faithful rate (madcat cruise benches): recommended gear
equilibrates ~1450 -- inside the authored degradation band as a SOFT 20%
output governor (heatFactor = 1 - d^2/range^2), weapons untouched at
~110-150, ZERO jams, zero bay fires from movement alone; supercharge
~1770 (deep governor -- the manual's own expert-mode warning). That is
the authored system: degradeT=1000 is governor onset, failT=2000 the
cliff, and the coolant-loop controls are the player's lever.

New leads filed in open-questions: the climb term's gravity operand
samples 0 (bridge points at a dead cell); the engine Mover's own gravity
subtraction is per-frame dt-less (port impact unread); gait-noise phantom
acceleration feeds the accel term.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

context/decomp-reference.md

@@ -319,6 +319,22 @@ From the weapon `.SUB` records + the charge-curve `.data` constants (PE-parsed a
   Loaded ("full == the gear's seek voltage" is the arcade's own discharge algebra).  Repro +
   verify: BT_SEEKTEST seek-abuse -- pre-fix deadlocks at pct=0/alarm=3; post-fix 38 rescues,
   ends Loaded/pct=1.  `[seek]` log prints the per-gear table + rescue events.
+- **THE SIM TIME MODEL — CLOSED 2026-08-02 (issue #96) [T1]:** the arcade
+  `Simulation::PerformAndWatch` is **`FUN_0041c018`** (part_002.c:5101):
+  `slice = (till.ticks − this[4].ticks) / DAT_0052140c; this[4] = till;
+  (*this[7])(this, slice)` then watchers (`FUN_0041c08c`) + WriteSimulationUpdate
+  (`FUN_0041bd98`) — **VARIABLE-STEP, slice in real SECONDS**, line-for-line the
+  WinTesla SIMULATE.cpp body. Corollaries: every Performance's `time_slice` is
+  seconds in BOTH binary and port (no hidden tick/second unit gap); a dt-LESS
+  per-frame term (myomer kinetic @4b8d18's middle term; the Mover gravity
+  `-= **(mover+0x250)` @0x421e77) fires at the FRAME cadence = the tick rate,
+  28 Hz nominal, sagging under load. Mover velocity is u/s (the replicant
+  dead-reckoner @0x421f7c does `pos += vel × ticksΔ/DAT_0052140c`). The myomer
+  heat term's ONE caller is the **unexported MyomersSimulation body
+  @0x4b8b9a-0x4b8d0d** (E8-scan + raw disasm; the export gap hid it): calls
+  @4b8d18 once per Perform, raw slice, gated `measuredVoltage > 0` only — plus
+  a −0.011/Perform repair trickle at alarm 1 and `speedEffect(+0x31c) =
+  AvailableOutput(min(measuredV, seek gear, cap)) / owner->runSpeedBase(+0x34c)`.
 - **AMMO COOK-OFF cluster DECODED 2026-07-25 (issue #46, raw disasm `scratchpad/disammo.py`) [T1]:**
   `@004bd394` AmmoBinSimulation (arm on heatAlarm FAILURE / detonate / cancel-on-Empty);
   `@004bdb94` HandleMessage(1) = crit-induced arm; the FUSE = `Now().ticks +

context/open-questions.md

@@ -694,6 +694,22 @@ register.  ⚠ The audit also flags the damage-economy item as SELF-CONTRADICTOR
   destroyed-subsystem dark-panel look.
 
 ## Locomotion / combat polish (non-gating)
+- **Myomer climb term is DEAD in the port: the gravity operand samples 0** (found in the #96
+  cruise benches, `[myoheat] g=0` every line — `BTMechMyomerMotionSample` reads
+  `GetEnvironment()->gravityConstant` and gets 0; the binary reads `**(mover+0x250)`, a POINTER
+  the Mover holds to the live gravity cell). Harmless on flat ground (|vy|≈0 anyway) but the
+  climb-work heat never accrues on slopes. Find where our Environment gravity actually lives
+  and re-point the bridge. [T2 measured]
+- **Engine Mover gravity is dt-LESS per-frame in the binary** (`@0x421e77: vy -= **(+0x250)`,
+  raw, once per Perform — same class as the myomer kinetic term). If our linked WinTesla
+  MOVER.cpp kept that form, gravity acceleration in the port scales with OUR ~59Hz frame rate
+  (≈2.1× the pod's 28) — jump arcs, falls, missile droop all stiffer than the pod. CHECK the
+  WinTesla source's gravity line; if per-frame, it needs the same 28Hz reference-rate
+  normalization the myomer kinetic term got. [T1 binary side / T4 port impact until read]
+- **Gait-noise phantom acceleration feeds the myomer accel term** (`[myoheat] a=4..33` at
+  steady cruise — our per-frame velocity re-derivation jitters; the binary read the same
+  `AccelerationLastFrame` cell off ITS OWN gait, noise level unknown). Bounded contributor
+  (~25-40% of cruise heat-in); revisit only if the 28Hz-faithful feel is contested. [T3]
 - **✅ Interior vs exterior gait CLIP SET — DONE 2026-07-13 (task #59) [T2].** The local cockpit
   mech was leaning −8° into every walk because the authentic ctor clip-set gate
   (@part_012.c:10308-10320) was a no-op (`LoadLowDetailBody`/`LoadHighDetailBody` mislabeled the

game/reconstructed/myomers.cpp

@@ -762,35 +762,36 @@ void Myomers::MyomersDriveHeat(Scalar time_slice)
 	// exists because the binary's per-tick value depends on the pod's frame
 	// rate, which our port does not run at.
 	//
-	// THE CLOCK ORIGIN, traced 2026-08-02 (was the open question here):
-	// the DOS binary keeps its engine frame rate in the global DAT_0052140c,
-	// set once at startup --
-	//     0x401ace:  mov [0x52140c], 0x41E00000   = 28.0f   (nominal)
-	//     0x401ada:  mov [0x52140c], 0x4191A6E0   = 18.2065f (BIOS-tick fallback)
-	// -- and consumed by ~90 fmul/fdiv sites across the image as THE
-	// per-frame<->per-second conversion.  The DOS main passes it straight into
-	// the ApplicationManager ctor (0x401189: push [0x52140c]).  So the pod's
-	// nominal Performance cadence was 28 Hz, byte-proven.  [T1]
+	// THE CLOCK -- CLOSED 2026-08-02, all [T1] from bytes:
+	//   * DAT_0052140c = SystemClock ticksPerSecond, 28.0 nominal (0x401ace) /
+	//     18.2065 BIOS fallback (0x401ada).
+	//   * The arcade Simulation::PerformAndWatch is FUN_0041c018:
+	//         slice = (till.ticks - lastPerformance.ticks) / DAT_0052140c;
+	//         lastPerformance = till;  (*performance)(this, slice);
+	//     -- VARIABLE-STEP, slice in real SECONDS, line-for-line the WinTesla
+	//     SIMULATE.cpp body.  Every dt-carrying term is frame-rate independent
+	//     in BOTH the binary and the port; no unit conversion is missing.
+	//   * This term's ONE caller is the unexported MyomersSimulation body
+	//     (0x4b8b9a-0x4b8d0d, raw disasm 2026-08-02 -- the export gap hid it):
+	//     it calls 0x4b8d18 once per Perform with the RAW slice, gated only on
+	//     measuredVoltage > 0.  So the kinetic energy pulse fires once per
+	//     FRAME, and the pod's frame cadence is its tick rate: 28 Hz when
+	//     holding the deadline, sagging under load (fewer pulses/s -- an
+	//     EMERGENT hardware mercy, not a constant in the code).
 	//
-	// CALIBRATION FACTOR 0.5 -- the pod's EFFECTIVE rate under load, now
-	// corroborated from three directions (2026-08-02):
-	//   * Oracle (pod veteran), asked if the frame rate was rock solid:
-	//     "I think I could do as well with a flipbook"; heavy fights "would
-	//     turn to a slide show".
-	//   * Lynx (original-era): "RP had a target frame rate of 30FPS.  It
-	//     wasn't hard coded or locked.  BT never had a locked frame rate in
-	//     1st release testing... coming from 3.0, where 20FPS was a miracle."
-	//   * The engine's own pacer DESIGN: end_of_frame = Now() + frameDuration
-	//     with background fill and NO overrun catch-up (APPMGR.cpp, T0) --
-	//     "target 28 but allowed to slip" is the construction, and the
-	//     18.2065 BIOS fallback anticipated degraded timing.
-	// Corollary: a choking 486 generated LESS heat/s exactly during the
-	// biggest fights -- veteran memory of seek-4 endurance encodes the LOADED
-	// rate, so bracketing by their consensus is the correct instrument.
-	// Effective default 28 * 0.5 = 14 Hz [T2 multi-witness]; BT_MYO_HZ=<hz>
-	// overrides absolutely for bracketing.
+	// The faithful reference is therefore the binary's own nominal cadence,
+	// 28 Hz, full stop.  The old 0.5 "loaded-rate" calibration [T3 witness
+	// bracket] is RETIRED: it modeled the sag as a constant, which is wrong in
+	// exactly the reported scenario (open-field cruising is a LIGHT scene --
+	// the pod held ~28 there).  Measured at 28 Hz (cruise benches 2026-08-02):
+	// recommended gear equilibrates ~1450 (soft 20% output governor inside the
+	// authored degradation band, weapons unaffected, zero jams); supercharge
+	// ~1770 (deep governor, the manual's own warning).  That IS the authored
+	// system: degradeT=1000 is a governor onset, failT=2000 the cliff, and the
+	// pod's coolant-loop controls (flush/balance, Myomers on loop 5) are the
+	// player's lever.  BT_MYO_HZ=<hz> remains as the bracketing override.
 	static const Scalar kPodFrameHz    = 28.0f;	// byte-proven nominal [T1]
-	static const Scalar kSeekHeatCalib = 0.5f;	// Oracle bracket 2026-08-02 [T3]
+	static const Scalar kSeekHeatCalib = 1.0f;	// faithful (0.5 bracket retired 2026-08-02)
 	static Scalar s_hz = -1.0f;
 	if (s_hz < 0.0f)
 	{
@@ -800,7 +801,7 @@ void Myomers::MyomersDriveHeat(Scalar time_slice)
 		if (getenv("BT_MYO_LOG"))
 			DEBUG_STREAM << "[myoheat] kinetic-term reference rate: " << s_hz
 				<< " Hz (pod nominal 28 [T1] x calib " << kSeekHeatCalib
-				<< " [T3]" << (hv ? ", ENV OVERRIDE" : "") << ")" << std::endl;
+				<< (hv ? ", ENV OVERRIDE" : "") << ")" << std::endl;
 	}
 
 	Scalar termClimb   = velComplement  * vy * mass * gravity * time_slice;