Issue #31: wire the EJECT button (EjectAmmo msg 0xb @004bb9b8) -- the in-mission unjam

Disasm-faithful transcription of the export-gap handler onto
ProjectileWeapon (MESSAGE_ENTRY id 0xb, the #19 pattern).  PRESS arms
the ~3s UpdateEject countdown (bin alarm -> Ejecting(3); gate 2 parks
the weapon offline mid-eject -- authentic).  HOLD to completion =
DumpAmmo jettisons the bay -> NoAmmo.  TAP (release early) cycles ONE
round out via FeedAmmo and returns the weapon to Loading -- clears a
jam at the cost of a round (and recovers a FailureHeat 7 while rounds
remain).  Binary structure kept exactly incl. the press-no-bin
fall-through into the release block.

AmmoBin: Ejecting(3)/Ejected(4) alarm levels decoded + named
SetAmmoState accessor (databinding rule).  Always-on forensics:
'[weap] EJECT tap' + '[ammo] bay DUMPED overboard (N rounds)'.

Rig-verified live (BT_EJECTTEST=1 / =hold on LRM15): taps eject one
round each and return the weapon to service (15->8 across cycles);
hold dumps all 16 -> NoAmmo.  Awaiting a human press of the actual
ENG-page button on a jammed weapon.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

context/decomp-reference.md

@@ -273,7 +273,11 @@ From the weapon `.SUB` records + the charge-curve `.data` constants (PE-parsed a
   novice + @4ad7d4 heat-model + press-only, then idx@0x320=(idx+1)%(max@0x32C+1), NO
   ResetFiringState); Emitter's faithful body existed as the orphaned "AdvanceSeekVoltage" (zero
   callers) -- both registered via MESSAGE_ENTRY (ids 9/0xb).  Verify: BT_SEEKTEST=1 +
-  BT_SEEK_LOG=1 → `[seek] <name> -> gear N` cycling.  EjectAmmo remains unwired (#31).
+  BT_SEEK_LOG=1 → `[seek] <name> -> gear N` cycling.  **EjectAmmo WIRED 2026-07-23 (issue
+  #31)**: MESSAGE_ENTRY id 0xb on `ProjectileWeapon::GetMessageHandlers` (projweap.cpp) +
+  `AmmoBin::SetAmmoState` accessor; rig-verified both paths (`BT_EJECTTEST=1` tap = one round
+  out/return to Loading, `=hold` = bay DUMPED; `[weap] EJECT tap` / `[ammo] bay DUMPED` logs).
+  Awaiting live cockpit-button verification.
   **EjectAmmo @004bb9b8 DECODED 2026-07-23 (raw disasm; the fn sits in a Ghidra export gap)
   [T1]** — old-timer testimony ("tap ejects a round, hold ejects the bay, eject clears a jam")
   matched the bytes exactly: novice guard @4ac9c8 → **PRESS** (`msg+0xc > 0`): bin alarm

game/reconstructed/ammobin.cpp

@@ -244,6 +244,9 @@ void AmmoBin::DumpAmmo()
 {
 	if (ammoAlarm.Level() != Empty)					// this+0x1A8 != 2
 	{
+		// ALWAYS log the bay dump (rare + forensic -- eject-hold / strip)
+		DEBUG_STREAM << "[ammo] " << GetName() << " bay DUMPED overboard ("
+			<< ammoCount << " rounds jettisoned)\n" << std::flush;
 		ammoCount = 0;								// this+0x180
 		ammoAlarm.SetLevel(Dumped);					// 5 (transient pulse)
 		ammoAlarm.SetLevel(Empty);					// 2

game/reconstructed/ammobin.hpp

@@ -94,13 +94,17 @@
 	// Ammo feed state machine (this->ammoAlarm @0x194, level @0x1A8 = word 0x6A)
 	//
 	//	The 6-level AlarmIndicator carries the feed cycle.  Levels confirmed from
-	//	usage; 3 and 4 are unobserved.
+	//	usage; 3/4 decoded 2026-07-23 from the EjectAmmo handler @004bb9b8 (press
+	//	raises 3 while the eject countdown runs; a tap-release blips 4 then 1
+	//	before the FeedAmmo pull cycles the round out).
 	//
 	public:
 		enum AmmoState {
 			Feeding		= 0,	// a round is in transit (feedTimer counting down)
 			Loaded		= 1,	// a round is chambered and ready to fire
 			Empty		= 2,	// no rounds remain
+			Ejecting	= 3,	// EJECT held -- countdown live (@004bb9b8 press)
+			Ejected		= 4,	// tap-release blip before the round cycles out
 			Dumped		= 5		// transient pulse raised by DumpAmmo() before Empty
 		};
 
@@ -169,6 +173,12 @@
 		int
 			GetAmmoState() const	{ return ammoAlarm.GetLevel(); }
 
+		// The EjectAmmo handler @004bb9b8 drives the feed alarm from the linked
+		// weapon (press -> Ejecting(3); tap-release -> Ejected(4) then Loaded(1)
+		// ahead of the FeedAmmo pull).  Named setter per the databinding rule.
+		void
+			SetAmmoState(int level)	{ ammoAlarm.SetLevel(level); }
+
 		// Rounds remaining (this+0x180) -- read-only, for the AMMO digits gauge and
 		// the [ammo] fire trace (named accessor per the databinding rule).
 		int

game/reconstructed/mech4.cpp

@@ -5753,6 +5753,36 @@ void
 			}
 		}
 
+		// issue #31 verify (BT_EJECTTEST): pulse the EJECT button on the first
+		// MissileLauncher (0xBD0) -- press, then release ~2s later (inside the
+		// 3s countdown => a TAP: one round out, weapon back to Loading).
+		// BT_EJECTTEST=hold releases at ~5s instead (past the countdown => the
+		// HOLD: UpdateEject completes, DumpAmmo jettisons the bay -> NoAmmo).
+		// The [weap] EJECT tap log + [ammo] counts verify the @004bb9b8 wiring.
+		const char *ejectTest = getenv("BT_EJECTTEST");
+		if (ejectTest && (Entity *)this == application->GetViewpointEntity())
+		{
+			static int s_ejectTest = 0;
+			int releaseAt = (*ejectTest == 'h') ? 300 : 120;	// 5s (hold) vs 2s (tap)
+			int phase = ++s_ejectTest % 480;					// 8s cycle @60Hz
+			if (phase == 0 || phase == releaseAt)				// press at 0, release later
+			{
+				for (int s = 1; s < GetSubsystemCount(); ++s)
+				{
+					Subsystem *sub = GetSubsystem(s);
+					if (sub != 0 && (int)sub->GetClassID() == 0xBD0)
+					{
+						ReceiverDataMessageOf<ControlsButton> msg(
+							0x0b /*ProjectileWeapon::EjectAmmoMessageID*/,
+							sizeof(ReceiverDataMessageOf<ControlsButton>),
+							(ControlsButton)(phase == 0 ? 1 : 0));
+						sub->Dispatch(&msg);
+						break;
+					}
+				}
+			}
+		}
+
 		// issue #20 verify (BT_BALTEST): alternate a MoveValve (id 4) press to
 		// the first condenser with a Mech BalanceCoolant (id 0x16) press every
 		// ~2s -- BT_VALVE_LOG shows the valve going 1->5 then BALANCE pulling

game/reconstructed/projweap.cpp

@@ -169,11 +169,21 @@ Derivation
 	);
 
 // task #6: inherit MechWeapon's handler set (see emitter.cpp note).
+// issue #31 (2026-07-23): register the ammo-weapon handler table @0x512210
+// {0xb, "EjectAmmo" -> @004bb9b8} on top of MechWeapon's ids 9/10 -- the pod's
+// EJECT button (tap = eject one round / unjam, hold = jettison the bay) was
+// silently swallowed.  (The energy-weapon branch binds 0xb to ToggleSeekVoltage
+// in ITS table instead -- see emitter.cpp.)
 Receiver::MessageHandlerSet&
 	ProjectileWeapon::GetMessageHandlers()
 {
+	static const Receiver::HandlerEntry entries[]=
+	{
+		MESSAGE_ENTRY(ProjectileWeapon, EjectAmmo)		// id 0xb  @004bb9b8
+	};
 	static Receiver::MessageHandlerSet messageHandlers(
-		MechWeapon::GetMessageHandlers());				// copy-inherit
+		ELEMENTS(entries), entries,
+		MechWeapon::GetMessageHandlers());				// copy-inherit (ids 9/10)
 	return messageHandlers;
 }
 Simulation::AttributeIndexSet	ProjectileWeapon::AttributeIndex;
@@ -495,6 +505,63 @@ void
 	}
 }
 
+//
+// @004bb9b8 -- the EJECT button (ammo-weapon handler table @0x512210, id 0xb).
+// Disasm-transcribed 2026-07-23 (the fn sits in a Ghidra export gap; issue
+// #31).  PRESS (data > 0, bin resolved): bin alarm -> Ejecting(3), reset the
+// countdown, ejectState = 0 (UpdateEject runs it; hold ~3s to completion =
+// DumpAmmo whole bay -> NoAmmo).  RELEASE with the countdown still live (a
+// TAP): bin alarm Ejected(4) -> Loaded(1), FeedAmmo cycles ONE round out;
+// bay dry -> weapon NoAmmo(7), else weapon -> Loading(3) + full recoil -- the
+// weapon RETURNS TO SERVICE (this is the in-mission UNJAM; it also recovers a
+// FailureHeat 7 while rounds remain).  Binary structure kept exactly: a press
+// with NO bin falls THROUGH to the release block (jle/je both target 4bba29).
+//
+void
+	ProjectileWeapon::EjectAmmoMessageHandler(ReceiverDataMessageOf<int> *message)
+{
+	if (MechSubsystem::IsDamaged())							// @4ac9c8 -- NOVICE lockout bridge
+		return;
+
+	AmmoBin *bin = (AmmoBin*)ammoBinLink.Resolve();			// FUN_00417ab4(this+0x43c)
+
+	if (message->dataContents > 0 && bin != 0)				// PRESS @4bb9d0/4bb9e9
+	{
+		bin->SetAmmoState(AmmoBin::Ejecting);				// SetLevel(bin+0x194, 3)
+		timeToEject		= totalTimeToEject;					// this+0x3f4 = this+0x3f0
+		percentOfEject	= 0.0f;								// this+0x3f8
+		ejectState		= 0;								// this+0x400 -- countdown live
+		return;												// jmp 4bbad9
+	}
+
+	// RELEASE (or press-no-bin fall-through) @4bba29
+	if (ejectState == 0)									// countdown still live -> a TAP
+	{
+		if (bin != 0)
+		{
+			bin->SetAmmoState(AmmoBin::Ejected);			// SetLevel(bin+0x194, 4)
+			bin->SetAmmoState(AmmoBin::Loaded);				// SetLevel(bin+0x194, 1)
+			bin->FeedAmmo();								// @4bd4f4 -- cycle one round out
+			if (bin->GetAmmoState() == AmmoBin::Empty)		// [bin+0x1a8] == 2
+				weaponAlarm.SetLevel(NoAmmoState);			// bay dry -> 7
+			else
+			{
+				weaponAlarm.SetLevel(3);					// -> Loading: BACK IN SERVICE
+				recoil = rechargeRate;						// this+0x3e8 = this+0x3dc (dial restarts)
+			}
+			DEBUG_STREAM << "[weap] " << GetName() << " EJECT tap: round out, "
+				<< bin->GetAmmoCount() << " left -> "
+				<< (bin->GetAmmoState() == AmmoBin::Empty ? "NoAmmo" : "reloading")
+				<< "\n" << std::flush;
+			timeToEject		= totalTimeToEject;
+			percentOfEject	= 0.0f;
+		}
+		else
+			weaponAlarm.SetLevel(NoAmmoState);				// @4bbabe -> 7
+	}
+	ejectState = -1;										// @4bbacf -- countdown cancelled
+}
+
 //
 // @004bbc78 -- bleed the firing charge (MechWeapon recoil @0x3E8) at a rate set
 // by the available bus voltage and the AmmoBin's remaining supply ratio.

game/reconstructed/projweap.hpp

@@ -102,7 +102,19 @@ class NotationFile;
 	public:
 		static Derivation ClassDerivations;		// parent = MechWeapon::ClassDerivations,
 												// name = "ProjectileWeapon" (DAT_00512280)
-		static Receiver::MessageHandlerSet& GetMessageHandlers();	// inherits MechWeapon's (task #6)
+		static Receiver::MessageHandlerSet& GetMessageHandlers();	// MechWeapon's + id 0xb EjectAmmo (issue #31)
+
+		enum { EjectAmmoMessageID = 0x0b };		// ammo-weapon table @0x512210
+
+		// @004bb9b8 -- the ammo-weapon handler table @0x512210 {0xb, "EjectAmmo"}.
+		// The pod's EJECT button: PRESS arms the ~3s UpdateEject countdown
+		// (hold-to-completion = DumpAmmo whole bay -> NoAmmo); TAP (release
+		// early) cycles ONE round out via FeedAmmo and, with ammo remaining,
+		// returns the weapon to Loading -- the in-mission UNJAM.  Wired
+		// 2026-07-23 (issue #31); disasm-faithful incl. the press-no-bin
+		// fall-through into the release block.
+		void
+			EjectAmmoMessageHandler(ReceiverDataMessageOf<int> *message);
 		static AttributeIndexSet AttributeIndex;
 		static SharedData DefaultData;
 

players/README.txt

@@ -45,10 +45,10 @@ CONTROLS (keyboard):
   A weapon gone quiet with ammo left has probably JAMMED (heat makes
   ballistic weapons jam -- authentic!).  Check its panel's ENG DATA page
   for the jam lamp (a cocked round with warning bolts).  The pod's fix
-  is the EJECT button: TAP to eject the jammed round (weapon reloads and
-  returns to service), HOLD ~3s to jettison the whole bay before it
-  cooks off.  (Wiring in progress -- until it lands, a respawn clears
-  jams.)  Watch the TEMP strip and pace salvos.
+  is the EJECT button on that weapon's ENG DATA page: TAP to eject the
+  jammed round (weapon reloads and returns to service), HOLD ~3s to
+  jettison the whole bay before it cooks off.  Watch the TEMP strip and
+  pace salvos.
   G (hold) + fire key .. regroup a weapon onto that trigger -- or hold a
      weapon panel's red PROGRAM button with the mouse and tap a fire key;
      the joystick diagram on the panel shows the binding live.