diff --git a/Gameleap/code/CoreTech/Libraries/GameOS/VideoCard.cpp b/Gameleap/code/CoreTech/Libraries/GameOS/VideoCard.cpp
index 170e144d..11d7f523 100644
--- a/Gameleap/code/CoreTech/Libraries/GameOS/VideoCard.cpp
+++ b/Gameleap/code/CoreTech/Libraries/GameOS/VideoCard.cpp
@@ -48,6 +48,10 @@ int g_nDualHead2 = -1; // jcem
 int g_nNonDualHead = -1; // jcem
 int g_nMFD1 = -1; // mode 4: left 640x480 MFD monitor
 int g_nMFD2 = -1; // mode 4: right 640x480 MFD monitor
+// [tmon] Operator override for display-device selection, in Main/Radar/MFD1/MFD2 order.
+// -1 = leave that slot to auto-detection.  Populated by the -tmon command-line switch,
+// which is parsed in MW4Application's WinMain - that runs before FindVideoCards().
+int g_naMonitorOverride[4] = { -1, -1, -1, -1 };
 // MSL 5.03 Mechview
 int g_nMechViewType; // jcem : 0 - no mechview, 1 - on radar screen, 2 - on main screen
 
@@ -277,6 +281,19 @@ HRESULT CALLBACK EnumModesCallback2( LPDDSURFACEDESC2 lpDDSurfaceDesc, LPVOID lp
 //
 //
 // Called once at startup, enumerate and get caps of all 3D video cards
+//
+// [tmon] Apply a hard-assigned display device, but only if the operator supplied one
+// and it names a device that actually exists.  Anything else is ignored, so a stale
+// -tmon left on the command line of a machine with fewer monitors simply falls back
+// to auto-detection instead of breaking startup.
+//
+static void ApplyMonitorOverride(int slot, int* pTarget)
+{
+	int dev = g_naMonitorOverride[slot];
+	if ((dev >= 0) && (dev < (int)NumDevices))
+		*pTarget = dev;
+}
+
 //
 //
 void FindVideoCards()
@@ -382,6 +399,10 @@ void FindVideoCards()
 			}
 		}
 	}
+    // [tmon] Hard-assigned Main/Radar overrides.  Applied BEFORE the mode 4 MFD search
+    // below so that search still skips whichever devices the operator picked.
+    ApplyMonitorOverride(0, &Environment.FullScreenDevice);
+    ApplyMonitorOverride(1, &g_nNonDualHead);
     // Mode 4 (split dual 640x480): find two extra D3D devices beyond
     // FullScreenDevice and g_nNonDualHead.  These need no special resolution.
     {
@@ -396,6 +417,13 @@ void FindVideoCards()
             }
         }
     }
+    // [tmon] Hard-assigned MFD overrides (only meaningful with -tmfds 4).
+    ApplyMonitorOverride(2, &g_nMFD1);
+    ApplyMonitorOverride(3, &g_nMFD2);
+    // Log the final assignment so the operator can confirm which physical monitor each
+    // role landed on without needing a debugger.
+    SPEW(( GROUP_GAMEOS, "Display roles: devices=%d main=%d radar=%d mfd1=%d mfd2=%d span=%d",
+        (int)NumDevices, Environment.FullScreenDevice, g_nNonDualHead, g_nMFD1, g_nMFD2, g_nDualHead ));
     // jcem
 //
 // Check any known video cards have up to date drivers (Only on Windows9x)
diff --git a/Gameleap/code/mw4/Code/MW4Application/MW4Application.cpp b/Gameleap/code/mw4/Code/MW4Application/MW4Application.cpp
index 3c051e6d..01dc4d62 100644
--- a/Gameleap/code/mw4/Code/MW4Application/MW4Application.cpp
+++ b/Gameleap/code/mw4/Code/MW4Application/MW4Application.cpp
@@ -85,7 +85,10 @@ extern Time g_PlasmaClearTime;
 extern Time g_TOC_ADT;
 extern Time g_AUX_ADT;
 extern bool g_UseMSRSP;
-extern int g_nTypeOfMFDs; // 0 - no MFDs, 1 - orginal(5+1=dual & single), 2 - B&W(3 + 1=1 dual), 3 - color(3 + 1=2 dual)
+extern int g_nTypeOfMFDs; // 0 - no MFDs, 1 - orginal(5+1=dual & single), 2 - B&W(3 + 1=1 dual), 3 - color(3 + 1=2 dual), 4 - split dual 640x480
+// [tmon] Display-device override in Main/Radar/MFD1/MFD2 order; -1 = auto-detect.
+// Defined in CoreTech GameOS VideoCard.cpp and consumed by FindVideoCards().
+extern int g_naMonitorOverride[4];
 extern int g_nRIOType;
 extern DWORD g_dwRIOBaud; // [tbaud]
 extern LONG g_ThrottleDir;
@@ -1443,6 +1446,34 @@ int WINAPI WinMain( HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int n
 		if ((0 <= n) && (n <= 4)) // 0 - no MFDs, 1 - orginal(5+1=dual & single), 2 - B&W(3 + 1=1 dual), 3 - color(3 + 1=2 dual), 4 - split dual 640x480
 			g_nTypeOfMFDs = n;
 	}
+	// [tmon] Hard-assign the display devices when DirectDraw enumerates them in an
+	// unexpected order.  Syntax: -tmon <main>,<radar>,<mfd1>,<mfd2>
+	// Values are 1-based (the normal case is "-tmon 1,2,3,4"); a value of 0 leaves that
+	// slot to auto-detection, so "-tmon 2,1,0,0" only swaps main and radar.  Separators
+	// may be ',' '/' or ':'.  mfd1/mfd2 are only used by -tmfds 4.
+	token = strstr(all_lower, "-tmon ");
+	if (token)
+	{
+		const char* p = &token[6];
+		int slot = 0;
+		while (slot < 4)
+		{
+			while (*p == ' ')
+				p++;
+			if ((*p < '0') || ('9' < *p))
+				break;
+			int v = atoi(p);
+			while (('0' <= *p) && (*p <= '9'))
+				p++;
+			// 0 = leave auto-detected, otherwise convert 1-based to a 0-based device index
+			g_naMonitorOverride[slot] = (0 < v) ? (v - 1) : -1;
+			slot++;
+			if ((*p == ',') || (*p == '/') || (*p == ':'))
+				p++;
+			else
+				break;
+		}
+	}
 	token = strstr(all_lower, "-trio ");
 	if (token && token[6])
 	{