Add debug cmd line: '-alt-cpu-emu'

source/CmdLine.cpp

@@ -712,6 +712,10 @@ bool ProcessCmdLine(LPSTR lpCmdLine)
 		{
 			g_cmdLine.useHdcFirmwareV2 = true;
 		}
+		else if (strcmp(lpCmdLine, "-alt-cpu-emu") == 0)	// debug
+		{
+			g_cmdLine.useAltCpuEmulation = true;
+		}
 		else	// unsupported
 		{
 			LogFileOutput("Unsupported arg: %s\n", lpCmdLine);

source/CmdLine.h

@@ -91,6 +91,7 @@ struct CmdLine
 	bool noDisk2StepperDefer;	// debug
 	bool useHdcFirmwareV1;	// debug
 	bool useHdcFirmwareV2;
+	bool useAltCpuEmulation;	// debug
 	SS_CARDTYPE slotInsert[NUM_SLOTS];
 	SlotInfo slotInfo[NUM_SLOTS];
 	LPCSTR szImageName_drive[NUM_SLOTS][NUM_DRIVES];

source/Memory.cpp

@@ -275,6 +275,7 @@ static FILE * g_hMemTempFile = NULL;
 BYTE __stdcall IO_Annunciator(WORD programcounter, WORD address, BYTE write, BYTE value, ULONG nCycles);
 static void FreeMemImage(void);
 static bool g_isMemCacheValid = true;	// flag for is 'mem' valid - set in UpdatePaging() and valid for regular (not alternate) CPU emulation
+static bool g_forceAltCpuEmulation = false;	// set by cmd line
 
 //=============================================================================
 
@@ -528,6 +529,11 @@ bool IsZeroPageFloatingBus(void)
 	return memreadPageType[0x0000 >> 8] == MEM_FloatingBus;
 }
 
+void ForceAltCpuEmulation(void)
+{
+	g_forceAltCpuEmulation = true;
+}
+
 //=============================================================================
 
 static BYTE __stdcall IORead_C00x(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULONG nExecutedCycles)
@@ -1305,6 +1311,8 @@ static void UpdatePaging(BOOL initialize)
 		// . MemReset() -> ResetPaging(TRUE)
 		// . MemInitializeFromSnapshot() -> MemUpdatePaging(TRUE);
 		g_isMemCacheValid = !(IsAppleIIe(GetApple2Type()) && (GetCardMgr().QueryAux() == CT_Empty || GetCardMgr().QueryAux() == CT_80Col));
+		if (g_forceAltCpuEmulation)
+			g_isMemCacheValid = false;
 	}
 
 	modechanging = 0;

source/Memory.h

@@ -119,3 +119,4 @@ uint16_t ReadWordFromMemory(uint16_t addr);
 void WriteByteToMemory(uint16_t addr, uint8_t data);
 void CopyBytesFromMemoryPage(uint8_t* pDst, uint16_t srcAddr, size_t size);
 bool IsZeroPageFloatingBus(void);
+void ForceAltCpuEmulation(void);

source/Windows/AppleWin.cpp

@@ -918,6 +918,9 @@ static void RepeatInitialization(void)
 	if (g_cmdLine.noDisk2StepperDefer)
 		GetCardMgr().GetDisk2CardMgr().SetStepperDefer(false);
 
+	if (g_cmdLine.useAltCpuEmulation)
+		ForceAltCpuEmulation();
+
 	// Call DebugInitialize() after SetCurrentImageDir()
 	DebugInitialize();
 	LogFileOutput("Main: DebugInitialize()\n");