Fix for reading $C01x for Apple II and II+ models. (#1261)

source/Keyboard.cpp

@@ -333,6 +333,22 @@ static char ClipboardCurrChar(bool bIncPtr)
 	return nKey;
 }
 
+static BYTE ClipboardReadOrPeek(bool incPtr)
+{
+	if (g_bPasteFromClipboard)
+		ClipboardInit();
+
+	if (g_bClipboardActive)
+	{
+		if (*lptstr == 0)
+			ClipboardDone();
+		else
+			return 0x80 | ClipboardCurrChar(incPtr);
+	}
+
+	return 0;
+}
+
 //===========================================================================
 
 const UINT kAKDNumElements = 256/64;
@@ -402,43 +418,29 @@ BYTE KeybReadData (void)
 {
 	LogFileTimeUntilFirstKeyRead();
 
-	if (g_bPasteFromClipboard)
+	BYTE res = ClipboardReadOrPeek(false);
-		ClipboardInit();
+	if (res)
-
+		return res;
-	if (g_bClipboardActive)
-	{
-		if(*lptstr == 0)
-			ClipboardDone();
-		else
-			return 0x80 | ClipboardCurrChar(false);
-	}
-
-	//
 
 	return keycode | (keywaiting ? 0x80 : 0);
 }
 
 //===========================================================================
 
-BYTE KeybReadFlag (void)
+BYTE KeybClearStrobe(void)
 {
-	if (g_bPasteFromClipboard)
-		ClipboardInit();
-
-	if (g_bClipboardActive)
-	{
-		if(*lptstr == 0)
-			ClipboardDone();
-		else
-			return 0x80 | ClipboardCurrChar(true);
-	}
-
-	//
-
 	keywaiting = 0;
 
-	if (IS_APPLE2)	// Include Pravets machines too?
+	return ClipboardReadOrPeek(true);
-		return keycode;
+}
+
+BYTE KeybReadFlag (void)
+{
+	_ASSERT(!IS_APPLE2);	// And also not Pravets machines?
+
+	BYTE res = KeybClearStrobe();
+	if (res)
+		return res;
 
 	// AKD
 

source/Keyboard.h

@@ -17,6 +17,7 @@ void    KeybQueueKeypress(WPARAM key, Keystroke_e bASCII);
 void    KeybToggleCapsLock ();
 void    KeybToggleP8ACapsLock ();
 void    KeybAnyKeyDown(UINT message, WPARAM wparam, bool bIsExtended);
+BYTE    KeybClearStrobe(void);
 BYTE    KeybReadData (void);
 BYTE    KeybReadFlag (void);
 void    KeybSaveSnapshot(class YamlSaveHelper& yamlSaveHelper);

source/Memory.cpp

@@ -417,7 +417,10 @@ static BYTE __stdcall IOWrite_C00x(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULON
 static BYTE __stdcall IORead_C01x(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULONG nExecutedCycles)
 {
 	if (IS_APPLE2)	// Include Pravets machines too?
-		return KeybReadFlag();
+	{
+		KeybClearStrobe();
+		return IO_Null(pc, addr, bWrite, d, nExecutedCycles);	// GH#1261
+	}
 
 	bool res = false;
 	switch (addr & 0xf)
@@ -445,7 +448,7 @@ static BYTE __stdcall IORead_C01x(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULONG
 
 static BYTE __stdcall IOWrite_C01x(WORD pc, WORD addr, BYTE bWrite, BYTE d, ULONG nExecutedCycles)
 {
-	return KeybReadFlag();
+	return KeybClearStrobe();
 }
 
 //-------------------------------------