Optimised and improved compatability for inverted split lines hardware configuration.

src/iec_bus.cpp

@@ -18,6 +18,8 @@
 
 #include "iec_bus.h"
 
+static int buttonCount = sizeof(ButtonPinFlags) / sizeof(unsigned);
+
 u32 IEC_Bus::PIGPIO_MASK_IN_ATN = 1 << PIGPIO_ATN;
 u32 IEC_Bus::PIGPIO_MASK_IN_DATA = 1 << PIGPIO_DATA;
 u32 IEC_Bus::PIGPIO_MASK_IN_CLOCK = 1 << PIGPIO_CLOCK;
@@ -58,26 +60,74 @@ u32 IEC_Bus::inputRepeatPrev[5];
 
 m6522* IEC_Bus::VIA = 0;
 
-void IEC_Bus::Read(void)
+u32 IEC_Bus::emulationModeCheckButtonIndex = 0;
+
+void IEC_Bus::ReadBrowseMode(void)
 {
 	IOPort* portB = 0;
 	unsigned gplev0 = read32(ARM_GPIO_GPLEV0);
 
 	int index;
-	int buttonCount = sizeof(ButtonPinFlags) / sizeof(unsigned);
 	for (index = 0; index < buttonCount; ++index)
 	{
 		UpdateButton(index, gplev0);
 	}
 
-	if (VIA) portB = VIA->GetPortB();
+	bool ATNIn = (gplev0 & PIGPIO_MASK_IN_ATN) == (invertIECInputs ? PIGPIO_MASK_IN_ATN : 0);
+	if (PI_Atn != ATNIn)
+	{
+		PI_Atn = ATNIn;
+	}
+
+	if (portB && (portB->GetDirection() & 0x10) == 0)
+		AtnaDataSetToOut = false; // If the ATNA PB4 gets set to an input then we can't be pulling data low. (Maniac Mansion does this)
+
+	if (!AtnaDataSetToOut && !DataSetToOut)	// only sense if we have not brought the line low (because we can't as we have the pin set to output but we can simulate in software)
+	{
+		bool DATAIn = (gplev0 & PIGPIO_MASK_IN_DATA) == (invertIECInputs ? PIGPIO_MASK_IN_DATA : 0);
+		if (PI_Data != DATAIn)
+		{
+			PI_Data = DATAIn;
+		}
+	}
+	else
+	{
+		PI_Data = true;
+	}
+
+	if (!ClockSetToOut)	// only sense if we have not brought the line low (because we can't as we have the pin set to output but we can simulate in software)
+	{
+		bool CLOCKIn = (gplev0 & PIGPIO_MASK_IN_CLOCK) == (invertIECInputs ? PIGPIO_MASK_IN_CLOCK  : 0);
+		if (PI_Clock != CLOCKIn)
+		{
+			PI_Clock = CLOCKIn;
+		}
+	}
+	else
+	{
+		PI_Clock = true;
+	}
+
+	Resetting = !ignoreReset && ((gplev0 & PIGPIO_MASK_IN_RESET) == (invertIECInputs ? PIGPIO_MASK_IN_RESET : 0));
+}
+
+void IEC_Bus::ReadEmulationMode(void)
+{
+	IOPort* portB = 0;
+	unsigned gplev0 = read32(ARM_GPIO_GPLEV0);
+
+	UpdateButton(emulationModeCheckButtonIndex, gplev0);
+	emulationModeCheckButtonIndex++;
+	emulationModeCheckButtonIndex %= buttonCount;
+
+	portB = VIA->GetPortB();
 
 	bool ATNIn = (gplev0 & PIGPIO_MASK_IN_ATN) == (invertIECInputs ? PIGPIO_MASK_IN_ATN : 0);
 	if (PI_Atn != ATNIn)
 	{
 		PI_Atn = ATNIn;
 
-		if (VIA)
+		//if (VIA)
 		{
 			if ((portB->GetDirection() & 0x10) != 0)
 			{
@@ -100,28 +150,28 @@ void IEC_Bus::Read(void)
 		if (PI_Data != DATAIn)
 		{
 			PI_Data = DATAIn;
-			if (VIA) portB->SetInput(VIAPORTPINS_DATAIN, DATAIn);	// VIA DATAin pb0 output from inverted DIN 5 DATA
+			portB->SetInput(VIAPORTPINS_DATAIN, DATAIn);	// VIA DATAin pb0 output from inverted DIN 5 DATA
 		}
 	}
 	else
 	{
 		PI_Data = true;
-		if (VIA) portB->SetInput(VIAPORTPINS_DATAIN, true);	// simulate the read in software
+		portB->SetInput(VIAPORTPINS_DATAIN, true);	// simulate the read in software
 	}
 
 	if (!ClockSetToOut)	// only sense if we have not brought the line low (because we can't as we have the pin set to output but we can simulate in software)
 	{
-		bool CLOCKIn = (gplev0 & PIGPIO_MASK_IN_CLOCK) == (invertIECInputs ? PIGPIO_MASK_IN_CLOCK  : 0);
+		bool CLOCKIn = (gplev0 & PIGPIO_MASK_IN_CLOCK) == (invertIECInputs ? PIGPIO_MASK_IN_CLOCK : 0);
 		if (PI_Clock != CLOCKIn)
 		{
 			PI_Clock = CLOCKIn;
-			if (VIA) portB->SetInput(VIAPORTPINS_CLOCKIN, CLOCKIn); // VIA CLKin pb2 output from inverted DIN 4 CLK
+			portB->SetInput(VIAPORTPINS_CLOCKIN, CLOCKIn); // VIA CLKin pb2 output from inverted DIN 4 CLK
 		}
 	}
 	else
 	{
 		PI_Clock = true;
-		if (VIA) portB->SetInput(VIAPORTPINS_CLOCKIN, true); // simulate the read in software
+		portB->SetInput(VIAPORTPINS_CLOCKIN, true); // simulate the read in software
 	}
 
 	Resetting = !ignoreReset && ((gplev0 & PIGPIO_MASK_IN_RESET) == (invertIECInputs ? PIGPIO_MASK_IN_RESET : 0));

src/iec_bus.h

@@ -328,7 +328,8 @@ public:
 		}
 	}
 
-	static void Read(void);
+	static void ReadBrowseMode(void);
+	static void ReadEmulationMode(void);
 
 	static void WaitUntilReset(void)
 	{
@@ -507,7 +508,7 @@ public:
 	{
 		while (IsAtnAsserted())
 		{
-			Read();
+			ReadBrowseMode();
 		}
 	}
 	///////////////////////////////////////////////////////////////////////////////////////////////
@@ -600,6 +601,8 @@ private:
 	static u32 PIGPIO_MASK_IN_SRQ;
 	static u32 PIGPIO_MASK_IN_RESET;
 
+	static u32 emulationModeCheckButtonIndex;
+
 	static bool PI_Atn;
 	static bool PI_Data;
 	static bool PI_Clock;

src/iec_commands.cpp

@@ -50,7 +50,7 @@ extern unsigned versionMinor;
 #define WaitWhile(checkStatus) \
 	do\
 	{\
-		IEC_Bus::Read();\
+		IEC_Bus::ReadBrowseMode();\
 		if (CheckATN()) return true;\
 	} while (checkStatus)
 
@@ -367,7 +367,7 @@ bool IEC_Commands::ReadIECSerialPort(u8& byte)
 	timer.Start(200);
 	do
 	{
-		IEC_Bus::Read();
+		IEC_Bus::ReadBrowseMode();
 		if (CheckATN()) return true;
 	}
 	while (IEC_Bus::IsClockReleased() && !timer.Tick());
@@ -396,7 +396,7 @@ void IEC_Commands::SimulateIECBegin(void)
 {
 	SetHeaderVersion();
 	Reset();
-	IEC_Bus::Read();
+	IEC_Bus::ReadBrowseMode();
 }
 
 // Paraphrasing Jim Butterfield
@@ -432,7 +432,7 @@ IEC_Commands::UpdateAction IEC_Commands::SimulateIECUpdate(void)
 		do
 		{
 			//DEBUG_LOG("Reset during SimulateIECUpdate\r\n");
-			IEC_Bus::Read();
+			IEC_Bus::ReadBrowseMode();
 			IEC_Bus::WaitMicroSeconds(100);
 		}
 		while (IEC_Bus::IsReset());
@@ -444,7 +444,7 @@ IEC_Commands::UpdateAction IEC_Commands::SimulateIECUpdate(void)
 	switch (atnSequence)
 	{
 		case ATN_SEQUENCE_IDLE:
-			IEC_Bus::Read();
+			IEC_Bus::ReadBrowseMode();
 			if (IEC_Bus::IsAtnAsserted()) atnSequence = ATN_SEQUENCE_ATN;
 			else if (selectedImageName[0] != 0) updateAction = IMAGE_SELECTED;
 		break;
@@ -462,7 +462,7 @@ IEC_Commands::UpdateAction IEC_Commands::SimulateIECUpdate(void)
 			// TODO: should set a timer here and if it times out (before the clock is released) go back to IDLE?
 			while (IEC_Bus::IsClockReleased())
 			{
-				IEC_Bus::Read();
+				IEC_Bus::ReadBrowseMode();
 			}
 		break;
 		case ATN_SEQUENCE_RECEIVE_COMMAND_CODE:

src/main.cpp

@@ -745,7 +745,7 @@ void emulator()
 
 			while (1)
 			{
-				IEC_Bus::Read();
+				IEC_Bus::ReadEmulationMode();
 
 				if (pi1541.m6502.SYNC())	// About to start a new instruction.
 				{
@@ -833,12 +833,7 @@ void emulator()
 				bool nextDisk = inputMappings->NextDisk();
 				bool prevDisk = inputMappings->PrevDisk();
 
-				if (exitEmulation)
+				if (nextDisk)
-				{
-					emulating = false;
-					break;
-				}
-				else if (nextDisk)
 				{
 					pi1541.drive.Insert(diskCaddy.PrevDisk());
 				}
@@ -864,7 +859,7 @@ void emulator()
 				}
 
 				bool reset = IEC_Bus::IsReset();
-				if (reset)
+				if (reset || exitEmulation)
 				{
 					// Clearing the caddy now
 					//	- will write back all changed/dirty/written to disk images now