Version 2.0 provisional2.0

New features/changed behaviour:
- if config.g is not found then config.g.bak is run instead of default.g
- added error codes to SD card access error reports
- rr_files, rr_filelist, M20 S2 and M20 S3 now provide for retrieving the list if files in chunks, using a "first" parameter in rr_files/rr_filelist or "R" parameter in M20 S2/S2, and a "next" field in the response
Bug fixes:
- In absolute extrusion mode, the first move when resuming after a pause didn't extrude
- DWC didn't give the option to load a filament when no filament was loaded

15 files changed, 206 insertions, 180 deletions

diff --git a/src/BugList.txt b/src/BugList.txt
index 41a4892b..619a7bcd 100644
--- a/src/BugList.txt
+++ b/src/BugList.txt
@@ -162,7 +162,7 @@ Fixes in RC5:
 - [done] Extra axes were ignored in G2/G3 moves
 - [done] DWC and the Duet could deadlock if the Duet ran out of output buffers
 
-Fixes post RC5:
+Fixes in RC6:
 - [done] M569 report includes chopper configuration register for smart drivers
 - [done] If getting file info timed out it didn't close the file
 - [done] DHT sensor task was running out of stack space
@@ -171,50 +171,69 @@ Fixes post RC5:
 - [done] Multiple DHT sensor support
 - [done] Support DHT sensor on Duet Maestro
 - [done] Pausing between the segments of a segmented move didn't happen even if the jerk settings were high enough
-- [done - need to test filament monitors!!!] If filament monitors were deleted or the type changed, this could result in an exception
-- [seems ok] Test Upload & print function, see https://forum.duet3d.com/topic/5394/new-firmware-2-0rc5-available/52
+- [done, ok] If filament monitors were deleted or the type changed, this could result in an exception
+- [done] Support S0/S1 for simple filament monitors
 - [done, test] When step rate limiting happens, various problems, see https://forum.duet3d.com/topic/5445/unable-to-run-128-or-256-microstepping (adjust move start time)
-- [can't reproduce] Kulitorum report that first move after a pause doesn't extrude, https://forum.duet3d.com/topic/5408/does-not-extrude-first-g1-after-a-pause/7
 - [done, test] when the SD card is removed it says 1 file was invalidated even if it was more
 - [done, ok] When SD card is removed during a print we get lots of internal error messages, and no "print abandoned" or similar message, also the heaters stay on
 - [done] Emergency stop should turn off all spindles
-- [looks like was caused by using M502] Report that filaments no longer work 
 
+- [seems ok] Test Upload & print function, see https://forum.duet3d.com/topic/5394/new-firmware-2-0rc5-available/52
+
+Fixes in release 2.0:
+- [done, test] Kulitorum report that first move after a pause doesn't extrude, https://forum.duet3d.com/topic/5408/does-not-extrude-first-g1-after-a-pause/7
+- [done] Add error codes to SD card error messages
+- [tested, documentation error] chrishamm says DHT sensors on CS pins 1-4 don't work
+- [done] add facility to return rr_filelist in chunks?
+- [done] load config.g.bak if config.g not present, not default.g
+- [done] can't load filaments because DWC doesn't give the option unless a filament is already loaded
+- look at wifi disconnect issue, https://forum.duet3d.com/topic/4341/wifi-module-keeps-disconnecting/64
+
+Planned for 2.01:
+- Bezier speed curves or other S-curve acceleration, e.g. look at https://github.com/MarlinFirmware/Marlin/pull/10373/files
+- Option to send M280 servo commands just a few times instead of continuously, for E3D and BLTouch
+- Recovery from SD card errors during a print (Dan)
+- Danny's modified SCARA kinematics (workpiece is on a plate, extruder is fixed)
+- Laser support via G1 S parameter, see https://forum.duet3d.com/topic/4702/laser-cnc-support-in-rrf-gcode-semantics/4
+- Look at pushover notification support, https://forum.duet3d.com/topic/169/notification-via-pushover-or-other-service/45
 - M3 R parameter so it can restore the spinder/laser after a pause (https://forum.duet3d.com/topic/5418/cnc-laser-m3-unpause-r-parameter)
+- M81: don't give low voltage warnings when main power has just been turned off
+- Does bltouch need a default recovery time?
+- Should bltouch use digital probe mode? Some users having problems with P25 in G31 command.
+- M584 when assigning a drive, unmap any existing assignment. Also allow an axis to be mapped to driver -1.
+- Add S4 option to G1 command, like S1 but no endstop checks (needed for CoreXY, CoreXZ)
 - CNC: look at G17/18/19, see https://forum.duet3d.com/topic/4669/ooznest-workbee-screw-driven
-- PanelDue won't connect if VIN velow minimum for stepper motors [PanelDue firmware needs to recognise status 'O']
+- M569 command to allow selection of smart/dumb driver, also allow all 12 drivers to be smart
+- M569 TOFF parameter, https://forum.duet3d.com/topic/5392/does-m906-set-rms-or-peak-current/28
+- Apostrophe in quoted filename: can we make apostrophe special in SSIDs/passwords but not filenames?
+- If wifi module gets stuck in starting or changing mode state, reset it again
+- If wifi disconnects when in client mode, keep retrying the connection
+
+Other (some of these may be in 2.01):
+- Update PanelDue firmware via Duet
+- Use Heat task to read DHT sensors?
+- Add option R4 to M915 command, to do an emergency stop (useful for Z motor)
+- GCodes corresponding to rr_move and rr_mkdir, https://forum.duet3d.com/topic/5470/firmware-2-0rc6-and-1-21-1rc6-released/13
 - Add parameter to M116 to specify acceptable temperature difference
-- Laser support, see https://forum.duet3d.com/topic/4702/laser-cnc-support-in-rrf-gcode-semantics/4
-- Pushover notification support, https://forum.duet3d.com/topic/169/notification-via-pushover-or-other-service/45
 - support M205 for setting jerk
 - support G12 clean tool?
 - Add fan PWM limit, https://forum.duet3d.com/topic/5370/m106-feature-request-limit-max-pwm-parameter/4
 - M116 extra "close enough" parameter
-- Danny's modified SCARA kinematics (workpiece is on a plate, extruder is fixed)
-- Look at Bezier speed curves or other S-curve acceleration, https://github.com/MarlinFirmware/Marlin/pull/10373/files
 - after homing, warn if outside M208 movement limits on SCARA, polar etc.
 - Unexpected heaters off/tool selection behaviour, https://www.duet3d.com/forum/thread.php?pid=43059#p43059
 - warn when using : where ; was probably meant
 - Error message if you attempt movement with VIN < minimum
 - min/max RSSI display?
-- save theta, phi in move and then in DDA?
 - report RSSI in M552?
 - When VIN power too low and stepper drivers turned off, flag axes as not homed?
-- M81: don't give low voltage warnings when main power has just been turned off
-- Return "Powered down" status when VIN power has never been seen or has gone down after sending M81
 - Auto mount main SD card when inserted
 - Workplace offsets are supposed to be persistant (check NIST), https://www.duet3d.com/forum/thread.php?pid=43755#p43755
 - At the end of a simulation, restore the original workplace coordinate selection
-- apostrophe in quoted filename
 - looks like we get a Pop underflow message when you send DWC jog commands and axes are not homed
 - Add warning message when print exceeds bounds
-- Does bltouch need a default recovery time?
-- Should bltouch use digital probe mode? Some users having problems with P25 in G31 command.
-- M584 when assigning a drive, unmap any existing assignment. Also allow an axis to be mapped to driver -1.
-- Add S4 option to G1 command, like S1 but no endstop checks (needed for CoreXY, CoreXZ)
 - When uploading while a file is being printed, don't allow the currently-printing file to be replaced
 
-- if a homing command in an SD print file is aborted due to e.g. G1 Z5 in the homing file, error message should be written to both DWC and PanelDue
+- [check] if a homing command in an SD print file is aborted due to e.g. G1 Z5 in the homing file, error message should be written to both DWC and PanelDue
 - [no fault] stall detect on Z axis
 - Files generated by Cura doesn't detect layer changes, see https://www.duet3d.com/forum/thread.php?pid=40865#p40865
 - [re-test using new DuetWiFiServer] "Failed to change mode" messages after M552 S2/S0/S1 cycle
@@ -231,7 +250,6 @@ Fixes post RC5:
 - check that we never enable the drivers before we set vsense
 
 - [don't do] Don't report the motor current for a non-existent extruder
-- SD card read error handling?
 - dual extrusion layer counting, see https://www.duet3d.com/forum/thread.php?pid=34816#p34816
 - M140/M190 with no P parameter sets all bed heater temperatures (same for M141/M191)
 - M291 to lock movement and wait for it to finish?
@@ -245,9 +263,6 @@ Fixes post RC5:
 - Send reduce power command to PanelDue when main power turned off?
 - Document multiple bed and chamber heaters
 - [mostly done] Check all classes for correct initialisation
-- sd_mmc_spi doesn't acquire/release the SPI bus. Need to change this for RTOS.
-- If wifi module gets stuck in starting state, reset it again
-- If wifi disconnects when in client mode, keep retrying the connection
 
 Bug investigations:
 - [done] step errors, https://www.duet3d.com/forum/thread.php?pid=33741#p33741
diff --git a/src/Configuration.h b/src/Configuration.h
index 3a94dfd6..13f5c9d8 100644
--- a/src/Configuration.h
+++ b/src/Configuration.h
@@ -259,7 +259,7 @@ constexpr size_t FILE_BUFFER_SIZE = 128;
 #define MENU_DIR "0:/menu/"							// Directory for menu files
 
 #define CONFIG_FILE "config.g"
-#define DEFAULT_FILE "default.g"
+#define CONFIG_BACKUP_FILE "config.g.bak"
 #define DEFAULT_LOG_FILE "eventlog.txt"
 
 #define EOF_STRING "<!-- **EoF** -->"
diff --git a/src/Duet/Webserver.cpp b/src/Duet/Webserver.cpp
index cb163698..3ec41216 100644
--- a/src/Duet/Webserver.cpp
+++ b/src/Duet/Webserver.cpp
@@ -951,19 +951,23 @@ void Webserver::HttpInterpreter::GetJsonResponse(const char* request, OutputBuff
 	else if (StringEquals(request, "filelist") && GetKeyValue("dir") != nullptr)
 	{
 		OutputBuffer::Release(response);
-		response = reprap.GetFilelistResponse(GetKeyValue("dir"));
+		const char* const firstVal = GetKeyValue("first");
+		const unsigned int startAt = (firstVal == nullptr) ? 0 : (unsigned int)SafeStrtol(firstVal);
+		response = reprap.GetFilelistResponse(GetKeyValue("dir"), startAt);		// this may return nullptr
 	}
 	else if (StringEquals(request, "files"))
 	{
+		OutputBuffer::Release(response);
 		const char* dir = GetKeyValue("dir");
 		if (dir == nullptr)
 		{
 			dir = platform->GetGCodeDir();
 		}
+		const char* const firstVal = GetKeyValue("first");
+		const unsigned int startAt = (firstVal == nullptr) ? 0 : SafeStrtol(firstVal);
 		const char* const flagDirsVal = GetKeyValue("flagDirs");
 		const bool flagDirs = flagDirsVal != nullptr && atoi(flagDirsVal) == 1;
-		OutputBuffer::Release(response);
-		response = reprap.GetFilesResponse(dir, flagDirs);
+		response = reprap.GetFilesResponse(dir, startAt, flagDirs);				// this may return nullptr
 	}
 	else if (StringEquals(request, "fileinfo"))
 	{
diff --git a/src/GCodes/GCodes.cpp b/src/GCodes/GCodes.cpp
index 44bc3075..47f7947e 100644
--- a/src/GCodes/GCodes.cpp
+++ b/src/GCodes/GCodes.cpp
@@ -2115,11 +2115,11 @@ bool GCodes::LoadExtrusionAndFeedrateFromGCode(GCodeBuffer& gb)
 		moveBuffer.coords[drive] = 0.0;
 	}
 	moveBuffer.hasExtrusion = false;
+	moveBuffer.virtualExtruderPosition = virtualExtruderPosition;	// save this before we update it
 
 	// Check if we are extruding
 	if (moveBuffer.isCoordinated && gb.Seen(extrudeLetter))
 	{
-
 		// Check that we have a tool to extrude with
 		Tool* const tool = reprap.GetCurrentTool();
 		if (tool == nullptr)
@@ -2610,7 +2610,6 @@ void GCodes::FinaliseMove(GCodeBuffer& gb)
 {
 	moveBuffer.canPauseAfter = (moveBuffer.endStopsToCheck == 0);
 	moveBuffer.filePos = (&gb == fileGCode) ? gb.GetFilePosition(fileInput->BytesCached()) : noFilePosition;
-	moveBuffer.virtualExtruderPosition = virtualExtruderPosition;
 
 	if (totalSegments > 1)
 	{
diff --git a/src/GCodes/GCodes2.cpp b/src/GCodes/GCodes2.cpp
index 7d8d78e4..af298d35 100644
--- a/src/GCodes/GCodes2.cpp
+++ b/src/GCodes/GCodes2.cpp
@@ -564,6 +564,7 @@ bool GCodes::HandleMcode(GCodeBuffer& gb, const StringRef& reply)
 		}
 		{
 			const int sparam = (gb.Seen('S')) ? gb.GetIValue() : 0;
+			const unsigned int rparam = (gb.Seen('R')) ? gb.GetUIValue() : 0;
 			String<MaxFilenameLength> dir;
 			if (gb.Seen('P'))
 			{
@@ -577,7 +578,7 @@ bool GCodes::HandleMcode(GCodeBuffer& gb, const StringRef& reply)
 			OutputBuffer *fileResponse;
 			if (sparam == 2)
 			{
-				fileResponse = reprap.GetFilesResponse(dir.c_str(), true);		// Send the file list in JSON format
+				fileResponse = reprap.GetFilesResponse(dir.c_str(), rparam, true);	// send the file list in JSON format
 				if (fileResponse == nullptr)
 				{
 					return false;
@@ -586,7 +587,7 @@ bool GCodes::HandleMcode(GCodeBuffer& gb, const StringRef& reply)
 			}
 			else if (sparam == 3)
 			{
-				fileResponse = reprap.GetFilelistResponse(dir.c_str());
+				fileResponse = reprap.GetFilelistResponse(dir.c_str(), rparam);
 				if (fileResponse == nullptr)
 				{
 					return false;
@@ -597,7 +598,7 @@ bool GCodes::HandleMcode(GCodeBuffer& gb, const StringRef& reply)
 			{
 				if (!OutputBuffer::Allocate(fileResponse))
 				{
-					return false;												// Cannot allocate an output buffer, try again later
+					return false;													// cannot allocate an output buffer, try again later
 				}
 
 				// To mimic the behaviour of the official RepRapPro firmware:
diff --git a/src/Heating/Sensors/DhtSensor.cpp b/src/Heating/Sensors/DhtSensor.cpp
index 016723af..15da14bb 100644
--- a/src/Heating/Sensors/DhtSensor.cpp
+++ b/src/Heating/Sensors/DhtSensor.cpp
@@ -39,6 +39,7 @@ DhtSensorHardwareInterface::DhtSensorHardwareInterface(Pin p_pin)
 	: sensorPin(p_pin), type(DhtSensorType::none), lastResult(TemperatureError::notInitialised),
 	  lastTemperature(BAD_ERROR_TEMPERATURE), lastHumidity(BAD_ERROR_TEMPERATURE), badTemperatureCount(0)
 {
+	IoPort::SetPinMode(sensorPin, INPUT_PULLUP);
 }
 
 TemperatureError DhtSensorHardwareInterface::GetTemperatureOrHumidity(float& t, bool wantHumidity) const
@@ -117,7 +118,7 @@ GCodeResult DhtSensorHardwareInterface::Configure(TemperatureSensor *ts, unsigne
 	return rslt;
 }
 
-// Create a hardware interface object re the specified channel if there isn't already
+// Create a hardware interface object for the specified channel if there isn't already
 DhtSensorHardwareInterface *DhtSensorHardwareInterface::Create(unsigned int relativeChannel)
 {
 	if (relativeChannel >= MaxSpiTempSensors)
@@ -170,19 +171,13 @@ void DhtSensorHardwareInterface::Interrupt()
 	if (numPulses < ARRAY_SIZE(pulses))
 	{
 		const uint16_t now = Platform::GetInterruptClocks16();
-		if (digitalRead(sensorPin))
+		if (IoPort::ReadPin(sensorPin))
 		{
 			lastPulseTime = now;
 		}
 		else if (lastPulseTime != 0)
 		{
 			pulses[numPulses++] = now - lastPulseTime;
-#if 0
-			if (numPulses == ARRAY_SIZE(pulses))
-			{
-				vTaskNotifyGiveFromISR(dhtTask->GetHandle(), nullptr);	// wake up the task
-			}
-#endif
 		}
 	}
 }
@@ -191,12 +186,8 @@ void DhtSensorHardwareInterface::TakeReading()
 {
 	if (type != DhtSensorType::none)			// if sensor has been configured
 	{
-		// Send start signal. See DHT datasheet for full signal diagram:
-		// http://www.adafruit.com/datasheets/Digital%20humidity%20and%20temperature%20sensor%20AM2302.pdf
-		pinMode(sensorPin, OUTPUT_HIGH);
-		delay(250);
-
-		digitalWrite(sensorPin, LOW);
+		// Send the start bit. This must be at least 18ms for the DHT11, 0.8ms for the DHT21, and 1ms long for the DHT22.
+		IoPort::SetPinMode(sensorPin, OUTPUT_LOW);
 		delay(20);
 
 		{
@@ -204,11 +195,11 @@ void DhtSensorHardwareInterface::TakeReading()
 
 			// End the start signal by setting data line high. the sensor will respond with the start bit in 20 to 40us.
 			// We need only force the data line high long enough to charge the line capacitance, after that the pullup resistor keeps it high.
-			digitalWrite(sensorPin, HIGH);		// this will generate an interrupt, but we will ignore it
+			IoPort::WriteDigital(sensorPin, HIGH);		// this will generate an interrupt, but we will ignore it
 			delayMicroseconds(3);
 
 			// Now start reading the data line to get the value from the DHT sensor
-			pinMode(sensorPin, INPUT_PULLUP);
+			IoPort::SetPinMode(sensorPin, INPUT_PULLUP);
 
 			// It appears that switching the pin to an output disables the interrupt, so we need to call attachInterrupt here
 			// We are likely to get an immediate interrupt at this point corresponding to the low-to-high transition. We must ignore this.
diff --git a/src/Libraries/Fatfs/ff.h b/src/Libraries/Fatfs/ff.h
index 406f9d29..7f0d91ab 100644
--- a/src/Libraries/Fatfs/ff.h
+++ b/src/Libraries/Fatfs/ff.h
@@ -178,14 +178,14 @@ typedef struct {
 
 typedef enum {
 	FR_OK = 0,				/* (0) Succeeded */
-	FR_DISK_ERR,			/* (1) A hard error occured in the low level disk I/O layer */
+	FR_DISK_ERR,			/* (1) A hard error occurred in the low level disk I/O layer */
 	FR_INT_ERR,				/* (2) Assertion failed */
 	FR_NOT_READY,			/* (3) The physical drive cannot work */
 	FR_NO_FILE,				/* (4) Could not find the file */
 	FR_NO_PATH,				/* (5) Could not find the path */
 	FR_INVALID_NAME,		/* (6) The path name format is invalid */
-	FR_DENIED,				/* (7) Acces denied due to prohibited access or directory full */
-	FR_EXIST,				/* (8) Acces denied due to prohibited access */
+	FR_DENIED,				/* (7) Access denied due to prohibited access or directory full */
+	FR_EXIST,				/* (8) Access denied due to prohibited access */
 	FR_INVALID_OBJECT,		/* (9) The file/directory object is invalid */
 	FR_WRITE_PROTECTED,		/* (10) The physical drive is write protected */
 	FR_INVALID_DRIVE,		/* (11) The logical drive number is invalid */
diff --git a/src/Networking/HttpResponder.cpp b/src/Networking/HttpResponder.cpp
index 00ee1145..b96fcac2 100644
--- a/src/Networking/HttpResponder.cpp
+++ b/src/Networking/HttpResponder.cpp
@@ -533,19 +533,23 @@ bool HttpResponder::GetJsonResponse(const char* request, OutputBuffer *&response
 	else if (StringEquals(request, "filelist") && GetKeyValue("dir") != nullptr)
 	{
 		OutputBuffer::Release(response);
-		response = reprap.GetFilelistResponse(GetKeyValue("dir"));		// this may return nullptr
+		const char* const firstVal = GetKeyValue("first");
+		const unsigned int startAt = (firstVal == nullptr) ? 0 : (unsigned int)SafeStrtol(firstVal);
+		response = reprap.GetFilelistResponse(GetKeyValue("dir"), startAt);		// this may return nullptr
 	}
 	else if (StringEquals(request, "files"))
 	{
+		OutputBuffer::Release(response);
 		const char* dir = GetKeyValue("dir");
 		if (dir == nullptr)
 		{
 			dir = GetPlatform().GetGCodeDir();
 		}
+		const char* const firstVal = GetKeyValue("first");
+		const unsigned int startAt = (firstVal == nullptr) ? 0 : SafeStrtol(firstVal);
 		const char* const flagDirsVal = GetKeyValue("flagDirs");
 		const bool flagDirs = flagDirsVal != nullptr && SafeStrtol(flagDirsVal) == 1;
-		OutputBuffer::Release(response);
-		response = reprap.GetFilesResponse(dir, flagDirs);				// this may return nullptr
+		response = reprap.GetFilesResponse(dir, startAt, flagDirs);				// this may return nullptr
 	}
 	else if (StringEquals(request, "fileinfo"))
 	{
diff --git a/src/OutputMemory.cpp b/src/OutputMemory.cpp
index d7f49728..22200a1f 100644
--- a/src/OutputMemory.cpp
+++ b/src/OutputMemory.cpp
@@ -231,13 +231,17 @@ size_t OutputBuffer::cat(StringRef &str)
 }
 
 // Encode a string in JSON format and append it to a string buffer and return the number of bytes written
-size_t OutputBuffer::EncodeString(const char *src, size_t srcLength, bool allowControlChars, bool encapsulateString)
+size_t OutputBuffer::EncodeString(const char *src, size_t srcLength, bool allowControlChars, bool encapsulateString, bool prependAsterisk)
 {
 	size_t bytesWritten = 0;
 	if (encapsulateString)
 	{
 		bytesWritten += cat('"');
 	}
+	if (prependAsterisk)
+	{
+		bytesWritten += cat('*');
+	}
 
 	if (srcLength != 0)
 	{
diff --git a/src/OutputMemory.h b/src/OutputMemory.h
index 4fcdc442..c5d31787 100644
--- a/src/OutputMemory.h
+++ b/src/OutputMemory.h
@@ -54,7 +54,7 @@ class OutputBuffer
 		size_t cat(const char *src, size_t len);
 		size_t cat(StringRef &str);
 
-		size_t EncodeString(const char *src, size_t srcLength, bool allowControlChars, bool encapsulateString = true);
+		size_t EncodeString(const char *src, size_t srcLength, bool allowControlChars, bool encapsulateString = true, bool prependAsterisk = false);
 		size_t EncodeString(const StringRef& str, bool allowControlChars, bool encapsulateString = true);
 		size_t EncodeReply(OutputBuffer *src, bool allowControlChars);
 
diff --git a/src/Platform.h b/src/Platform.h
index 5c448de2..9d040849 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -952,7 +952,7 @@ inline const char* Platform::GetConfigFile() const
 
 inline const char* Platform::GetDefaultFile() const
 {
-	return DEFAULT_FILE;
+	return CONFIG_BACKUP_FILE;
 }
 
 //*****************************************************************************************************************
diff --git a/src/RepRap.cpp b/src/RepRap.cpp
index 443aaed2..914b860a 100644
--- a/src/RepRap.cpp
+++ b/src/RepRap.cpp
@@ -1254,11 +1254,15 @@ OutputBuffer *RepRap::GetStatusResponse(uint8_t type, ResponseSource source)
 				if (tool->GetFilament() != nullptr)
 				{
 					const char *filamentName = tool->GetFilament()->GetName();
+#if 0	// DC this change broke filament loading/unloading in DWC
 					if (filamentName[0] != 0)
 					{
+#endif
 						response->catf(",\"filament\":");
 						response->EncodeString(filamentName, strlen(filamentName), false);
+#if 0	// DC see above
 					}
+#endif
 				}
 
 				// Offsets
@@ -1681,7 +1685,7 @@ OutputBuffer *RepRap::GetLegacyStatusResponse(uint8_t type, int seq)
 
 // Get the list of files in the specified directory in JSON format.
 // If flagDirs is true then we prefix each directory with a * character.
-OutputBuffer *RepRap::GetFilesResponse(const char *dir, bool flagsDirs)
+OutputBuffer *RepRap::GetFilesResponse(const char *dir, unsigned int startAt, bool flagsDirs)
 {
 	// Need something to write to...
 	OutputBuffer *response;
@@ -1692,8 +1696,9 @@ OutputBuffer *RepRap::GetFilesResponse(const char *dir, bool flagsDirs)
 
 	response->copy("{\"dir\":");
 	response->EncodeString(dir, strlen(dir), false);
-	response->cat(",\"files\":[");
+	response->catf(",\"first\":%u,\"files\":[", startAt);
 	unsigned int err;
+	unsigned int nextFile = 0;
 
 	if (!platform->GetMassStorage()->CheckDriveMounted(dir))
 	{
@@ -1707,50 +1712,138 @@ OutputBuffer *RepRap::GetFilesResponse(const char *dir, bool flagsDirs)
 	{
 		err = 0;
 		FileInfo fileInfo;
-		bool firstFile = true;
+		unsigned int filesFound = 0;
 		bool gotFile = platform->GetMassStorage()->FindFirst(dir, fileInfo);	// TODO error handling here
 
 		size_t bytesLeft = OutputBuffer::GetBytesLeft(response);	// don't write more bytes than we can
-		char filename[MaxFilenameLength];
-		filename[0] = '*';
-		const char *fname;
 
 		while (gotFile)
 		{
 			if (fileInfo.fileName[0] != '.')						// ignore Mac resource files and Linux hidden files
 			{
-				// Get the long filename if possible
-				if (flagsDirs && fileInfo.isDirectory)
-				{
-					SafeStrncpy(filename + 1, fileInfo.fileName, ARRAY_SIZE(fileInfo.fileName) - 1);
-					fname = filename;
-				}
-				else
+				if (filesFound >= startAt)
 				{
-					fname = fileInfo.fileName;
-				}
+					// Make sure we can end this response properly
+					if (bytesLeft < strlen(fileInfo.fileName) * 2 + 20)
+					{
+						// No more space available - stop here
+						platform->GetMassStorage()->AbandonFindNext();
+						nextFile = filesFound;
+						break;
+					}
 
-				// Make sure we can end this response properly
-				if (bytesLeft < strlen(fname) * 2 + 4)
-				{
-					// No more space available - stop here
-					platform->GetMassStorage()->AbandonFindNext();
-					break;
+					// Write separator and filename
+					if (filesFound > startAt)
+					{
+						bytesLeft -= response->cat(',');
+					}
+
+					bytesLeft -= response->EncodeString(fileInfo.fileName, MaxFilenameLength, false, true, flagsDirs && fileInfo.isDirectory);
 				}
+				++filesFound;
+			}
+			gotFile = platform->GetMassStorage()->FindNext(fileInfo);	// TODO error handling here
+		}
+	}
+
+	if (err != 0)
+	{
+		response->catf("],\"err\":%u}", err);
+	}
+	else
+	{
+		response->catf("],\"next\":%u,\"err\":%u}", nextFile, err);
+	}
+	return response;
+}
+
+// Get a JSON-style filelist including file types and sizes
+OutputBuffer *RepRap::GetFilelistResponse(const char *dir, unsigned int startAt)
+{
+	// Need something to write to...
+	OutputBuffer *response;
+	if (!OutputBuffer::Allocate(response))
+	{
+		return nullptr;
+	}
+
+	response->copy("{\"dir\":");
+	response->EncodeString(dir, strlen(dir), false);
+	response->catf(",\"first\":%u,\"files\":[", startAt);
+	unsigned int err;
+	unsigned int nextFile = 0;
+
+	if (!platform->GetMassStorage()->CheckDriveMounted(dir))
+	{
+		err = 1;
+	}
+	else if (!platform->GetMassStorage()->DirectoryExists(dir))
+	{
+		err = 2;
+	}
+	else
+	{
+		err = 0;
+		FileInfo fileInfo;
+		unsigned int filesFound = 0;
+		bool gotFile = platform->GetMassStorage()->FindFirst(dir, fileInfo);
+		size_t bytesLeft = OutputBuffer::GetBytesLeft(response);	// don't write more bytes than we can
 
-				// Write separator and filename
-				if (!firstFile)
+		while (gotFile)
+		{
+			if (fileInfo.fileName[0] != '.')			// ignore Mac resource files and Linux hidden files
+			{
+				if (filesFound >= startAt)
 				{
-					bytesLeft -= response->cat(',');
-				}
-				bytesLeft -= response->EncodeString(fname, MaxFilenameLength, false);
+					// Make sure we can end this response properly
+					if (bytesLeft < strlen(fileInfo.fileName) * 2 + 50)
+					{
+						// No more space available - stop here
+						platform->GetMassStorage()->AbandonFindNext();
+						nextFile = filesFound;
+						break;
+					}
+
+					// Write delimiter
+					if (filesFound != 0)
+					{
+						bytesLeft -= response->cat(',');
+					}
+
+					// Write another file entry
+					bytesLeft -= response->catf("{\"type\":\"%c\",\"name\":", fileInfo.isDirectory ? 'd' : 'f');
+					bytesLeft -= response->EncodeString(fileInfo.fileName, MaxFilenameLength, false);
+					bytesLeft -= response->catf(",\"size\":%" PRIu32, fileInfo.size);
 
-				firstFile = false;
+					const struct tm * const timeInfo = gmtime(&fileInfo.lastModified);
+					if (timeInfo->tm_year <= /*19*/80)
+					{
+						// Don't send the last modified date if it is invalid
+						bytesLeft -= response->cat('}');
+					}
+					else
+					{
+						bytesLeft -= response->catf(",\"date\":\"%04u-%02u-%02uT%02u:%02u:%02u\"}",
+								timeInfo->tm_year + 1900, timeInfo->tm_mon + 1, timeInfo->tm_mday,
+								timeInfo->tm_hour, timeInfo->tm_min, timeInfo->tm_sec);
+					}
+				}
+				++filesFound;
 			}
-			gotFile = platform->GetMassStorage()->FindNext(fileInfo);	// TODO error handling here
+			gotFile = platform->GetMassStorage()->FindNext(fileInfo);
 		}
 	}
-	response->catf("],\"err\":%u}", err);
+
+	// If there is no error, don't append "err":0 because if we do then DWC thinks there has been an error - looks like it doesn't check the value
+	if (err != 0)
+	{
+		response->catf("],\"err\":%u}", err);
+	}
+	else
+	{
+		response->catf("],\"next\":%u}", nextFile);
+	}
+
 	return response;
 }
 
@@ -1840,91 +1933,6 @@ bool RepRap::GetFileInfoResponse(const char *filename, OutputBuffer *&response,
 	return true;
 }
 
-// Get a JSON-style filelist including file types and sizes
-OutputBuffer *RepRap::GetFilelistResponse(const char *dir)
-{
-	// Need something to write to...
-	OutputBuffer *response;
-	if (!OutputBuffer::Allocate(response))
-	{
-		return nullptr;
-	}
-
-	response->copy("{\"dir\":");
-	response->EncodeString(dir, strlen(dir), false);
-	response->cat(",\"files\":[");
-	unsigned int err;
-
-	if (!platform->GetMassStorage()->CheckDriveMounted(dir))
-	{
-		err = 1;
-	}
-	else if (!platform->GetMassStorage()->DirectoryExists(dir))
-	{
-		err = 2;
-	}
-	else
-	{
-		err = 0;
-		FileInfo fileInfo;
-		bool firstFile = true;
-		bool gotFile = platform->GetMassStorage()->FindFirst(dir, fileInfo);
-		size_t bytesLeft = OutputBuffer::GetBytesLeft(response);	// don't write more bytes than we can
-
-		while (gotFile)
-		{
-			if (fileInfo.fileName[0] != '.')			// ignore Mac resource files and Linux hidden files
-			{
-				// Make sure we can end this response properly
-				if (bytesLeft < strlen(fileInfo.fileName) + 70)
-				{
-					// No more space available - stop here
-					platform->GetMassStorage()->AbandonFindNext();
-					break;
-				}
-
-				// Write delimiter
-				if (!firstFile)
-				{
-					bytesLeft -= response->cat(',');
-				}
-				firstFile = false;
-
-				// Write another file entry
-				bytesLeft -= response->catf("{\"type\":\"%c\",\"name\":", fileInfo.isDirectory ? 'd' : 'f');
-				bytesLeft -= response->EncodeString(fileInfo.fileName, MaxFilenameLength, false);
-				bytesLeft -= response->catf(",\"size\":%" PRIu32, fileInfo.size);
-
-				const struct tm * const timeInfo = gmtime(&fileInfo.lastModified);
-				if (timeInfo->tm_year <= /*19*/80)
-				{
-					// Don't send the last modified date if it is invalid
-					bytesLeft -= response->cat('}');
-				}
-				else
-				{
-					bytesLeft -= response->catf(",\"date\":\"%04u-%02u-%02uT%02u:%02u:%02u\"}",
-							timeInfo->tm_year + 1900, timeInfo->tm_mon + 1, timeInfo->tm_mday,
-							timeInfo->tm_hour, timeInfo->tm_min, timeInfo->tm_sec);
-				}
-			}
-			gotFile = platform->GetMassStorage()->FindNext(fileInfo);
-		}
-	}
-
-	// If there is no error, don't append "err":0 because if we do then DWC thinks there has been an error - looks like it doesn't check the value
-	if (err != 0)
-	{
-		response->catf("],\"err\":%u}", err);
-	}
-	else
-	{
-		response->cat("]}");
-	}
-
-	return response;
-}
-
 // Send a beep. We send it to both PanelDue and the web interface.
 void RepRap::Beep(unsigned int freq, unsigned int ms)
 {
diff --git a/src/RepRap.h b/src/RepRap.h
index 213adde3..64d2d459 100644
--- a/src/RepRap.h
+++ b/src/RepRap.h
@@ -101,8 +101,8 @@ public:
 	OutputBuffer *GetStatusResponse(uint8_t type, ResponseSource source);
 	OutputBuffer *GetConfigResponse();
 	OutputBuffer *GetLegacyStatusResponse(uint8_t type, int seq);
-	OutputBuffer *GetFilesResponse(const char* dir, bool flagsDirs);
-	OutputBuffer *GetFilelistResponse(const char* dir);
+	OutputBuffer *GetFilesResponse(const char* dir, unsigned int startAt, bool flagsDirs);
+	OutputBuffer *GetFilelistResponse(const char* dir, unsigned int startAt);
 	bool GetFileInfoResponse(const char *filename, OutputBuffer *&response, bool quitEarly);
 
 	void Beep(unsigned int freq, unsigned int ms);
diff --git a/src/Storage/FileStore.cpp b/src/Storage/FileStore.cpp
index 1a3b25e7..07322cb9 100644
--- a/src/Storage/FileStore.cpp
+++ b/src/Storage/FileStore.cpp
@@ -77,7 +77,7 @@ bool FileStore::Open(const char* directory, const char* fileName, OpenMode mode)
 				filePath[i] = 0;
 				if (!reprap.GetPlatform().GetMassStorage()->DirectoryExists(filePath.GetRef()) && !reprap.GetPlatform().GetMassStorage()->MakeDirectory(filePath.c_str()))
 				{
-					reprap.GetPlatform().MessageF(ErrorMessage, "Failed to create directory %s while trying to open file %s\n", filePath.c_str(), location.c_str());
+					reprap.GetPlatform().MessageF(ErrorMessage, "Failed to create folder %s while trying to open file %s\n", filePath.c_str(), location.c_str());
 					return false;
 				}
 				filePath[i] = '/';
@@ -102,7 +102,7 @@ bool FileStore::Open(const char* directory, const char* fileName, OpenMode mode)
 		// It is up to the caller to report an error if necessary.
 		if (reprap.Debug(modulePlatform))
 		{
-			reprap.GetPlatform().MessageF(ErrorMessage, "Can't open %s to %s, error code %d\n", location.c_str(), (writing) ? "write" : "read", openReturn);
+			reprap.GetPlatform().MessageF(ErrorMessage, "Can't open %s to %s, error code %d\n", location.c_str(), (writing) ? "write" : "read", (int)openReturn);
 		}
 		return false;
 	}
@@ -286,7 +286,7 @@ int FileStore::Read(char* extBuf, size_t nBytes)
 			FRESULT readStatus = f_read(&file, extBuf, nBytes, &bytes_read);
 			if (readStatus != FR_OK)
 			{
-				reprap.GetPlatform().Message(ErrorMessage, "Cannot read file.\n");
+				reprap.GetPlatform().MessageF(ErrorMessage, "Cannot read file, error code %d.\n", (int)readStatus);
 				return -1;
 			}
 			return (int)bytes_read;
@@ -397,7 +397,7 @@ bool FileStore::Write(const char *s, size_t len)
 
 			if ((writeStatus != FR_OK) || (totalBytesWritten != len))
 			{
-				reprap.GetPlatform().Message(ErrorMessage, "Failed to write to file. Drive may be full.\n");
+				reprap.GetPlatform().MessageF(ErrorMessage, "Failed to write to file, error code %d. Card may be full.\n", (int)writeStatus);
 				return false;
 			}
 			return true;
@@ -432,7 +432,7 @@ bool FileStore::Flush()
 
 				if ((writeStatus != FR_OK) || (bytesToWrite != bytesWritten))
 				{
-					reprap.GetPlatform().Message(ErrorMessage, "Failed to write to file. Drive may be full.\n");
+					reprap.GetPlatform().MessageF(ErrorMessage, "Failed to flush data to file, error code %d. Card may be full.\n", (int)writeStatus);
 					return false;
 				}
 			}
diff --git a/src/Version.h b/src/Version.h
index 0a6ddc9e..6c5ebe24 100644
--- a/src/Version.h
+++ b/src/Version.h
@@ -18,11 +18,11 @@
 # define RTOSVER
 #endif
 
-# define VERSION MAIN_VERSION RTOSVER "RC6"
+# define VERSION MAIN_VERSION RTOSVER
 #endif
 
 #ifndef DATE
-# define DATE "2018-05-29b4"
+# define DATE "2018-06-05b3"
 #endif
 
 #define AUTHORS "reprappro, dc42, chrishamm, t3p3, dnewman"