diff --git a/.gitignore b/.gitignore
index 802f897..a544753 100644
--- a/.gitignore
+++ b/.gitignore
@@ -76,3 +76,5 @@ Code/LUFA/Drivers/USB/Core/AVR8/Pipe_AVR8.o
 Code/LUFA/Drivers/USB/Core/AVR8/PipeStream_AVR8.d
 Code/LUFA/Drivers/USB/Core/AVR8/PipeStream_AVR8.o
 Code/test.rom
+EETool_pcb.jpg
+EETool_sch.jpg
diff --git a/Code/Descriptors.o b/Code/Descriptors.o
index 5de7f06..b99895f 100644
Binary files a/Code/Descriptors.o and b/Code/Descriptors.o differ
diff --git a/Code/EECommander b/Code/EECommander
index 51e32eb..9b30d8d 100755
--- a/Code/EECommander
+++ b/Code/EECommander
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 
-import sys, getopt, serial, binascii
+import sys, getopt, serial, binascii, struct
 
 
 class Mode:
@@ -20,6 +20,7 @@ class Command:
 
 PONG = 'PONG'
 BLOCKSIZE = 512
+CRCSIZE = 4
 
 romfile = ''
 serialport = ''
@@ -149,32 +150,41 @@ def dumpROM():
 
 			while 1:
 				numBytes = connection.inWaiting()
-				if numBytes>=BLOCKSIZE:
+				if numBytes>=BLOCKSIZE + CRCSIZE:
 					break
 
-			if (numBytes!=BLOCKSIZE):
+			if (numBytes!=BLOCKSIZE + CRCSIZE):
 				print 'ERROR: Block',blockNum,'failed to download. Aborting.'
 				sys.exit(2)
 
 			response = connection.read(numBytes)
+			crc = struct.unpack('<I',response[BLOCKSIZE:BLOCKSIZE+CRCSIZE])[0]
+			block = response[0:BLOCKSIZE]
+			calcCRC = binascii.crc32(block) & 0xFFFFFFFF
+			if crc != calcCRC:
+				print numBytes,'CRC failed on block',blockNum,'Read CRC =',hexU32(crc),'   Calcuated CRC =',hexU32(calcCRC)
+				print 'Aborting.'
+				sys.exit(2)
 
 			# Write the block to our file
-			destFile.write(bytes(response))
+			destFile.write(bytes(block))
 
 			sys.stdout.write('#')
 			sys.stdout.flush()
-			totalSize += numBytes
+			totalSize += numBytes - CRCSIZE
 				
 		destFile.close()
 		print '\nDone! ROM is',totalSize,'bytes.'
 		sys.exit(0)
 			
 	except (ValueError,OSError,serial.SerialException):
-
+		print 'UNKNOWN ERROR'
 		connection.close()
 		sys.exit(0)
 
 
+def hexU32(n):
+	return "0x%x"%(n&0xffffffff)
 
 def usage():
 	print '''
diff --git a/Code/EETool.c b/Code/EETool.c
index 668e82a..6cd603c 100755
--- a/Code/EETool.c
+++ b/Code/EETool.c
@@ -21,6 +21,7 @@ void Echo(const char* string);
 void WriteBlock(void);
 void ReadBlock(uint16_t startAddr, uint16_t length, bool maskROM);
 void SetAddressMSB(uint8_t addr, bool maskROM);
+uint32_t CRC32(uint8_t *buf, size_t size);
 
 
 void EVENT_USB_Device_Connect(void);
@@ -336,6 +337,14 @@ void ReadBlock(uint16_t startAddr, uint16_t length, bool maskROM)
 		
 	// Send data to host
 	CDC_Device_SendData(&EETool_CDC_Interface, gCommBuffer, length);
+	
+	// Compute a 32 bit CRC and send it
+	uint32_t crc = CRC32(gCommBuffer,length);
+	for (int i=0; i<4; i++)
+	{
+		CDC_Device_SendByte(&EETool_CDC_Interface, (uint8_t)(crc & 0xff));
+		crc>>=8;
+	}
 	_delay_ms(10);
 	
 	PULSEC(LEDPIN);
@@ -350,6 +359,28 @@ void WriteBlock()
 }
 
 
+uint32_t CRC32(uint8_t *buf, size_t size)
+{
+	// This could be made faster with a table lookup, but it's plenty fast enough for our purposes
+	int i, j;
+	uint32_t byte, crc, mask;
+	
+	i = 0;
+	crc = 0xFFFFFFFF;
+	while (size--)
+	{
+		byte = buf[i];
+		crc = crc ^ byte;
+		for (j = 7; j >= 0; j--)
+		{
+			mask = -(crc & 1);
+			crc = (crc >> 1) ^ (0xEDB88320 & mask);
+		}
+		i = i + 1;
+	}
+	return ~crc;
+}
+
 // USB Event Handlers
 void EVENT_USB_Device_Connect(void)
 {
@@ -372,5 +403,3 @@ void EVENT_USB_Device_ControlRequest(void)
 {
 	CDC_Device_ProcessControlRequest(&EETool_CDC_Interface);
 }
-
-
diff --git a/Code/EETool.xcodeproj/project.xcworkspace/xcshareddata/EETool.xccheckout b/Code/EETool.xcodeproj/project.xcworkspace/xcshareddata/EETool.xccheckout
new file mode 100644
index 0000000..a319381
--- /dev/null
+++ b/Code/EETool.xcodeproj/project.xcworkspace/xcshareddata/EETool.xccheckout
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDESourceControlProjectFavoriteDictionaryKey</key>
+	<false/>
+	<key>IDESourceControlProjectIdentifier</key>
+	<string>95794E8C-031F-41B1-9037-218BC0C75061</string>
+	<key>IDESourceControlProjectName</key>
+	<string>project</string>
+	<key>IDESourceControlProjectOriginsDictionary</key>
+	<dict>
+		<key>922DEEC8B722BFB3865485680EBE965F5270D110</key>
+		<string>https://github.com/blondie7575/EETool.git</string>
+	</dict>
+	<key>IDESourceControlProjectPath</key>
+	<string>Code/EETool.xcodeproj/project.xcworkspace</string>
+	<key>IDESourceControlProjectRelativeInstallPathDictionary</key>
+	<dict>
+		<key>922DEEC8B722BFB3865485680EBE965F5270D110</key>
+		<string>../../..</string>
+	</dict>
+	<key>IDESourceControlProjectURL</key>
+	<string>https://github.com/blondie7575/EETool.git</string>
+	<key>IDESourceControlProjectVersion</key>
+	<integer>111</integer>
+	<key>IDESourceControlProjectWCCIdentifier</key>
+	<string>922DEEC8B722BFB3865485680EBE965F5270D110</string>
+	<key>IDESourceControlProjectWCConfigurations</key>
+	<array>
+		<dict>
+			<key>IDESourceControlRepositoryExtensionIdentifierKey</key>
+			<string>public.vcs.git</string>
+			<key>IDESourceControlWCCIdentifierKey</key>
+			<string>922DEEC8B722BFB3865485680EBE965F5270D110</string>
+			<key>IDESourceControlWCCName</key>
+			<string>EETool</string>
+		</dict>
+	</array>
+</dict>
+</plist>