diff --git a/NXDNCRC.cpp b/NXDNCRC.cpp
index 0e2ad06..a065759 100644
--- a/NXDNCRC.cpp
+++ b/NXDNCRC.cpp
@@ -17,6 +17,7 @@
  */
 
 #include "NXDNCRC.h"
+#include "Log.h"
 
 #include <cstdio>
 #include <cassert>
@@ -28,6 +29,7 @@ const uint16_t BIT_MASK_TABLE2[] = { 0x8000U, 0x4000U, 0x2000U, 0x1000U, 0x0800U
 #define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE1[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE1[(i)&7])
 #define READ_BIT1(p,i)    (p[(i)>>3] & BIT_MASK_TABLE1[(i)&7])
 
+#define WRITE_BIT2(p,i,b) p[(i)>>4] = (b) ? (p[(i)>>4] | BIT_MASK_TABLE2[(i)&15]) : (p[(i)>>3] & ~BIT_MASK_TABLE2[(i)&15])
 #define READ_BIT2(p,i)    (p[(i)>>4] & BIT_MASK_TABLE2[(i)&15])
 
 bool CNXDNCRC::checkCRC6(const unsigned char* in, unsigned int length)
@@ -37,6 +39,16 @@ bool CNXDNCRC::checkCRC6(const unsigned char* in, unsigned int length)
 	uint8_t crc[1U];
 	crc[0U] = createCRC6(in, length);
 
+	uint8_t temp[1U];
+	temp[0U] = 0x00U;
+	unsigned int j = length;
+	for (unsigned int i = 0U; i < 6U; i++, j++) {
+		bool b = READ_BIT1(in, j);
+		WRITE_BIT1(temp, i, b);
+	}
+
+	LogMessage("NXDN, CRC6: new:%02X old:%02X", crc[0U], temp[0U]);
+
 	unsigned int n = length;
 	for (unsigned int i = 0U; i < 6U; i++, n++) {
 		bool b1 = READ_BIT1(crc, i);
@@ -69,6 +81,16 @@ bool CNXDNCRC::checkCRC12(const unsigned char* in, unsigned int length)
 	uint16_t crc[1U];
 	crc[0U] = createCRC12(in, length);
 
+	uint16_t temp[1U];
+	temp[0U] = 0x00U;
+	unsigned int j = length;
+	for (unsigned int i = 0U; i < 12U; i++, j++) {
+		bool b = READ_BIT1(in, j);
+		WRITE_BIT2(temp, i, b);
+	}
+
+	LogMessage("NXDN, CRC12: new:%04X old:%04X", crc[0U], temp[0U]);
+
 	unsigned int n = length;
 	for (unsigned int i = 0U; i < 12U; i++, n++) {
 		bool b1 = READ_BIT2(crc, i);
@@ -101,6 +123,16 @@ bool CNXDNCRC::checkCRC15(const unsigned char* in, unsigned int length)
 	uint16_t crc[1U];
 	crc[0U] = createCRC15(in, length);
 
+	uint16_t temp[1U];
+	temp[0U] = 0x00U;
+	unsigned int j = length;
+	for (unsigned int i = 0U; i < 15U; i++, j++) {
+		bool b = READ_BIT1(in, j);
+		WRITE_BIT2(temp, i, b);
+	}
+
+	LogMessage("NXDN, CRC15: new:%04X old:%04X", crc[0U], temp[0U]);
+
 	unsigned int n = length;
 	for (unsigned int i = 0U; i < 15U; i++, n++) {
 		bool b1 = READ_BIT2(crc, i);
@@ -128,93 +160,54 @@ void CNXDNCRC::encodeCRC15(unsigned char* in, unsigned int length)
 
 uint8_t CNXDNCRC::createCRC6(const unsigned char* in, unsigned int length)
 {
-	uint8_t crc = 0x3EU;
+	uint8_t crc = 0x3FU;
 
 	for (unsigned int i = 0U; i < length; i++) {
 		bool bit1 = READ_BIT1(in, i) != 0x00U;
 		bool bit2 = (crc & 0x20U) == 0x20U;
 
 		crc <<= 1;
-
-		if (bit1)
-			crc |= 0x01U;
-
-		if (bit2)
-			crc ^= 0x27U;
-
 		crc &= 0x3FU;
-	}
 
-	for (unsigned int i = 0U; i < 6U; i++) {
-		bool bit = (crc & 0x20U) == 0x20U;
-
-		crc <<= 1;
-
-		if (bit)
+		if (bit1 ^ bit2)
 			crc ^= 0x27U;
 	}
 
-	return (crc & 0x3FU) << 2U;
+	return crc & 0x3FU;
 }
 
 uint16_t CNXDNCRC::createCRC12(const unsigned char* in, unsigned int length)
 {
-	uint16_t crc = 0x0D9EU;
+	uint16_t crc = 0x0FFFU;
 
 	for (unsigned int i = 0U; i < length; i++) {
 		bool bit1 = READ_BIT1(in, i) != 0x00U;
 		bool bit2 = (crc & 0x0800U) == 0x0800U;
 
 		crc <<= 1;
-
-		if (bit1)
-			crc |= 0x0001U;
-
-		if (bit2)
-			crc ^= 0x080FU;
-
 		crc &= 0x0FFFU;
-	}
 
-	for (unsigned int i = 0U; i < 12U; i++) {
-		bool bit = (crc & 0x0800U) == 0x0800U;
-
-		crc <<= 1;
-
-		if (bit)
+		if (bit1 ^ bit2)
 			crc ^= 0x080FU;
 	}
 
-	return (crc & 0x0FFFU) << 4U;
+	return crc & 0x0FFFU;
 }
 
 uint16_t CNXDNCRC::createCRC15(const unsigned char* in, unsigned int length)
 {
-	uint16_t crc = 0x02E4U;
+	uint16_t crc = 0x7FFFU;
 
 	for (unsigned int i = 0U; i < length; i++) {
 		bool bit1 = READ_BIT1(in, i) != 0x00U;
 		bool bit2 = (crc & 0x4000U) == 0x4000U;
 
 		crc <<= 1;
-
-		if (bit1)
-			crc |= 0x0001U;
-
-		if (bit2)
-			crc ^= 0x4CC5U;
-
 		crc &= 0x7FFFU;
-	}
 
-	for (unsigned int i = 0U; i < 15U; i++) {
-		bool bit = (crc & 0x4000U) == 0x4000U;
-
-		crc <<= 1;
-
-		if (bit)
+		if (bit1 ^ bit2)
 			crc ^= 0x4CC5U;
 	}
 
-	return (crc & 0x7FFFU) << 1U;
+	return crc & 0x7FFFU;
 }