diff --git a/backend/auspost.c b/backend/auspost.c
index f820dbf6..8a63ea41 100644
--- a/backend/auspost.c
+++ b/backend/auspost.c
@@ -49,7 +49,7 @@ void rs_error(char data_pattern[])
 
 	int reader, triple_writer;
 	char triple[31], inv_triple[31];
-	char result[5];
+	unsigned char result[5];
 
 	triple_writer = 0;
 
@@ -85,7 +85,7 @@ void rs_error(char data_pattern[])
 
 	rs_init_gf(0x43);
 	rs_init_code(4, 1);
-	rs_encode(triple_writer, inv_triple, result);
+	rs_encode(triple_writer, (unsigned char*) inv_triple, result);
 
 	for(reader = 4; reader > 0; reader--)
 	{
@@ -157,7 +157,7 @@ int australia_post(struct zint_symbol *symbol, unsigned char source[])
 		dpid[loopey] = source[loopey];
 	}
 	dpid[8] = '\0';
-	errno = is_sane(NESET, dpid);
+	errno = is_sane(NESET, (unsigned char*)dpid);
 	if(errno == ERROR_INVALID_DATA) {
 		strcpy(symbol->errtxt, "error: invalid characters in DPID");
 		return errno;
diff --git a/backend/blockf.c b/backend/blockf.c
index ef588f4d..fc47688e 100644
--- a/backend/blockf.c
+++ b/backend/blockf.c
@@ -104,7 +104,7 @@ int data_encode_blockf(unsigned char source[], int subset_selector[], int blockm
 	column_position = 0;
 	input_position = 0;
 	done = 0;
-	
+	c = 0;
 	do {
 		done = 0;
 		/* 'done' ensures that the instructions are followed in the correct order for each input character */
diff --git a/backend/code16k.c b/backend/code16k.c
index 840eec19..9bcf2469 100644
--- a/backend/code16k.c
+++ b/backend/code16k.c
@@ -69,7 +69,7 @@ int parunmodd(unsigned char llyth);
 void grwp(int *indexliste);
 void dxsmooth(int *indexliste);
 
-void c16k_set_a(unsigned char source, int values[], int *bar_chars)
+void c16k_set_a(unsigned char source, unsigned int values[], unsigned int *bar_chars)
 {
 	if(source > 127) {
 		if(source < 160) {
@@ -87,7 +87,7 @@ void c16k_set_a(unsigned char source, int values[], int *bar_chars)
 	(*bar_chars)++;
 }
 
-void c16k_set_b(unsigned char source, int values[], int *bar_chars)
+void c16k_set_b(unsigned char source, unsigned int values[], unsigned int *bar_chars)
 {
 	if(source > 127) {
 		values[(*bar_chars)] = source - 32 - 128;
@@ -97,7 +97,7 @@ void c16k_set_b(unsigned char source, int values[], int *bar_chars)
 	(*bar_chars)++;
 }
 
-void c16k_set_c(unsigned char source_a, unsigned char source_b, int values[], int *bar_chars)
+void c16k_set_c(unsigned char source_a, unsigned char source_b, unsigned int values[], unsigned int *bar_chars)
 {
 	int weight;
 
diff --git a/backend/composite.c b/backend/composite.c
index d620487c..3a3e3b2c 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -45,9 +45,15 @@
 #include "large.h"
 #include "composite.h"
 #include "pdf417.h"
+
 #define UINT unsigned short
 
 int general_rules(char field[], char type[]);
+int eanx(struct zint_symbol *symbol, unsigned char source[]);
+int ean_128(struct zint_symbol *symbol, unsigned char source[]);
+int rss14(struct zint_symbol *symbol, unsigned char source[]);
+int rsslimited(struct zint_symbol *symbol, unsigned char source[]);
+int rssexpanded(struct zint_symbol *symbol, unsigned char source[]);
 
 static UINT pwr928[69][7];
 
@@ -117,7 +123,9 @@ int cc_a(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 	UINT codeWords[28];
 	UINT bitStr[13];
 	char codebarre[100], pattern[580];
-	
+
+	variant=0;
+
 	for(i = 0; i < 13; i++) { bitStr[i] = 0; }
 	for(i = 0; i < 28; i++) { codeWords[i] = 0; }
 	
@@ -701,7 +709,9 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 	alpha_pad = 0;
 	ai90_mode = 0;
 	*(ecc) = 0;
-	
+	value = 0;
+	target_bitsize = 0;
+
 	if((source[0] == '1') && ((source[1] == '0') || (source[1] == '1') || (source[1] == '7')) && (ustrlen(source) > 8)) {
 		/* Source starts (10), (11) or (17) */
 		encoding_method = 2;
@@ -1663,7 +1673,8 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 {
 	int errno, cc_mode, cc_width, ecc_level;
 	int j, last_ai, ai_latch, i, k, separator_row;
-	char reduced[3000], binary_string[10 * ustrlen(source)], ai_string[4];
+	unsigned char reduced[3000];
+	char binary_string[10 * ustrlen(source)], ai_string[4];
 	struct zint_symbol *linear;
 	int top_shift, bottom_shift;
 	
@@ -1758,16 +1769,16 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 	}
 	
 	switch(symbol->symbology) {
-		case BARCODE_EANX_CC: errno = eanx(linear, symbol->primary); break;
-		case BARCODE_EAN128_CC: errno = ean_128(linear, symbol->primary); break;
-		case BARCODE_RSS14_CC: errno = rss14(linear, symbol->primary); break;
-		case BARCODE_RSS_LTD_CC: errno = rsslimited(linear, symbol->primary); break;
-		case BARCODE_RSS_EXP_CC: errno = rssexpanded(linear, symbol->primary); break;
-		case BARCODE_UPCA_CC: errno = eanx(linear, symbol->primary); break;
-		case BARCODE_UPCE_CC: errno = eanx(linear, symbol->primary); break;
-		case BARCODE_RSS14STACK_CC: errno = rss14(linear, symbol->primary); break;
-		case BARCODE_RSS14_OMNI_CC: errno = rss14(linear, symbol->primary); break;
-		case BARCODE_RSS_EXPSTACK_CC: errno = rssexpanded(linear, symbol->primary); break;
+		case BARCODE_EANX_CC: errno = eanx(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_EAN128_CC: errno = ean_128(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS14_CC: errno = rss14(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS_LTD_CC: errno = rsslimited(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS_EXP_CC: errno = rssexpanded(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_UPCA_CC: errno = eanx(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_UPCE_CC: errno = eanx(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS14STACK_CC: errno = rss14(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS14_OMNI_CC: errno = rss14(linear, (unsigned char *)symbol->primary); break;
+		case BARCODE_RSS_EXPSTACK_CC: errno = rssexpanded(linear, (unsigned char *)symbol->primary); break;
 	}
 	
 	switch(symbol->symbology) {
@@ -1816,7 +1827,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 			if(symbol->symbology != BARCODE_EAN128_CC) {
 				return ERROR_TOO_LONG;
 			} else {
-				cc_mode == 3;
+				cc_mode = 3;
 			}
 		}
 	}
@@ -1830,9 +1841,9 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 	}
 	
 	switch(cc_mode) { /* Note that ecc_level is only relevant to CC-C */
-		case 1: errno = cc_a(symbol, binary_string, cc_width); break;
-		case 2: errno = cc_b(symbol, binary_string, cc_width); break;
-		case 3: errno = cc_c(symbol, binary_string, cc_width, ecc_level); break;
+		case 1: errno = cc_a(symbol, (unsigned char*)binary_string, cc_width); break;
+		case 2: errno = cc_b(symbol, (unsigned char*)binary_string, cc_width); break;
+		case 3: errno = cc_c(symbol, (unsigned char*)binary_string, cc_width, ecc_level); break;
 	}
 	
 	if(errno != 0) {
diff --git a/backend/imail.c b/backend/imail.c
index fe4cc6e8..7facb746 100644
--- a/backend/imail.c
+++ b/backend/imail.c
@@ -518,7 +518,7 @@ int imail(struct zint_symbol *symbol, unsigned char source[])
 	accum[103] = 0;
 	accum[102] = 0;
 	
-	strcpy(byte_array, "");
+	memset(byte_array, 0, 13);
 	for(j = 0; j < 13; j++) {
 		i = 96 - (8 * j);
 		byte_array[j] = 0;
diff --git a/backend/maxicode.c b/backend/maxicode.c
index 03f76458..c5d03e3d 100644
--- a/backend/maxicode.c
+++ b/backend/maxicode.c
@@ -32,8 +32,8 @@ int maxi_codeword[144];
 void maxi_do_primary_check(  )
 {
 	/* Handles error correction of primary message */
-	char data[15];
-	char results[15];
+	unsigned char data[15];
+	unsigned char results[15];
 	int j;
 	int datalen = 10;
 	int ecclen = 10;
@@ -53,8 +53,8 @@ void maxi_do_primary_check(  )
 void maxi_do_secondary_chk_odd( int ecclen )
 {
 	/* Handles error correction of odd characters in secondary */
-	char data[100];
-	char results[30];
+	unsigned char data[100];
+	unsigned char results[30];
 	int j;
 	int datalen = 68;
 	
@@ -77,8 +77,8 @@ void maxi_do_secondary_chk_odd( int ecclen )
 void maxi_do_secondary_chk_even(int ecclen )
 {
 	/* Handles error correction of even characters in secondary */
-	char data[100];
-	char results[30];
+	unsigned char data[100];
+	unsigned char results[30];
 	int j;
 	int datalen = 68;
 
@@ -418,7 +418,7 @@ int maxi_text_process(int mode, unsigned char source[])
 	do {
 		if (set[i] == 6) {
 			/* Number compression */
-			char substring[10];
+			char substring[11];
 			int value;
 			
 			for(j = 0; j < 10; j++) {
@@ -517,7 +517,7 @@ void maxi_do_primary_3(char postcode[], int country, int service)
 	/* Format structured primary for Mode 3 */
 	int i;
 
-	to_upper(postcode);
+	to_upper((unsigned char*)postcode);
 	for(i = 0; i < strlen(postcode); i++) {
 		if((postcode[i] >= 65) && (postcode[i] <= 90)) {
 			/* (Capital) letters shifted to Code Set A values */
diff --git a/backend/pdf417.c b/backend/pdf417.c
index 69dab2e9..bdc95a36 100644
--- a/backend/pdf417.c
+++ b/backend/pdf417.c
@@ -43,6 +43,21 @@
    original Visual Basic source code file pdf417.frm
    this code retains some original (French) procedure and variable names to ease conversion */
 
+/* text mode processing tables */
+static int asciix[95] = { 7, 8, 8, 4, 12, 4, 4, 8, 8, 8, 12, 4, 12, 12, 12, 12, 4, 4, 4, 4, 4, 4, 4, 4,
+	4, 4, 12, 8, 8, 4, 8, 8, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 1, 1, 8, 8, 8, 4, 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 8, 8, 8, 8 };
+static int asciiy[95] = { 26, 10, 20, 15, 18, 21, 10, 28, 23, 24, 22, 20, 13, 16, 17, 19, 0, 1, 2, 3,
+	4, 5, 6, 7, 8, 9, 14, 0, 1, 23, 2, 25, 3, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+	16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 4, 5, 6, 24, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+	11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 21, 27, 9 };
+
+/* Automatic sizing table */
+static int MicroAutosize[56] =
+{	4, 6, 7, 8, 10, 12, 13, 14, 16, 18, 19, 20, 24, 29, 30, 33, 34, 37, 39, 46, 54, 58, 70, 72, 82, 90, 108, 126,
+	1, 14, 2, 7, 3, 25, 8, 16, 5, 17, 9, 6, 10, 11, 28, 12, 19, 13, 29, 20, 30, 21, 22, 31, 23, 32, 33, 34
+};
 
 
 int liste[2][1000]; /* global - okay, so I got _almost_ everything local! */
@@ -492,13 +507,13 @@ int pdf417(struct zint_symbol *symbol, unsigned char chaine[])
 	for(i = 0; i < indexliste; i++) {
 		switch(liste[1][i]) {
 			case TEX: /* 547 - text mode */
-				textprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
+				textprocess(chainemc, &mclength, (char*)chaine, indexchaine, liste[0][i], i);
 				break;
 			case BYT: /* 670 - octet stream mode */
 				byteprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
 				break;
 			case NUM: /* 712 - numeric mode */
-				numbprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
+				numbprocess(chainemc, &mclength, (char*)chaine, indexchaine, liste[0][i], i);
 				break;
 		}
 		indexchaine = indexchaine + liste[0][i];
@@ -777,13 +792,13 @@ int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[])
 	for(i = 0; i < indexliste; i++) {
 		switch(liste[1][i]) {
 			case TEX: /* 547 - text mode */
-				textprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
+				textprocess(chainemc, &mclength, (char*)chaine, indexchaine, liste[0][i], i);
 				break;
 			case BYT: /* 670 - octet stream mode */
 				byteprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
 				break;
 			case NUM: /* 712 - numeric mode */
-				numbprocess(chainemc, &mclength, chaine, indexchaine, liste[0][i], i);
+				numbprocess(chainemc, &mclength, (char*)chaine, indexchaine, liste[0][i], i);
 				break;
 		}
 		indexchaine = indexchaine + liste[0][i];
diff --git a/backend/pdf417.h b/backend/pdf417.h
index da62c2b5..4eea4443 100644
--- a/backend/pdf417.h
+++ b/backend/pdf417.h
@@ -31,16 +31,6 @@
 
 #define BRSET "ABCDEFabcdefghijklmnopqrstuvwxyz*+-"
 
-/* text mode processing tables */
-static int asciix[95] = { 7, 8, 8, 4, 12, 4, 4, 8, 8, 8, 12, 4, 12, 12, 12, 12, 4, 4, 4, 4, 4, 4, 4, 4,
-	4, 4, 12, 8, 8, 4, 8, 8, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1, 1, 1, 1, 8, 8, 8, 4, 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-	2, 2, 2, 2, 8, 8, 8, 8 };
-static int asciiy[95] = { 26, 10, 20, 15, 18, 21, 10, 28, 23, 24, 22, 20, 13, 16, 17, 19, 0, 1, 2, 3,
-	4, 5, 6, 7, 8, 9, 14, 0, 1, 23, 2, 25, 3, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-	16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 4, 5, 6, 24, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
-	11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 21, 27, 9 };
-	
 /* PDF417 error correction coefficients from Grand Zebu */
 static int coefrs[1022] = {
 	/* k = 2 */
@@ -422,12 +412,6 @@ static int MicroVariants[170] =
 	0, 0, 0, 7, 7, 7, 7, 15, 15, 24, 34, 57, 84, 45, 70, 99, 115, 133, 154, 180, 212, 250, 294, 7, 45, 70, 99, 115, 133, 154, 180, 212, 250, 294 };
 /* rows, columns, error codewords, k-offset */
 
-/* Automatic sizing table */
-static int MicroAutosize[56] =
-{	4, 6, 7, 8, 10, 12, 13, 14, 16, 18, 19, 20, 24, 29, 30, 33, 34, 37, 39, 46, 54, 58, 70, 72, 82, 90, 108, 126,
-	1, 14, 2, 7, 3, 25, 8, 16, 5, 17, 9, 6, 10, 11, 28, 12, 19, 13, 29, 20, 30, 21, 22, 31, 23, 32, 33, 34
-};
-
 /* following is Left RAP, Centre RAP, Right RAP and Start Cluster from ISO/IEC 24728:2006 tables 10, 11 and 12 */
 static int RAPTable[136] =
 {	1, 8, 36, 19, 9, 25, 1, 1, 8, 36, 19, 9, 27, 1, 7, 15, 25, 37, 1, 1, 21, 15, 1, 47, 1, 7, 15, 25, 37, 1, 1, 21, 15, 1,
diff --git a/backend/png.c b/backend/png.c
index 342fe643..4941258e 100644
--- a/backend/png.c
+++ b/backend/png.c
@@ -80,8 +80,8 @@ int png_to_file(struct zint_symbol *symbol, int image_height, int image_width, c
 	}
 	
 	/* sort out colour options */
-	to_upper(symbol->fgcolour);
-	to_upper(symbol->bgcolour);
+	to_upper((unsigned char*)symbol->fgcolour);
+	to_upper((unsigned char*)symbol->bgcolour);
 	
 	if(strlen(symbol->fgcolour) != 6) {
 		strcpy(symbol->errtxt, "error: malformed foreground colour target");
@@ -91,12 +91,12 @@ int png_to_file(struct zint_symbol *symbol, int image_height, int image_width, c
 		strcpy(symbol->errtxt, "error: malformed background colour target");
 		return ERROR_INVALID_OPTION;
 	}
-	errno = is_sane(SSET, symbol->fgcolour);
+	errno = is_sane(SSET, (unsigned char*)symbol->fgcolour);
 	if (errno == ERROR_INVALID_DATA) {
 		strcpy(symbol->errtxt, "error: malformed foreground colour target");
 		return ERROR_INVALID_OPTION;
 	}
-	errno = is_sane(SSET, symbol->bgcolour);
+	errno = is_sane(SSET, (unsigned char*)symbol->bgcolour);
 	if (errno == ERROR_INVALID_DATA) {
 		strcpy(symbol->errtxt, "error: malformed background colour target");
 		return ERROR_INVALID_OPTION;
@@ -350,12 +350,12 @@ void draw_letter(char *pixelbuf, unsigned char letter, int xposn, int yposn, int
 	}
 }
 
-void draw_string(char *pixbuf, unsigned char input_string[], int xposn, int yposn, int image_width, int image_height)
+void draw_string(char *pixbuf, char input_string[], int xposn, int yposn, int image_width, int image_height)
 {
 	/* Plot a string into the pixel buffer */
 	int i, string_length, string_left_hand;
 	
-	string_length = ustrlen(input_string);
+	string_length = strlen(input_string);
 	string_left_hand = xposn - ((7 * string_length) / 2);
 	
 	for(i = 0; i < string_length; i++) {
@@ -424,7 +424,8 @@ int png_plot(struct zint_symbol *symbol, int rotate_angle)
 	strcpy(addon, "");
 	comp_offset = 0;
 	addon_text_posn = 0.0;
-	
+	row_height = 0;
+
 	if (symbol->height == 0) {
 		symbol->height = 50;
 	}
diff --git a/backend/ps.c b/backend/ps.c
index ad3504b5..0aca6cb7 100644
--- a/backend/ps.c
+++ b/backend/ps.c
@@ -43,6 +43,7 @@ int ps_plot(struct zint_symbol *symbol)
 	int large_bar_count, comp_offset;
 	float addon_text_posn;
 	
+	row_height=0;
 	textdone = 0;
 	main_width = symbol->width;
 	strcpy(addon, "");
@@ -56,8 +57,8 @@ int ps_plot(struct zint_symbol *symbol)
 	}
 	
 	/* sort out colour options */
-	to_upper(symbol->fgcolour);
-	to_upper(symbol->bgcolour);
+	to_upper((unsigned char*)symbol->fgcolour);
+	to_upper((unsigned char*)symbol->bgcolour);
 	
 	if(strlen(symbol->fgcolour) != 6) {
 		strcpy(symbol->errtxt, "error: malformed foreground colour target");
@@ -67,12 +68,12 @@ int ps_plot(struct zint_symbol *symbol)
 		strcpy(symbol->errtxt, "error: malformed background colour target");
 		return ERROR_INVALID_OPTION;
 	}
-	error_number = is_sane(SSET, symbol->fgcolour);
+	error_number = is_sane(SSET, (unsigned char*)symbol->fgcolour);
 	if (error_number == ERROR_INVALID_DATA) {
 		strcpy(symbol->errtxt, "error: malformed foreground colour target");
 		return ERROR_INVALID_OPTION;
 	}
-	error_number = is_sane(SSET, symbol->bgcolour);
+	error_number = is_sane(SSET, (unsigned char*)symbol->bgcolour);
 	if (error_number == ERROR_INVALID_DATA) {
 		strcpy(symbol->errtxt, "error: malformed background colour target");
 		return ERROR_INVALID_OPTION;
@@ -166,7 +167,7 @@ int ps_plot(struct zint_symbol *symbol)
 	yoffset = symbol->border_width;
 	
 	/* Start writing the header */
-	fprintf(feps, "%!PS-Adobe-3.0 EPSF-3.0\n");
+	fprintf(feps, "%%!PS-Adobe-3.0 EPSF-3.0\n");
 	fprintf(feps, "%%%%Creator: Zint %s\n", ZINT_VERSION);
 	if(strlen(symbol->text) != 0) {
 		fprintf(feps, "%%%%Title: %s\n",symbol->text);
diff --git a/backend/qr.c b/backend/qr.c
index 6ee35055..071ec417 100644
--- a/backend/qr.c
+++ b/backend/qr.c
@@ -35,6 +35,8 @@ QRcode *encode(int security, int size, const unsigned char *intext)
 	QRencodeMode hint;
 	QRcode *code;
 
+	level=QR_ECLEVEL_L;
+
 	if(kanji) {
 		hint = QR_MODE_KANJI;
 	} else {
@@ -58,7 +60,7 @@ QRcode *encode(int security, int size, const unsigned char *intext)
 		version = 0;
 	}
 
-	code = QRcode_encodeString(intext, version, level, hint, 1);
+	code = QRcode_encodeString((char*)intext, version, level, hint, 1);
 
 	return code;
 }
diff --git a/frontend/main.c b/frontend/main.c
index ef0aa82e..407b6499 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -321,7 +321,7 @@ int main(int argc, char **argv)
 				break;
 				
 			case 'd': /* we have some data! */
-				error_number = data_process(my_symbol, optarg, rotate_angle);
+				error_number = data_process(my_symbol, (unsigned char*)optarg, rotate_angle);
 				if(error_number != 0) {
 					printf("%s\n", my_symbol->errtxt);
 					ZBarcode_Delete(my_symbol);