diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 2e16f62930..d43ee337aa 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -16,6 +16,24 @@
    The license applies to all entries newer than 2009-04-28.
 */
 
+2010-11-17 12:19 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/contrib/hbzebra/pdf417.c
+  * harbour/contrib/hbzebra/code128.c
+  * harbour/contrib/hbzebra/eanupc.c
+  * harbour/contrib/hbzebra/code11.c
+  * harbour/contrib/hbzebra/itf.c
+  * harbour/contrib/hbzebra/datamtrx.c
+  * harbour/contrib/hbzebra/code39.c
+  * harbour/contrib/hbzebra/code93.c
+  * harbour/contrib/hbzebra/codabar.c
+    % added const to all static table declarations and updated
+      code to use const pointers to them. Please remember that
+      memory regions declared as const can be better optimized
+      by compiler during compilation and on some machines also
+      on runtime because can be located in readonly area which
+      is cached in more efficient way.
+    ! fixed some non const declarations for pure "..." strings
+
 2010-11-17 12:03 UTC+0100 Viktor Szakats (harbour.01 syenar.hu)
   * examples/terminal/trm_srv.prg
   * examples/terminal/readme.txt
diff --git a/harbour/contrib/hbzebra/codabar.c b/harbour/contrib/hbzebra/codabar.c
index 8c23947115..90c468284c 100644
--- a/harbour/contrib/hbzebra/codabar.c
+++ b/harbour/contrib/hbzebra/codabar.c
@@ -55,7 +55,7 @@
 #include "hbapierr.h"
 
 
-static char s_code[] = {
+static const char s_code[] = {
    0x60,   /* 0 */
    0x30,   /* 1 */
    0x48,   /* 2 */
@@ -79,13 +79,13 @@ static char s_code[] = {
 
 static int _codabar_charno( char ch )
 {
-   static char * s_symbols = "-$:/.+ABCD";
+   static const char * s_symbols = "-$:/.+ABCD";
 
    if( '0' <= ch && ch <= '9' )
       return ch - '0';
    else
    {
-      char * ptr = strchr( s_symbols, ch );
+      const char * ptr = strchr( s_symbols, ch );
       if( ptr && *ptr )
          return ptr - s_symbols + 10;
    }
diff --git a/harbour/contrib/hbzebra/code11.c b/harbour/contrib/hbzebra/code11.c
index 8722725c97..275a691231 100644
--- a/harbour/contrib/hbzebra/code11.c
+++ b/harbour/contrib/hbzebra/code11.c
@@ -54,7 +54,7 @@
 #include "hbapiitm.h"
 #include "hbapierr.h"
 
-static char s_code[] = {
+static const char s_code[] = {
    0x10,  /* 0 */
    0x11,  /* 1 */
    0x12,  /* 2 */
@@ -140,7 +140,7 @@ PHB_ZEBRA hb_zebra_create_code11( const char * szCode, HB_SIZE nLen, int iFlags
    _code11_add( pZebra->pBits, s_code[ 11 ], iFlags, HB_FALSE );  /* start */
 
    csum = ksum = 0;
-   for( i = 0; i < iLen; i++ )  
+   for( i = 0; i < iLen; i++ )
    {
       int no = _code11_charno( szCode[ i ] );
       _code11_add( pZebra->pBits, s_code[ no ], iFlags, HB_FALSE );
diff --git a/harbour/contrib/hbzebra/code128.c b/harbour/contrib/hbzebra/code128.c
index 7bc4a9cc0e..e739e60cc8 100644
--- a/harbour/contrib/hbzebra/code128.c
+++ b/harbour/contrib/hbzebra/code128.c
@@ -1,4 +1,4 @@
-/*          
+/*
  * $Id$
  */
 
@@ -55,7 +55,7 @@
 #include "hbapierr.h"
 
 
-static unsigned short s_code[] = {
+static const unsigned short s_code[] = {
    00633,   /*            00  */
    00663,   /*  !    !    01  */
    01463,   /*  "    "    02  */
@@ -159,8 +159,8 @@ static unsigned short s_code[] = {
    01675,   /*  CodB FNC4 CodB 100 */
    01727,   /*  FNC4 CodA CodA 101 */
    01657,   /*  FNC1 FNC1 FNC1 102 */
-   00413,   /*  Start Code A   103 */    
-   00113,   /*  Start Code B   104 */    
+   00413,   /*  Start Code A   103 */
+   00113,   /*  Start Code B   104 */
    00713};  /*  Start Code C   105 */
 
 #define CODESET_A       0
@@ -179,9 +179,8 @@ static unsigned short s_code[] = {
 
 static int _code128_charno( char ch, int iCodeSet )
 {
-
    if( iCodeSet == CODESET_A )
-   { 
+   {
       if( ch >= ' ' && ch <= '_' )
          return ch - ' ';
       else if( ( unsigned char ) ch <= 31 )
@@ -373,7 +372,7 @@ PHB_ZEBRA hb_zebra_create_code128( const char * szCode, HB_SIZE nLen, int iFlags
 
    pZebra->pBits = hb_bitbuffer_create();
    csum = pCode[ 0 ];
-   for( i = 0; i < iCodeLen; i++ )  
+   for( i = 0; i < iCodeLen; i++ )
    {
       hb_bitbuffer_cat_int( pZebra->pBits, s_code[ pCode[ i ] ], 11 );
       csum += i * pCode[ i ];
diff --git a/harbour/contrib/hbzebra/code39.c b/harbour/contrib/hbzebra/code39.c
index 470357317f..b8c5e598de 100644
--- a/harbour/contrib/hbzebra/code39.c
+++ b/harbour/contrib/hbzebra/code39.c
@@ -57,7 +57,7 @@
 
 /* Usually one character bitmap does not fit into 1 byte, but if we use enough
    good encoding, we can manage to fit :) [Mindaugas] */
-static HB_UCHAR s_code[] =
+static const HB_UCHAR s_code[] =
 {
    0x58,   /* 0 */
    0x09,   /* 1 */
@@ -105,7 +105,7 @@ static HB_UCHAR s_code[] =
 
 static int _code39_charno( char ch )
 {
-   static char * s_symbols = "-. $/+%";
+   static const char * s_symbols = "-. $/+%";
 
    if( '0' <= ch && ch <= '9' )
       return ch - '0';
@@ -113,7 +113,7 @@ static int _code39_charno( char ch )
       return ch - 'A' + 10;
    else
    {
-      char * ptr = strchr( s_symbols, ch );
+      const char * ptr = strchr( s_symbols, ch );
       if( ptr && *ptr )
          return ptr - s_symbols + 36;
    }
diff --git a/harbour/contrib/hbzebra/code93.c b/harbour/contrib/hbzebra/code93.c
index 0fa4976f12..1653665213 100644
--- a/harbour/contrib/hbzebra/code93.c
+++ b/harbour/contrib/hbzebra/code93.c
@@ -55,7 +55,7 @@
 #include "hbapierr.h"
 
 
-static char s_code[] = {
+static const char s_code[] = {
    0x28,  /* 0 */
    0x12,  /* 1 */
    0x22,  /* 2 */
@@ -107,7 +107,7 @@ static char s_code[] = {
 
 static int _code93_charno( char ch )
 {
-   static char * s_symbols = "-. $/+%";
+   static const char * s_symbols = "-. $/+%";
 
    if( '0' <= ch && ch <= '9' )
       return ch - '0';
@@ -115,10 +115,10 @@ static int _code93_charno( char ch )
       return ch - 'A' + 10;
    else
    {
-      char * ptr = strchr( s_symbols, ch );
+      const char * ptr = strchr( s_symbols, ch );
       if( ptr && *ptr )
          return ptr - s_symbols + 36;
-   } 
+   }
    return -1;
 }
 
@@ -166,7 +166,7 @@ PHB_ZEBRA hb_zebra_create_code93( const char * szCode, HB_SIZE nLen, int iFlags
    csum = 0;
    ksum = 0;
    k++;
-   for( i = 0; i < iLen; i++ )  
+   for( i = 0; i < iLen; i++ )
    {
       int no = _code93_charno( szCode[ i ] );
       if( no >= 0 )
diff --git a/harbour/contrib/hbzebra/datamtrx.c b/harbour/contrib/hbzebra/datamtrx.c
index e95cd13fa4..359bd0e178 100644
--- a/harbour/contrib/hbzebra/datamtrx.c
+++ b/harbour/contrib/hbzebra/datamtrx.c
@@ -92,7 +92,7 @@ typedef struct
 } DATAMATRIX_SIZE, * PDATAMATRIX_SIZE;
 
 
-static DATAMATRIX_SIZE s_size[ SIZE_COUNT ] = {
+static const DATAMATRIX_SIZE s_size[ SIZE_COUNT ] = {
    { 10,  10,  10,  10,    3,    3,    5 },
    { 12,  12,  12,  12,    5,    5,    7 },
    {  8,  18,   8,  18,    5,    5,    7 },
@@ -178,7 +178,7 @@ static void _reed_solomon_encode( unsigned char * pData, int iDataLen, unsigned
    }
 }
 
-static void _datamatrix_reed_solomon( char * pData, PDATAMATRIX_SIZE pSize )
+static void _datamatrix_reed_solomon( char * pData, const DATAMATRIX_SIZE * pSize )
 {
    int * pPoly, * pExp, * pLog;
    int i, j, iBits, iMod, iPoly, iECLen, iIndex, iBlocks;
@@ -325,7 +325,7 @@ static void _datamatrix_place_d( int * pArr, int iPRow, int iPCol, int iIndex )
    _datamatrix_place_bit( pArr, iPRow, iPCol,         1, iPCol - 1, ( iIndex << 3 ) + 0 );
 }
 
-static void _datamatrix_do_placement( PHB_BITBUFFER pBits, char * pCW, PDATAMATRIX_SIZE pSize )
+static void _datamatrix_do_placement( PHB_BITBUFFER pBits, char * pCW, const DATAMATRIX_SIZE * pSize )
 {
    int * pArr;
    int i, iR, iC, iPRow, iPCol;
@@ -403,7 +403,7 @@ static void _datamatrix_do_placement( PHB_BITBUFFER pBits, char * pCW, PDATAMATR
 PHB_ZEBRA hb_zebra_create_datamatrix( const char * szCode, HB_SIZE nLen, int iFlags )
 {
    PHB_ZEBRA  pZebra;
-   PDATAMATRIX_SIZE pSize;
+   const DATAMATRIX_SIZE * pSize;
    char *     pCW;
    int        i, j, iDataCount, iErrorSize, iLen = ( int ) nLen;
 
diff --git a/harbour/contrib/hbzebra/eanupc.c b/harbour/contrib/hbzebra/eanupc.c
index 8addabf38b..7083a93588 100644
--- a/harbour/contrib/hbzebra/eanupc.c
+++ b/harbour/contrib/hbzebra/eanupc.c
@@ -56,16 +56,16 @@
 
 
 /* we do not store L-code, but just to bit inversion R-code to obtain it */
-static char s_first[] = { 0x00, 0x34, 0x2C, 0x1C, 0x32, 0x26, 0x0E, 0x2A, 0x1A, 0x16 };
-static char s_rcode[] = { 0x27, 0x33, 0x1B, 0x21, 0x1D, 0x39, 0x05, 0x11, 0x09, 0x17 };
-static char s_gcode[] = { 0x72, 0x66, 0x6C, 0x42, 0x5C, 0x4E, 0x50, 0x44, 0x48, 0x74 };  /* reversion of R-code */
+static const char s_first[] = { 0x00, 0x34, 0x2C, 0x1C, 0x32, 0x26, 0x0E, 0x2A, 0x1A, 0x16 };
+static const char s_rcode[] = { 0x27, 0x33, 0x1B, 0x21, 0x1D, 0x39, 0x05, 0x11, 0x09, 0x17 };
+static const char s_gcode[] = { 0x72, 0x66, 0x6C, 0x42, 0x5C, 0x4E, 0x50, 0x44, 0x48, 0x74 };  /* reversion of R-code */
 
 
 static char _ean13_checksum( const char * szCode )
 {
    int   i, sum = 0;
-   
-   for ( i = 0; i < 12; i++ )  
+
+   for ( i = 0; i < 12; i++ )
       sum += ( szCode[ i ] - '0' ) * ( i & 1 ? 3 : 1 );
    return '0' + ( 10000 - sum ) % 10;
 }
@@ -73,8 +73,8 @@ static char _ean13_checksum( const char * szCode )
 static char _ean8_checksum( const char * szCode )
 {
    int   i, sum = 0;
-   
-   for ( i = 0; i < 7; i++ )  
+
+   for ( i = 0; i < 7; i++ )
       sum += ( szCode[ i ] - '0' ) * ( i & 1 ? 1 : 3 );
    return '0' + ( 10000 - sum ) % 10;
 }
@@ -82,8 +82,8 @@ static char _ean8_checksum( const char * szCode )
 static char _upca_checksum( const char * szCode )
 {
    int   i, sum = 0;
-   
-   for ( i = 0; i < 11; i++ )  
+
+   for ( i = 0; i < 11; i++ )
       sum += ( szCode[ i ] - '0' ) * ( i & 1 ? 1 : 3 );
    return '0' + ( 10000 - sum ) % 10;
 }
diff --git a/harbour/contrib/hbzebra/itf.c b/harbour/contrib/hbzebra/itf.c
index 9b6f24d93c..6ccc70cb00 100644
--- a/harbour/contrib/hbzebra/itf.c
+++ b/harbour/contrib/hbzebra/itf.c
@@ -55,7 +55,7 @@
 #include "hbapierr.h"
 
 
-static char s_code[] = { 0x0C, 0x11, 0x12, 0x03, 0x14, 0x05, 0x06, 0x18, 0x09, 0x0A };
+static const char s_code[] = { 0x0C, 0x11, 0x12, 0x03, 0x14, 0x05, 0x06, 0x18, 0x09, 0x0A };
 
 static char _itf_checksum( const char * szCode )
 {
diff --git a/harbour/contrib/hbzebra/pdf417.c b/harbour/contrib/hbzebra/pdf417.c
index c63a5224de..419cebadc4 100644
--- a/harbour/contrib/hbzebra/pdf417.c
+++ b/harbour/contrib/hbzebra/pdf417.c
@@ -91,7 +91,7 @@
 #define MAX_CODEWORD_COUNT  928
 
 
-static short s_code[ 3 ][ 929 ] = {
+static const short s_code[ 3 ][ 929 ] = {
  {
    0x03AB, 0x0F57, 0x3EAF, 0x072B, 0x1E57, 0x7CAF, 0x0315, 0x0E2B,
    0x0615, 0x020A, 0x0C15, 0x040A, 0x03B5, 0x0F6B, 0x3ED7, 0x0735,
@@ -447,29 +447,29 @@ static short s_code[ 3 ][ 929 ] = {
    0x69C0, 0x6DE0, 0x2BE1, 0x4BE1, 0x29E0, 0x2DF0, 0x49E0, 0x4DF0,
    0x57E3 }};
 
-static unsigned short s_rs0[] = {
+static const unsigned short s_rs0[] = {
    27, 917 };
 
-static unsigned short s_rs1[] = {
+static const unsigned short s_rs1[] = {
    522, 568, 723, 809 };
 
-static unsigned short s_rs2[] = {
+static const unsigned short s_rs2[] = {
    237, 308, 436, 284, 646, 653, 428, 379 };
 
-static unsigned short s_rs3[] = {
+static const unsigned short s_rs3[] = {
    274, 562, 232, 755, 599, 524, 801, 132, 295, 116, 442, 428, 295,  42, 176,  65 };
 
-static unsigned short s_rs4[] = {
+static const unsigned short s_rs4[] = {
    361, 575, 922, 525, 176, 586, 640, 321, 536, 742, 677, 742, 687, 284, 193, 517,
    273, 494, 263, 147, 593, 800, 571, 320, 803, 133, 231, 390, 685, 330,  63, 410 };
 
-static unsigned short s_rs5[] = {
+static const unsigned short s_rs5[] = {
    539, 422,   6,  93, 862, 771, 453, 106, 610, 287, 107, 505, 733, 877, 381, 612,
    723, 476, 462, 172, 430, 609, 858, 822, 543, 376, 511, 400, 672, 762, 283, 184,
    440,  35, 519,  31, 460, 594, 225, 535, 517, 352, 605, 158, 651, 201, 488, 502,
    648, 733, 717,  83, 404,  97, 280, 771, 840, 629,   4, 381, 843, 623, 264, 543 };
 
-static unsigned short s_rs6[] = {
+static const unsigned short s_rs6[] = {
    521, 310, 864, 547, 858, 580, 296, 379,  53, 779, 897, 444, 400, 925, 749, 415,
    822,  93, 217, 208, 928, 244, 583, 620, 246, 148, 447, 631, 292, 908, 490, 704,
    516, 258, 457, 907, 594, 723, 674, 292, 272,  96, 684, 432, 686, 606, 860, 569,
@@ -479,7 +479,7 @@ static unsigned short s_rs6[] = {
    157, 374, 242, 726, 600, 269, 375, 898, 845, 454, 354, 130, 814, 587, 804,  34,
    211, 330, 539, 297, 827, 865,  37, 517, 834, 315, 550,  86, 801,   4, 108, 539 };
 
-static unsigned short s_rs7[] = {
+static const unsigned short s_rs7[] = {
    524, 894,  75, 766, 882, 857,  74, 204,  82, 586, 708, 250, 905, 786, 138, 720,
    858, 194, 311, 913, 275, 190, 375, 850, 438, 733, 194, 280, 201, 280, 828, 757,
    710, 814, 919,  89,  68, 569,  11, 204, 796, 605, 540, 913, 801, 700, 799, 137,
@@ -497,7 +497,7 @@ static unsigned short s_rs7[] = {
    609, 829, 189,  20, 167,  29, 872, 449,  83, 402,  41, 656, 505, 579, 481, 173,
    404, 251, 688,  95, 497, 555, 642, 543, 307, 159, 924, 558, 648,  55, 497,  10 };
 
-static unsigned short s_rs8[] = {
+static const unsigned short s_rs8[] = {
    352,  77, 373, 504,  35, 599, 428, 207, 409, 574, 118, 498, 285, 380, 350, 492,
    197, 265, 920, 155, 914, 299, 229, 643, 294, 871, 306,  88,  87, 193, 352, 781,
    846,  75, 327, 520, 435, 543, 203, 666, 249, 346, 781, 621, 640, 268, 794, 534,
@@ -1180,7 +1180,7 @@ static int _pdf417_encode( const char * szCode, int iLen, int * pCW )
 static void _pdf417_reed_solomon( int * pCW, int iLen, int iLevel )
 {
    int * pEC;
-   unsigned short * coef;
+   const unsigned short * coef;
    int i, j, iM, iECLen;
 
    iECLen = _pdf417_ec_size( iLevel );