diff --git a/NgeReader.cpp b/NgeReader.cpp
index b76c4d3..9a4eadf 100644
--- a/NgeReader.cpp
+++ b/NgeReader.cpp
@@ -17,6 +17,8 @@
 #include "NgeKeyW.h"
 #include "/EgtDev/Include/EGkStringUtils3d.h"
 #include "/EgtDev/Include/EgtStringConverter.h"
+#include "/EgtDev/Extern/zlib/Include/zlib.h"
+#include <fstream>
 
 using namespace std ;
 
@@ -34,8 +36,12 @@ NgeReader::Init( const string& sFileIn)
       break ;
    case NGE_BINARY :
       m_bBinary = true ;
-      m_InFile.open( stringtoW( sFileIn), ios::in | ios::binary, _SH_DENYWR) ;
-      return ( ! m_InFile.fail()) ;
+      m_InFile = gzopen_w( stringtoW( sFileIn), "rb") ;
+      if ( m_InFile == nullptr)
+         return false ;
+      const int DIM_BUFFER = 65536 ;
+      gzbuffer( m_InFile, DIM_BUFFER) ;
+      return true ;
       break ;
    }
    return false ;
@@ -46,10 +52,12 @@ bool
 NgeReader::Close( void) 
 {
    if ( m_bBinary) {
-      bool bOk = ( m_InFile.good()  &&  m_InFile.is_open()) ;
-      if ( m_InFile.is_open())
-         m_InFile.close() ;
-      return bOk ;
+      if ( m_InFile != nullptr) {
+         bool bOk = ( gzclose( m_InFile) == Z_OK) ;
+         m_InFile = nullptr ;
+         return bOk ;
+      }
+      return true ;
    }
    else
       return m_Scan.Terminate() ;
@@ -91,7 +99,7 @@ int
 NgeReader::GetCurrPos( void)
 {
    if ( m_bBinary)
-      return int( m_InFile.tellg()) ;
+      return int( gztell( m_InFile)) ;
    else
       return m_Scan.GetCurrLineNbr() ;
 }
@@ -131,10 +139,9 @@ bool
 NgeReader::ReadUchar( unsigned char& ucVal, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &ucVal, sizeof( ucVal)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &ucVal, sizeof( ucVal)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -154,10 +161,9 @@ bool
 NgeReader::ReadBool( bool& bVal, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &bVal, sizeof( bVal)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &bVal, sizeof( bVal)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -173,10 +179,9 @@ bool
 NgeReader::ReadInt( int& nVal, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &nVal, sizeof( nVal)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &nVal, sizeof( nVal)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -203,10 +208,9 @@ bool
 NgeReader::ReadDouble( double& dVal, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &dVal, sizeof( dVal)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &dVal, sizeof( dVal)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -222,10 +226,9 @@ bool
 NgeReader::ReadVector( Vector3d& vtV, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &vtV.v, sizeof( vtV.v)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &vtV.v, sizeof( vtV.v)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -241,10 +244,9 @@ bool
 NgeReader::ReadPoint( Point3d& ptP, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &ptP.v, sizeof( ptP.v)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &ptP.v, sizeof( ptP.v)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -260,11 +262,10 @@ bool
 NgeReader::ReadPointW( Point3d& ptP, double& dW, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      m_InFile.read( (char*) &ptP.v, sizeof( ptP.v)) ;
-      m_InFile.read( (char*) &dW, sizeof( dW)) ;
-      return m_InFile.good() ;
+      return ( gzread( m_InFile, &ptP.v, sizeof( ptP.v)) != Z_ERRNO  &&
+               gzread( m_InFile, &dW, sizeof( dW)) != Z_ERRNO) ;
    }
    else {
      // recupero il token
@@ -280,17 +281,13 @@ bool
 NgeReader::ReadFrame( Frame3d& frF, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
-      Point3d ptOrig ;
-      m_InFile.read( (char*) &ptOrig.v, sizeof( ptOrig.v)) ;
-      Vector3d vtDirX ;
-      m_InFile.read( (char*) &vtDirX.v, sizeof( vtDirX.v)) ;
-      Vector3d vtDirY ;
-      m_InFile.read( (char*) &vtDirY.v, sizeof( vtDirY.v)) ;
-      Vector3d vtDirZ ;
-      m_InFile.read( (char*) &vtDirZ.v, sizeof( vtDirZ.v)) ;
-      if ( ! m_InFile.good())
+      Point3d ptOrig ; Vector3d vtDirX, vtDirY, vtDirZ ;
+      if ( gzread( m_InFile, &ptOrig.v, sizeof( ptOrig.v)) == Z_ERRNO  ||
+           gzread( m_InFile, &vtDirX.v, sizeof( vtDirX.v)) == Z_ERRNO  ||
+           gzread( m_InFile, &vtDirY.v, sizeof( vtDirY.v)) == Z_ERRNO  ||
+           gzread( m_InFile, &vtDirZ.v, sizeof( vtDirZ.v)) == Z_ERRNO)
          return false ;
       return frF.Set( ptOrig, vtDirX, vtDirY, vtDirZ) ;
    }
@@ -308,18 +305,20 @@ bool
 NgeReader::ReadString( string& sVal, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
+      if ( m_InFile == nullptr)
+         return false ;
       const int MAX_STR_DIM = 65535 ;
-      if ( ! m_InFile.is_open())
-         return false ;
       int nDim ;
-      m_InFile.read( (char*) &nDim, sizeof( nDim)) ;
-      if ( nDim > MAX_STR_DIM  ||  ! m_InFile.good())
+      if ( gzread( m_InFile, &nDim, sizeof( nDim)) == Z_ERRNO  ||  nDim > MAX_STR_DIM)
          return false ;
+      if ( nDim == 0) {
+         sVal = "" ;
+         return true ;
+      }
       char* szBuff = new( nothrow) char[ nDim + 1] ;
       if ( szBuff == nullptr)
          return false ;
-      m_InFile.read( szBuff, nDim) ;
-      if ( ! m_InFile.good()) {
+      if ( gzread( m_InFile, szBuff, nDim) == Z_ERRNO) {
          delete[] szBuff ;
          return false ;
       }
@@ -348,12 +347,11 @@ NgeReader::ReadKey( int& nKey)
       return true ;
    }
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
      // leggo il dato
       int nVal ;
-      m_InFile.read( (char*) &nVal, sizeof( nVal)) ;
-      if ( ! m_InFile.good())
+      if ( gzread( m_InFile, &nVal, sizeof( nVal)) == Z_ERRNO)
          return false ;
      // ricavo l'indice
       for ( int i = 0 ; i <= NGE_LAST_ID ; ++ i) {
@@ -386,11 +384,10 @@ bool
 NgeReader::ReadCol( Color& cCol, const char* szSep, bool bEndL)
 {
    if ( m_bBinary) {
-      if ( ! m_InFile.is_open())
+      if ( m_InFile == nullptr)
          return false ;
       unsigned char ucCol[4] ;
-      m_InFile.read( (char*) &ucCol, sizeof( ucCol)) ;
-      if ( ! m_InFile.good())
+      if ( gzread( m_InFile, &ucCol, sizeof( ucCol)) == Z_ERRNO)
          return false ;
       cCol.Set( ucCol[0], ucCol[1], ucCol[2], ucCol[3]) ;
       return true ;
diff --git a/NgeReader.h b/NgeReader.h
index 7f39b98..0df0e9a 100644
--- a/NgeReader.h
+++ b/NgeReader.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
-//  EgalTech 2014-2014
+//  EgalTech 2014-2025
 //----------------------------------------------------------------------------
-// File : NgeReader.h          Data : 14.04.14           Versione : 1.5d5
+// File : NgeReader.h          Data : 29.12.25           Versione : 2.7l6
 // Contenuto : Dichiarazione della classe NgeReader.
 //
 //
@@ -18,14 +18,16 @@
 #include "/EgtDev/Include/EGkColor.h"
 #include "/EgtDev/Include/EGnScanner.h"
 #include "/EgtDev/Include/EgtStringBase.h"
-#include <fstream>
+
+struct gzFile_s ;
 
 //----------------------------------------------------------------------------
 class NgeReader
 {
    public :
       NgeReader( void)
-            : m_iPosStart( std::string::npos), m_bUngetKey( false), m_nFileVer() {}
+            : m_bBinary( false), m_InFile( nullptr), m_iPosStart( std::string::npos),
+              m_bUngetKey( false), m_nLastKey(), m_nFileVer() {}
       ~NgeReader( void)
             { Close() ; }
       bool Init( const std::string& sFileIn) ;
@@ -60,7 +62,7 @@ class NgeReader
    private :
       bool                   m_bBinary ;
       // per file binari
-      std::ifstream          m_InFile ;
+      gzFile_s*              m_InFile ;
       // per file ASCII
       Scanner                m_Scan ;
       std::string::size_type m_iPosStart ;
diff --git a/NgeWriter.cpp b/NgeWriter.cpp
index 1328353..31a8ce7 100644
--- a/NgeWriter.cpp
+++ b/NgeWriter.cpp
@@ -90,7 +90,7 @@ NgeWriter::WriteUchar( unsigned char ucVal, const char* szSep, bool bEndL)
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &ucVal, sizeof( ucVal)) > 0) ;
+      return ( gzwrite( m_OutFile, &ucVal, sizeof( ucVal)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( ucVal).c_str(), szSep, bEndL) ;
@@ -104,7 +104,7 @@ NgeWriter::WriteBool( bool bVal, const char* szSep, bool bEndL)
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &bVal, sizeof( bVal)) > 0) ;
+      return ( gzwrite( m_OutFile, &bVal, sizeof( bVal)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( bVal).c_str(), szSep, bEndL) ;
@@ -118,7 +118,7 @@ NgeWriter::WriteInt( int nVal, const char* szSep, bool bEndL)
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &nVal, sizeof( nVal)) > 0) ;
+      return ( gzwrite( m_OutFile, &nVal, sizeof( nVal)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( nVal).c_str(), szSep, bEndL) ;
@@ -132,7 +132,7 @@ NgeWriter::WriteDouble( double dVal, const char* szSep, bool bEndL, int nPrec)
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &dVal, sizeof( dVal)) > 0) ;     
+      return ( gzwrite( m_OutFile, &dVal, sizeof( dVal)) > 0) ;     
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( dVal, nPrec).c_str(), szSep, bEndL) ;
@@ -147,7 +147,7 @@ NgeWriter::WriteString( const string& sVal, const char* szSep, bool bEndL)
       if ( m_OutFile == nullptr)
          return false ;
       int nDim = ssize( sVal) ;
-      return ( gzwrite( m_OutFile, (char*) &nDim, sizeof( nDim)) > 0  &&
+      return ( gzwrite( m_OutFile, &nDim, sizeof( nDim)) > 0  &&
                ( nDim == 0  ||  gzwrite( m_OutFile, sVal.c_str(), sVal.size()) > 0)) ;
    }
    else {
@@ -162,7 +162,7 @@ NgeWriter::WriteVector( const Vector3d& vtV, const char* szSep, bool bEndL, int
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &vtV.v, sizeof( vtV.v)) > 0) ;
+      return ( gzwrite( m_OutFile, &vtV.v, sizeof( vtV.v)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( vtV, nPrec).c_str(), szSep, bEndL) ;
@@ -176,7 +176,7 @@ NgeWriter::WritePoint( const Point3d& ptP, const char* szSep, bool bEndL, int nP
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &ptP.v, sizeof( ptP.v)) > 0) ;
+      return ( gzwrite( m_OutFile, &ptP.v, sizeof( ptP.v)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( ptP, nPrec).c_str(), szSep, bEndL) ;
@@ -190,8 +190,8 @@ NgeWriter::WritePointW( const Point3d& ptP, double dW, const char* szSep, bool b
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &ptP.v, sizeof( ptP.v)) > 0  &&
-               gzwrite( m_OutFile, (char*) &dW, sizeof( dW)) > 0) ;
+      return ( gzwrite( m_OutFile, &ptP.v, sizeof( ptP.v)) > 0  &&
+               gzwrite( m_OutFile, &dW, sizeof( dW)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( ptP, dW, nPrecP, nPrecW).c_str(), szSep, bEndL) ;
@@ -205,10 +205,10 @@ NgeWriter::WriteFrame( const Frame3d& frF, const char* szSep, bool bEndL, int nP
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &frF.Orig().v, sizeof( frF.Orig().v)) > 0  &&
-               gzwrite( m_OutFile, (char*) &frF.VersX().v, sizeof( frF.VersX().v)) > 0  &&
-               gzwrite( m_OutFile, (char*) &frF.VersY().v, sizeof( frF.VersY().v)) > 0  &&
-               gzwrite( m_OutFile, (char*) &frF.VersZ().v, sizeof( frF.VersZ().v)) > 0) ;
+      return ( gzwrite( m_OutFile, &frF.Orig().v, sizeof( frF.Orig().v)) > 0  &&
+               gzwrite( m_OutFile, &frF.VersX().v, sizeof( frF.VersX().v)) > 0  &&
+               gzwrite( m_OutFile, &frF.VersY().v, sizeof( frF.VersY().v)) > 0  &&
+               gzwrite( m_OutFile, &frF.VersZ().v, sizeof( frF.VersZ().v)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( frF, nPrecP, nPrecV).c_str(), szSep, bEndL) ;
@@ -225,7 +225,7 @@ NgeWriter::WriteKey( int nKey)
    if ( m_bBinary) {
       if ( m_OutFile == nullptr)
          return false ;
-      return ( gzwrite( m_OutFile, (char*) &NgeBinKeyW[nKey], sizeof( int)) > 0) ;
+      return ( gzwrite( m_OutFile, &NgeBinKeyW[nKey], sizeof( int)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, NgeAscKeyW[nKey].c_str(), nullptr, true) ;
@@ -244,7 +244,7 @@ NgeWriter::WriteCol( const Color& cCol, const char* szSep, bool bEndL)
       ucCol[1] = cCol.GetIntGreen() ;
       ucCol[2] = cCol.GetIntBlue() ;
       ucCol[3] = cCol.GetIntAlpha() ;
-      return ( gzwrite( m_OutFile, (char*) ucCol, sizeof( ucCol)) > 0) ;
+      return ( gzwrite( m_OutFile, ucCol, sizeof( ucCol)) > 0) ;
    }
    else {
       return WriteStringOutTxt( m_OutFile, ToString( cCol).c_str(), szSep, bEndL) ;
diff --git a/NgeWriter.h b/NgeWriter.h
index 63b0139..ae2b95a 100644
--- a/NgeWriter.h
+++ b/NgeWriter.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
-//  EgalTech 2014-2014
+//  EgalTech 2014-2025
 //----------------------------------------------------------------------------
-// File : NgeWriter.h          Data : 12.04.14           Versione : 1.5d5
+// File : NgeWriter.h          Data : 29.12.25           Versione : 2.7l6
 // Contenuto : Dichiarazione della classe NgeWriter.
 //
 //