anchor.diff:      FDictionarySize : TAbZipDictionarySize;
       FShannonFanoTreeCount : Byte;
       FOnProgress : TAbProgressEvent;
  -    FOnRequestNthDisk : TAbRequestNthDiskEvent;
       FCurrentProgress : Byte;
  -    {spanning variables}
  -    FSpanned : Boolean;
  -    FArchiveName : string;
  -    FArchive : TAbArchive;
  -    FCurrentDisk : Word;
  -    FMode : Word;
   
       FOutBuf : PAbByteArray;          {output buffer}
       FOutSent : LongInt;              {number of bytes sent to output buffer}
  
positive.code:                                    aDecoder : TObject );
  begin
    inherited Create;
    FOutBuf := AllocMem( AbBufferSize );                                 
    FOutPos := 0;                                                        
    FZStream := InputStream;
    FOutStream := OutputStream;
  
negative.code:     destructor Destroy;
        override;
  
      function Execute : LongInt;
        {returns the CRC}
      property OnProgress : TAbProgressEvent
        read FOnProgress
        write FOnProgress;
      property CompressedSize : LongInt
        read FCompressedSize
        write FCompressedSize;
  