public MemoryMapper(String outputdir,String filename){
        int i;
        //memc=new byte[65536];
        memnc=new int[65536];
        for(i=0;i<65536;i++){
          //  memc[i]=0;
            memnc[i]=0;
        }
        dumpFile=new File(outputdir,filename+".mmap");
        
        
    }