public void calculateChecksum(Patch ip,int start,int end,int ofs)
protected void calculateChecksum(Patch ip,int start,int end,int ofs)
  public void calculateChecksum(Patch ip,int start,int end,int ofs)  {  	Patch p = (Patch)ip;  	int i;    int sum=0;      for (i=start;i<=end;i++)      sum+=p.sysex[i];    p.sysex[ofs]=(byte)(sum % 128);     }