Int_t vacoord(Int_t vachan) {

  // converts vachannel number to x and y coordinates in logical
  // channel maps

  // cout << "1:  " << xc << ":" << yc << ":" << vachan << endl;
  Int_t xc=0;
  Int_t yc=0;

  switch (vachan) {
  case 0:
    xc=0;
    yc=0;
    break;
  case 1:
    xc=1;
    yc=0;
    break;
  case 2:
    xc=1;
    yc=1;
    break;
  case 3:
    xc=2;
    yc=1;
    break;	    
  case 4:
    xc=3;
    yc=1;
    break;	  
  case 5:
    xc=4;
    yc=1;
    break;
  case 6:
    xc=1;
    yc=2;
    break;
  case 7:
    xc=2;
    yc=2;
    break;
  case 8:
    xc=3;
    yc=2;
    break;
  case 9:
    xc=4;
    yc=2;
    break;
  case 10:
    xc=1;
    yc=3;
    break;
  case 11:
    xc=2;
    yc=3;
    break;
  case 12:
    xc=3;
    yc=3;
    break;
  case 13:
    xc=4;
    yc=3;
    break;
  case 14:
    xc=1;
    yc=4;
    break;
  case 15:
    xc=2;
    yc=4;
    break;
  case 16:
    xc=3;
    yc=4;
    break;
  case 17:
    xc=4;
    yc=4;
    break;
  case 18:
    xc=2;
    yc=5;
    break;
  case 19:
    xc=3;
    yc=5;
    break;
  case 20:
    xc=4;
    yc=5;
    break;
  case 21:
    xc=5;
    yc=5;
    break;
  }
  // cout << "2:  " << xc << ":" << yc << ":" << vachan << endl;

 return xc+yc*6;

}