Memory pointers
Location | Variable       : Usage/Address
---------|----------------:---------------------------------------------
  ip1    | x(nnp,ndim)    : nodal coordinates  / [ra(ip1)]
  ip2    | f(nnp)         : force/displacement / [ra(ip2)]
  ip3    |                : 
  ip4    | np(nel,nwix)   : connectivity array / [ia(ip4)]
  ip5    | rk(nnp,nbw)    : stiffness matrix   / [ra[ip5)]


 Array : icntl(MXCNTL)
Location | Variable       : Usage
---------|----------------:---------------------------------------------
    1    | nnp            : number of nodal points
    2    | nel            : number of elements
    3    | nmat           : number of materials
    4    | ndim           : dimension of the problem (2 or 3)
    5    | ndof           : number of degrees of freedom per node
    6    | nnpe           : number of nodes per element
    7    | nwix           : size of np connectivity nwix = nnpe + 1
    8    | nelblk         : # of element blocks
    9    | nndset         : # of node sets in the mesh
   10    | nsdset         : # of side sets in the mesh

    ...

   91    | Logical unit number #1  - Input mesh file lun = 5
   92    | Logical unit number #2  - Output File lun = 7
   93    | Logical unit number #3  - Output to screen lun = 6
   94    | Logical unit number #4  - Plot file, lun = 8


Array : rcntl(MXCNTL)
Location | Variable       : Usage
---------|----------------:---------------------------------------------
    1    |                : 
    2    |                : 
    3    |                :