The physical problem is that of case (100), effected by:
L(101)
    but the amount of memory available is further reduced by
    the command:
NFMAX=-9000
    As a consequence, EARTH automatically switches off the whole-
    field solver, and reverts to the slab-wise one. Consequently,
    many sweeps are needed for convergence, and the computer time
    is increased.
    The next commands allow this, and switches on the graphical
    monitor so that the effects can be observed.
TEXT(3D Heat Cond, Slab-Wise Solver   
TITLE
LSWEEP=2000;TSTSWP=-20;IXMON=3;IYMON=3;IZMON=3
lsweep=200
UWATCH=F;LITER(TEMP)=-LITER(TEMP);OUTPUT(TEMP,Y,Y,Y,Y,Y,Y)