Update (from Aug 1rst, 2008): 
 move all supplementary code to utils/exch2/code-mods
------------------------------------------------------------
Supplementary code mods sets for alternate verification tests
that involve additional code mods. The tests here are designed to check that
cube tilings that have multiple tiles per cube face and that have
missing tiles for all land regions are working OK.

Code mods are in addition to the base mods in code/, i.e. they are applied in genmake2 together
using a command such as
% ../../../tools/genmake2 -mods="../code_alt/code.176t_8x4 ../code"

Directories
code.12t_32x16  :: Same as base but with 12 tiles each of 32x16

code.192t_8x4   :: Same as base but with 192 tiles each of 8x4

code.176t_8x4   :: Same as base but with 176 tiles each of 8x4. This
                :: case has dropped the 8x4 tiles that are
                :: all land in bathy_Hmin50.bin.

The modified "ini_masks_etc.F" in code.192t_8x4/ was used to generate
the list of all land tiles for code.176t_8x4/. This list is used by the
utils/exch2/matlab_topology_generator/driver.m program. The "driver.m"
program reads an optional file "blanklist.txt" that lists tiles that
are blank in the full tile case. The topology files (W2_EXCH2_TOPOLOGY.h 
and w2_e2setup.F) that are generated are then missing thise tiles.