These files are the topmodel and example input files.  You can run this two 
different ways.   On Windows computers, just run "top_win.exe" in a command 
window.   To get a command window, do the following <start> - <run> type 
"command" in the <run> dialog.   Then change directory to the place on your 
machine where you unzipped this file.   Then you can run "top_win.exe".  If you 
want/need to compile the code, either use MicroSoft C Developer Studio to 
re-compile, or install "mingw", the gnu C compiler port to Windows.  To compile
with mingw running on Windows or with gcc running on Linux, type:

gcc -g tmod9502.c -o topmod.exe -lm

the -g includes debug information in case you know how to use gdb the gnu debugger
the -o names th executable "topmod.exe", and -lm links in the math library which
is needed for sqrt(), log(), exp(), and pow() operations.

This zip file contains the following files:

inputs.dat   - the example inputs file
params.dat   - the example parameter file
README.1ST   - this file
subcat.dat   - the example subcatchment data file (incl. ln(a/tanB) dist.)
tmod9502.c   - the C source code.  
               the executable will be named topmod.exe.
topmod.run   - the example main driver file.   A file of this name/contents must
               exist.
top_win.exe  - the compiled executable for M.S. Windows.   This will not run in
               Linux.
demo_hydrograph.out - execution output for the C topmodel version for unit testing.

If you have questions about units, look in the source code, or do an on-line 
search.   There is a lot on the www about TOPMODEL.