
A SDDS-compliant C-interface was written for the EGS4 code.  The
EGS4 code is a set of subroutines that generates and tracks
particle in a electromagnetic shower.  In the conventional EGS4
code system, the user must supply their own input and output
routines and problem geometry definition written in the MORTRAN
language.  This arduous process has been replaced by reading and
writing input and output particle information as data files, the
geometry definition as a file of namelist type commands, and other
information in an addition summary data file.  All data files are
in SDDS format, and therefore compatible with other processing and
tracking programs.

Presently the geometry definition for a given run is limited to 
3D rectangular prisms or cylinders along the z axis. The
shapes can be nested to create complex geometries.

