The symbol EPA is defined on the cc command line with -DEPA only on systems which can read EPA files. Currently, only Cray systems can read EPA files because the EPA-provided file reading functions only work on Cray computers.
The symbol MCIDAS is defined on the cc command line with -DMCIDAS only on systems which can use the libmcidas.a file. Only SGI's in 32-bit mode are supported now.