For those applications which are written in C/2, a 7526 specific, custom CRT0 module is provided within the CFRAPI26.LIB library file. This is the C run-time initialization module which sets up the environment to be consistent with the compiler's code generation assumptions. Under PC-DOS, it provides the standard file streams, access to command line parameters, access to environment variables, and sets up the various segments and registers according to the selected memory model. Most of these services are not available on the 7526, therefore the custom CRT0 module must be substituted for the standard one normally in the C library. The main function of the custom CRT0 module is to establish the segment and register conventions based on the selected memory model. The CRT0 routine for CFRs is imbedded in the CFRAPI26.LIB runtime library and is not explicitly linked.