Various logical name definitions are made by the command file sys_specx:specxstart.com, which should be run before attempting to use the program. SPECX contains facilities for getting parameters from the command line -- in order to use these facilities the SPECX command must be installed in the VMS command tables, which is done from within specxstart.com using the DCL command:
$ set command sys_specx:specx
If the command has not been installed at your site by the system manager, then you should arrange that you install it yourself, using the command:
$ @sys_specx:specxstart