in MPE/V you could check it with the CIEROR: UDCXX FILE SETJCW CIERROR,0 CONTINUE LISTF !FILE;$NULL IF CIERROR = 0 THEN ... file exists ELSE ... file does not exist ENDIF in MPE/iX it is easier with a command file: PARM FILE IF FINFO("!FILE",0) THEN ... file exists ELSE ... file does not exist ENDIF