  
  
 		USING FILES FROM A BASIC PROGRAM
  
  
 IMMEDIATE MODE COMMANDS (THESE COMMANDS MAY NOT BE IN PROGRAMS)
  
      LET  f  BE A STANDARD RSX11M FILESPECIFIER
  
 SAVE f		Saves the program in memory to a disk file
 		with a filename  f.  SAVE will not overwrite
 		an existing version number.
  
 REPLACE f	Places the program in memory to a disk file 
 		with a filename f.  REPLACE will overwrite
 		an existing version number.
  
 UNSAVE f	Deletes a disk file with filename f.  The
 		files version number must be
 		specified.
  
 OLD f		Brings a disk file program into
 		memory.  Automatically clears the variable
 		storage area and any old program lines before
 		bringing in the program.
  
 APPEND f	Merges disk filename f with the program already
 		in memory.
  
 RUN[NH] f	OLD's the filename f, and RUNs it.
  
 CAT  [f]	Provides a catalog of those programs under your UIC.
 		if no file specifier is present, lists all files with
 		a .BAS type.  Wild cards allowed, ie to list all files
 		of all types and versions,
  
 				CAT *.*;*
  
 USING PROGRAM FILES (THESE COMMANDS MUST BE IN PROGRAMS)
  
 	LET  s  BE A STRING VARIABLE OR A STRING ENCLOSED IN ""
 	REPRESENTING A STANDARD RSX11M FILESPECIFIER
  
 OPEN s AS FILE expression
 OPEN s FOR INPUT AS FILE expression
 OPEN s FOR OUTPUT AS FILE expression
  
 		Before a file is used it must be OPENED.
 		The  experession must evaluate to an integer
 		from 1-12. Refer to section 6.2.1 of the BASIC
 		Language Reference Manual for an explanation
 		of the implications of INPUT/OUTPUT.
  
 CLOSE expression
  
 		Closes the OPEN file associatd with the
 		integer gigen by  expression.
  
 INPUT #expression, variable1,[variable2,variable3,....]
  
 		expression is the number associated with the 
 		desired file. The variable(s) can be string, integer,
 		floating point, or subscripted variables.
  
 PRINT #expression[,list]
  
 		expression is the number associated with the 
 		desired file.  If lsit is omitted a blank line is 
 		inserted into the file.  The list contains items 
 		to be printed usng the same format as with
 		the PRINT statement.  The list can contain
 		any numeric or strin expressions.
  
 IF END expression THEN statement
 IF END expression THEN line number
 IF END expression GOTO line number
  
 		The IF END statement allows the program to detect
 		if the end of a sequential file has been
 		reached and to transfer control to some other
 		line number when this occurs. expression is  
 		the number of the file.
  
 DIM #integer1, array[=integer2]
  
 		VIRTUAL ARRAYS can be used just like a normal
 		array except that before using one an OPEN
 		statement and a DIM # statement must be execuited.
 		PRINT #, and INPUT # statements are not used with
 		VIRTUAL ARRAYS.  integer1 is the constant number
 		associated with the file.  The array is a 1 or 2
 		dimensioned array with the same format as in the
 		DIM statement.  integer2 is a constant that specifies
 		the maximum length of a string array
 		(1-256).  If omitted it defaults to 16.
  
  
 NAME string1 TO string2
  
 		Changes the name of a file with a file name
 		given by string1 to a filename given by string2.
  
 KILL s
  
 		KILL deletes the file given by the filespecifier
 		s.
  
