...DFX IS AN RSX PROGRAM TO DO ABSOLUTE DISK PATCHES ON
	TO YOUR CURRENT SY: DISK. CALLING SEQUENCE IS VIA A 
	
	MCR>DFX
	
	IN RESPONSE TO "ENTER DISK BLOCK #" TYPE BLOCK NUMBER IN OCTAL
	OR "E" TO EXIT TO RSX. THE BLOCK WILL BE READ IN AND CAN BE
	DISPLAYED BY THE "L" COMMAND. DISPLAY IS ON LUN 6
	
	NOTE THAT LUN 2 IS USED FOR DISK READS AND LUN 4 FOR DISK WRITES,
	AS A PROTECTIVE MEASURE LUN 4 IS ASSIGNED TO PSEUDO DEVICE XX:
	AND MUST BE RE-ASSIGNED BY THE USER BEFORE TO ENABLE WRITE-BACK
	
	ALSO NOT THAT LUN 6 IS USED FOR FULL BLOCK LISTINGS. IT IS INITIALLY
	SET TO TI: BUT CAN BE RE-ASSIGNED TO A DISK, AND WILL BE IN THE USERS
	UIC AS "DFX.DAT"
	
	IN RESPONSE TO "DFX>" PROMPT, TYPE
	 
  	L	TO LIST REFERENCED BLOCK
	W	TO WRITE THE CURRENTLY REFERENCED BLOCK BACK ONTO DISK
	N	TO READ THE NEXT BLOCK
	R	TO REREAD THE CURRENT BLOCK (OVERWRITING CURRENT BUFFER)
	B	TO READ THE PREVIOUS BLOCK
	F	FOR FULL-WORD ADDRESSES (DEFAULTS TO BYTE ADDRESSES)
	H	FOR HALF-WORD (BYTE) ADDRESSES IN BLOCK
	T	TO TYPE OUT THE BLOCK AS ASCII TEXT
	S	TO SET/CLEAR FLAG FOR SPOOLING OUTPUT FILE TO LP
		IF LUN 6 IS A DISK, THE FILE WILL BE SPOOLED ON EXIT OR WHEN
		THE SPOOLING FLAG IS CLEARED BY THE OPERATOR
	K	TO CALCULATE CHECKSUM OF FIRST 255. WORDS OF BLOCK
	E	TO EXIT TO THE MONITOR
	 
	THERE ARE 4 M(ODIFY) TYPE COMMANDS, WHERE 
		M=THE BYTE OFFSET OF THE BUFFER WORD TO BE LISTED/MODIFIED
		NOTE THAT FOR M COMMANDS, M MUST BE EVEN, 0 <= M < 1000
 
	M/000000	CHANGE BUFFER WORD TO THE OCTAL VALUE 000000
	M,LLL		CHANGE BUFFER WORD TO RAD50 VALUE OF "LLL"
	M;AA		CHANGE BUFFER WORD TO ASCII VALUE OF "AA"
	M:		DISPLAY BUFFER WORD IN OCTAL, RAD50 AND ASCII
 
	 
	THERE ARE 4 COMMANDS WHICH ALTER THE ABLSOLUTE BLOCK NUMBER
 
	D,N	TO CHANGE DEFAULT BLOCK NUMBER FOR READ AND WRITE TO N WITH-
		OUT CHANGING THE CONTENTS OF THE BUFFER IN CORE. THIS SHOULD
		PERMIT MOVING DATA FROM ONE BLOCK TO ANOTHER.
	A,N	TO READ AND LIST BLOCK N (N ABSENT IMPLIES NEXT BLOCK)
	C,N	TO READ AND LIST ALL BLOCKS UP TO AND INCLUDING BLOCK N.
	 	(N ABSENT IMPLIES TO END OF DISK.)
	P,N	CHANGES THE HIGH-ORDER BLOCK NUMBER FROM THE DISK.
		NO I/O WILL BE DONE, BUT THE BLOCK NUMBER WILL BE COPIED
		FROM THE HIGH-ORDER AND LOW-ORDER BLOCKS TO RELATIVE
		WORDS 400 & 401 (BYTE OFFSET 1000 & 1002) PAST THE IO BUFFER
		WHERE THE SINGLE-WORD EXAMINING COMMANDS CAN SEE THEM.