home *** CD-ROM | disk | FTP | other *** search
- SIG/M VOLUME 5
-
- 8080/8085, MEMORY, ICOM DISK CONTROLLER DIAGNOSTICS
-
- SIZE NAME COMMENTS
-
- -CATALOG.005 CONTENTS OF SIG/M VOL. 5
-
- 5.1 14K CPUDIAG.ASM CPU TEST DIAGNOSTICS FOR 8080 AND 8085
- 5.2 2K CPUDIAG.DOC CPU TEST DIAGNOSTICS FOR 8080 AND 8085
- 5.3 12K MEMDIAG.DOC MEMORY DIAGNOSTICS
- 5.4 34K MEMDIAG.ASM MEMORY DIAGNOSTICS
- 5.5 73K 3712DIAG.ASM ICOM SINGLE DENSITY DISK CONTROLLER DIAGNOSTIC
- 5.6 93K 3812DIAG.ASM ICOM DOUBLE DENSITY DISK CONTROLLER DIAGNOSTIC
- 5.7 2K 3X12DIAG.DOC ICOM DISK CONTROLLER DIAGNOSTICS
- 5.8 4K CP/M-NET.MSG PROPOSED NETWORKING OF USER GROUPS
-
-
- To Bruce Ratoff, Tom Churbuck, Keith Petersen
-
-
- Proposal For A Collaborate National CP/M User's Group
-
- June 26, 1980
-
- I would like to propose a merging of the "SIG/M" CP/M User's
- Group now in it's formative stages with "CP/M-NET (tm)", for
- the purpose of public access (via modem) dissemination of CP/M
- compatble public domain software. Benefits to be derived to the
- "programming public at large" are:
-
- 1.0 Free access to "professional quality" software for the
- price of a telephone call.
-
- 2.0 A "try before you buy" access of "commercial software"
-
- 3.0 Software "critique's" of "commercial software"
-
- 4.0 "language access" availability as a tutorial aid to a
- better understanding of various languages (BASIC, FORTRAN,
- COBOL, PASCAL/UCSD, PASCAL/M, PASCAL/MT, PASCAL/Z, "C",
- etc.).
-
- 5.0 A program "forwarding" network for "mass dissemination" of
- software.
-
- 6.0 An "on going" dialogue of "here's how to do it"
- documentation, for implementation of software (e.g., how
- to get MP/M running on your system...,etc.). Believe me,
- alot of people out there are "baffled" at how to write a
- BIOS, or how to change I/O for various systems, etc.!
-
-
- These are just a view of my thoughts that have come to mind on
- this issue, and I am sure that you could add quite a bit to
- this...
-
- The time and ability is certainly "at hand", by evidence of
- Keith Petersen's system, Tom Churbuck's System, the Valley
- Computer Club system, my system, and other's...If we could
- standardize access methods, utility formats, etc., as
- "affiliate systems", we could offer quite a bit to the public
- "education" of the utilization of computers.
-
- I would be more than willing to be the "West Coast" affiliate
- system, and help in all details of this proposed project.
-
- Additionally, we might publish a quarterly "news letter",
- requiring possibly a $12 per year membership fee to cover
- expenses of system operation and maintenance. Of primary
- interest to me, is to make public domain software PUBLIC! Not
- under the control of profit making organization such as èLifeboat (read Tony Gold here...) that (in general) have little
- professional software to offer in their control of the
- CPMUG/Lifelines "racket", much less some of the really "crap"
- commercial software like "BSTAM"! (WOW, did I say that?!?).
-
- Also, I suspect that if "SIG/M" really gets "rolling", you
- will have your hands full with the logistics of distributing
- "physical diskettes" to the public...my proposal would
- certainly take care of any problems in that area.
-
- To conclude, give this some thought as what we "collectively"
- might do...leave any correspondence on this matter on my system
- or Tom Churbuck's system as an "open forum".
-
- Best Regards,
-
- Kelly Smith, CP/M-NET (tm)
- 3055 Waco Avenue
- Simi Valley, California, 93065
- (805) 527-9321 (300 Baud Modem)
- (805) 527-0518 (Verbal)
-
-
-
-
- Microcosm Associates Disk Diagnostic
-
- for the
-
- Icom FD3712 Single Density Disk Controller
-
- and the
-
- Icom FD3812 Double Density Disk Controller
-
-
- Donated to the "SIG/M" CP/M User's Group by Kelly Smith
-
-
- This is an extensive "production test/diagnostic" for the
- Pertec/Icom Single and Double Density Disk Controller. The
- files 3712DIAG.ASM and 3812DIAG.ASM are "self documenting",
- with a "menu display" of test options at the first execution of
- either program. These programs were originaly written for the
- MITS Altair 8800b Computer, and therefor utilize the MITS
- console port address's of 10 and 11 hexadecimal. These
- address's may easily be modified by changing the console
- equates as required by you console I/O. In addition, the
- 3712DIAG.ASM file is compatible for testing the older Icom
- "Frugal Floppy" system.
-
- Primary differences between the FD3712 and FD3812 diagnostics
- are in "density select" options and diskette formating
- capabilities of the 3812DIAG.ASM file, which supports the IBM
- single density/single sided format, "1D" format, "2D" format,
- and "2D Extended (1024 bytes per sector, 8 sectors per track)
- format ("2D Extended" is hardware dependent on DMA transfer
- capability).
-
- This code was initially written by me about 3 years ago, when
- I first got into codeing for the 8080, and is therefor a bit
- "amateurish" in some areas...that "INIT" routine with all the
- "STA's" for example! But in any case, the code does work quite
- well for a first effort on my part...
-
-
- Kelly Smith, Microcosm Associates
- 3055 Waco Avenue
- Simi Valley, California
- (805) 527-9321 (Modem, CP/M-NET)
- (805) 527-0518 (Verbal)
-
- ***************************************************************
- OPERATORS MANUAL FOR THE MICROCOSM ASSOCIATES
- MEMORY DIAGNOSTIC, VERSION 1.0
- ***************************************************************
-
- COPYRIGHT 1979,1980 BY MICROCOSM ASSOCIATES
-
- DONATED TO THE "SIG/M" CP/M USER'S GROUP, BY KELLY SMITH
-
- CP/M IS A REGISTERED TRADEMARK OF DIGITAL RESEARCH
-
-
- 1.0
-
- DIAGNOSTIC TEST "START-UP" EXECUTION
-
- 1.1
-
- THE TEST WILL INITIALLY "SIGN ON",WITH THE FOLLOWING MESSAGE
- DISPLAYED ON THE REMOTE CONSOLE:
-
-
- MICROCOSM ASSOCIATES MEMORY DIAGNOSTIC VER.1.0 (C) 1979
- TOP OF MEMORY=NNNN
-
- MEMORY QUALIFICATION TEST IS IN PROGRESS
-
-
- ANY ERRORS OCCURING DURING THE "MEMORY QUALIFICATION TEST" WILL
- BE DISPLAYED AS FOLLOWS:
-
-
- ERROR AT ADDRESS=NNNN PATTERN STORED=NN PATTERN READ=NN
- BIT(S) IN ERROR=N,N,N,N,N,N,N,N
-
- THE DIAGNOSTIC PROGRAM WILL NOW PROCEED TO DISPLAY THE
- FOLLOWING MESSAGE ON THE REMOTE SYSTEM CONSOLE:
-
-
- MEMORY TEST IN AUTO MODE (Y OR N)?
-
-
- (REFERENCE SECTION 2.1 C FOR ADDITIONAL INFORMATION)
-
- 2.0
-
- DIAGNOSTIC COMMAND MONITOR
-
- 2.1
-
- WHEN THE "-" PROMPT CHARACTER IS DISPLAYED, THE FOLLOWING
- KEYBOARD ENTRIES MAY BE MADE FOR TEST/DIAGNOSTIC SELECTIONS.
-
- A. "G" CAUSES "GO ADDRESS=", ALLOWING EXECUTION OF CODE AT ANY
- ADDRESS IN ROM/RAM MEMORY.
-
- B. "M" CAUSES "MEMORY ADDRESS ", TO ALLOW DISPLAYING ANY ADDRESS
- IN ROM/RAM MEMORY. FOR EXAMPLE:
-
- -MEMORY ADDRESS=NNNN (CR)
- NNNN=NN (SP)
- NNN1=NN AA (WHERE "AA" IS AN OPERATOR ENTRY)
- NNN2=NN ^ (WHERE "^" IS AN OPERATOR ENTRY TO EXAMINE
- "PREVIOUS")
- NNN1=AA (SP)
- NNN2=BB E (WHERE "E" INDICATES "MEMORY ERROR" ON ENTRY)
- NNN3=NN (CR)
- - (WHERE "-" IS A RETURN TO THE MONITOR BY
- CARRIAGE-RETURN)
-
- C. "T" CAUSES "TEST MEMORY IN AUTO MODE (Y OR N)?" TO BE
- DISPLAYED ON THE REMOTE CONSOLE.ENTERING "Y" ON THE REMOTE
- CONSOLE KEYBOARD WILL CAUSE THE FOLLOWING DISPLAY TO APPEAR:
-
- NO MEMORY BLOCKS DROPPED
-
- TESTING MEMORY FROM 1000 TO 2000
- PASS=0000 TOTAL ERRORS=0000
- RANDOM PATTERNS TEST
-
-
- THE TEST WILL PROCEED TO TEST WITH "WRITE SATURATION TEST",
- "GALLOPING PATTERNS TEST","STATIC CHECK CYCLE","CHECKING DATA
- RETENTION","GALLOPING COLUMNS TEST", AND "WALKING PATTERNS
- TEST". THE TEST WILL THEN PROCEED TO THE NEXT 4K BYTE MEMORY
- BLOCK.
-
- A "N" RESPONSE TO "TEST MEMORY IN AUTO MODE (Y OR N)?" WILL
- CAUSE THE FOLLOWING DISPLAY TO APPEAR ON THE REMOTE CONSOLE:
-
- TEST "ALL","SELECT",OR "MONITOR" (A,S OR M)?
-
- ENTRY OF "S" ON THE KEYBOARD ALLOWS "SELECTION" OF TESTING
- MEMORY FROM ADDRESS 1000 HEX TO FFFF HEX,WITH THE FOLLOWING
- DISPLAY APPEARING ON THE REMOTE CONSOLE: (NOTE: A MINIMUM
- ADDRESS DIFFERENTIAL OF THREE ADDRESS'S MUST BE UTILIZED BY THE
- OPERATOR, AND MEMORY MAY NOT BE TESTED BELOW RAM MEMORY ADDRESS
- 1000 HEX.
-
- LOW MEMORY ADDRESS=NNNN (CR)
- HIGH MEMORY ADDRESS=NNNN (CR)
-
- TEST OPTIONS ARE:
-
- 01-GALLOPING PATTERNS TEST
- 02-GALLOPING COLUMNS TEST
- 03-WALKING PATTERNS TEST
- 04-RANDOM PATTERNS TEST
- 05-WRITE STAURATION TEST
- 06-STATIC CHECK CYCLE TEST
-
- ENTER TEST NUMBER(01,02,03,04,05 OR 06)=NN
- ENTER PATTERN (00-FF)=NN TEST IS IN PROGRESS
-
-
- PROGRAM TEST EXECUTION BEGINS AT THE TWO DIGIT ENTRY FOR "ENTER
- PATTERN (00-FF)=" BY DISPLAYING "TEST IS IN PROGRESS". ENTERING
- "A" FOR "ALL",AUTOMATICALLY BEGINS EXECUTION BY DISPLAYING "TEST
- OPTIONS ARE:",ASSUMING THAT THE TEST ADDRESS RANGE IS FROM 8000
- HEX TO BFFF HEX.
-
- ENTERING "M" FOR "MONITOR",CAUSES EXITING TO THE COMMAND
- MONITOR (SEE SECTION 1.1 FOR DETAILED EXPLANATION OF
- OPERATION),AND WILL PROMPT WITH A "-" CHARACTER TO INDICATE
- MONITOR MODE.
-
- 3.0
-
- RAM MEMORY TEST ERROR MESSAGES
-
- A. RANDOM PATTERNS MEMORY TEST
-
- MEMORY ERRORS OCCURING DURING THE RANDOM PATTERNS TEST WILL BE
- DISPLAYED ON THE REMOTE CONSOLE AS FOLLOWS:
-
-
- ERROR AT ADDRESS=NNNNN PATTERN STORED=NN PATTERN READ=NN
- BIT(S) IN ERROR=N,N,N,N,N,N,N,N
-
-
- NOTE, THAT ON TRANSIENT/DYNAMIC TYPE ERRORS, THE PATTERN STORED
- MAY MATCH THE PATTERN READ AND NO BITS WILL BE IN ERROR. THE
- ERROR DETECTION LOGIC OF THE TEST SOFTWARE IS SUCH THAT ANY
- IMMEDIATE MISMATCH IS DETECTED BUT THE ERROR CELL STATE IS NOT
- SAVED. SUBSEQUENT SOFTWARE PROGRAM DELAYS LATER, THE ERROR CELL
- ADDRESS CONTENT IS AGAIN EXAMINED FOR THE MISMATCH TO BE
- DISPLAYED, BUT THE CELL IS NOW CORRECT. THIS INDICATES THAT A
- TRANSIENT/DYNAMIC ERROR HAS OCCURRED. THE TEST SEQUENCE IS AS
- FOLLOWS:
-
- 1. RANDOM DATA PATTERNS ARE WRITTEN THRUOUT THE 4K BYTE CELL
- MEMORY BLOCK.
-
- 2. ALL 4K BYTE CELLS ARE READ.
-
- 3. ALL 4K BYTE CELLS ARE COMPLEMENTED.
-
- 4. ALL 4K BYTE CELLS ARE READ.
-
- 5. ALL 4K BYTE CELLS ARE ALTERNATELY WRITTEN WITH 55 HEX AND AA
- HEX.
-
- 6. ALL 4K BYTE CELLS ARE READ.
-
- 7. ALL 4K BYTE CELLS ARE COMPLEMENTED.
-
- 8. ALL 4K BYTE CELLS ARE READ.
-
- 9. ALL 4K BYTE CELLS ARE WRITTEN WITH ALL 1'S.
-
- 10. ALL 4K BYTE CELLS ARE READ.
-
- 11. ALL 4K BYTE CELLS ARE COMPLEMENTED.
-
- 12. ALL 4K BYTE CELLS ARE READ.
-
-
- B. WRITE SATURATION TEST
-
- MEMORY ERRORS OCCURING DURING THE WRITE SATURATION TEST WILL BE
- DISPLAYED ON THE REMOTE CONSOLE AS FOLLOWS:
-
-
- ERROR AT ADDRESS=NNNN READ BACK NN ,EXPECTED NN
-
-
- THE FAILURE TYPE REVEALED IS SLOW SENSE AMPLIFIER RECOVERY DUE
- TO SUSTAINED "CHARGING" OF 0'S OR 1'S ON THE SENSE AMPLIFIER
- CIRCUITRY.
-
- THE TEST SEQUENCE IS AS FOLLOWS:
-
- 1. WRITE A "BACKGROUND" PATTERN OF ALL 0'S IN A 4K BYTE BLOCK
- REPEATEDLY FOR 100 WRITE PASSES
-
- 2. WRITE ALL 1'S IN A 4K BYTE BLOCK FOR 1 WRITE PASS ONLY.
-
- 3. SEQUENTIALLY READ ALL BYTES IN THE 4K BYTE BLOCK.
-
- 4. WRITE A "BACKGROUND" PATTERN OF ALL 1'S IN A 4K BYTE BLOCK
- REPEATEDLY FOR 100 WRITE PASSES.
-
- 5. WRITE ALL 0'S IN A 4K BYTE BLOCK FOR 1 WRITE PASS ONLY.
-
- 6. SEQUENTIALLY READ ALL 4K BYTES IN THE 4K BYTE BLOCK.
-
-
- C. GALLOPING PATTERNS MEMORY TEST
-
- MEMORY ERRORS OCCURING DURING THE GALLOPING PATTERNS MEMORY
- WILL BE DISPLAYED ON THE REMOTE CONSOLE AS FOLLOWS:
-
-
- ERROR READING OTHER CELL
- TEST CELL=NNNN, OTHER CELL=NNNN
- PATTERN STORED=NN PATTERN READ=NN
-
-
- THE "OTHER" CELL (WRITTEN FROM A BACKGROUND PATTERN OF 0'S OR
- 1'S) HAS BEEN DISTRUBED BY WRITING INTO THE "TEST" CELL.
-
- ALTERNATELY,THIS MESSAGE MAY APPEAR:
-
-
- ERROR READING TEST CELL
- TEST CELL=NNNN, OTHER CELL=NNNN,
- PATTERN STORED=NN PATTERN READ =NN
-
- THE TEST CELL HAS BEEN DISTURBED BY WRITING INTO SOME "OTHER"
- CELL. THE FAILURE TYPE REVEALED IN EITHER ERROR MESSAGE
- INDICATES EITHER UNSATISFACTORY ADDRESS TRANSITIONS BETWEEN EACH
- CELL AND EVERY OTHER CELL, SLOW SENSE AMPLIFIER RECOVER, OR
- DESTRUCTION OF DATA DUE TO NOISE COUPLING BETWEEN CELLS WITHIN A
- COLUMN. THE TEST SEQUENCE IS AS FOLLOWS:
-
- 1. A "BACKGROUND" PATTERN OF ALL 1'S IS WRITTEN INTO A 256 BYTE
- PORTION OF A 4K BYTE BLOCK OF MEMORY.
-
- 2. THE COMPLIMENT OF THE TEST CELL IS WRITTEN INTO THE TEST
- CELL, AND ALTERNATELY THE TEST CELL IS READ AND EVERY OTHER
- CELL.
-
- 3. THE TEST CELL IS WRITTEN TO IT'S ORIGINAL STATE.
-
- 4. THE NEXT SEQUENTIAL CELL IS TESTED AS IN STEP 2 AND 3.
-
- 5. A "BACKGROUND" PATTERN OF ALL 0'S IS WRITTEN INTO THE SAME
- 256 BYTE PORTION OF THE 4K BYTE BLOCK OF MEMORY.
-
- 6. STEPS 2,3, AND 4 ARE REPEATED.
-
- 7. STEPS 1 THRU 6 ARE REPEATED FOR THE NEXT SEQUENTIAL 256
- BYTES IN THE 4K BYTE BLOCK.
-
-
- D. STATIC CHECK CYCLE.
-
- UTILIZED IN THE MEMORY TEST AUTOMATIC MODE ONLY, A STATIC CHECK
- CYCLE WILL OCCUR AS FOLLOWS:
-
- ANY FURTHER MEMORY READ OR WRITE OPERATION IS TERMINATED FOR
- ONE MINUTE. AFTER THIS DELAY TIME, THE LAST STATE OF MEMORY
- TESTING PATTERNS FROM THE GALLOPING PATTERNS MEMORY TEST IS READ
- FOR THE 4K BYTE BLOCK TO TEST FOR POSSIBLE ERRORS DUE TO
- RETENTION LOSSES. THE FOLLOWING MESSAGE WILL APPEAR ON THE
- REMOTE CONSOLE:
-
-
- CHECKING DATA RETENTION
-
-
- ANY DATA RETENTION ERROR DETECTED WILL BE DISPLAYED ON THE
- REMOTE CONSOLE AS FOLLOWS:
-
-
- DATA RETENTION ERROR AT ADDRESS=NNNN
- EXPECTED "00" DATA, READ BACK NN
-
-
- E. GALLOPING COLUMNS MEMORY TEST
-
- ERROR MESSAGES ARE IDENTICAL TO THOSE DISPLAYED FOR THE
- GALLOPING PATTERNS MEMORY TEST. THE TEST SEQUENCE IS AS FOLLOWS:
-
- 1. A "BACKGROUND" PATTERN OF ALL 1'S IS WRITTEN INTO A 64 BYTE
- BYTE PORTION OF A 4K BYTE BLOCK OF MEMORY.
-
- 2. THE COMPLEMENT OF THE TEST CELL IS WRITTEN INTO THE TEST
- CELL, FOR THE CURRENT TEST COLUMN.
-
- 3. TEST CELL ROW'S ARE READ BY ALTERNATELY READING THE TEST
- CELL AND LOCATIONS +64 ADDRESS'S FROM THE TEST CELL (E.G.
- TEST CELL +64 (N), WHERE N=1,2,3,.... ,63).
-
- 4. READ THE TEST CELL, THEN WRITE THE TEST CELL'S COMPLEMENT
- INTO THE TEST CELL, SO THAT IT IS IN IT'S ORIGINAL
- "BACKGROUND" STATE.
-
- 5. READ TWO CELLS FOLLOWING THE TEST CELL FOR REFRESH CHECK.
-
- 6. REPEAT STEP 5 FOR ALL CELLS OF THE CURRENT TEST COLUMN, AND
- EVERY OTHER COLUMN (E.G. READ CELLS 3,6,9,....63;
- 2,4,9,...62; 1,4,7,.....61; ETC., ETC.)
-
- 7. REPEAT STEPS 2 THRU 6 FOR ALL COLUMNS.
-
- 8. WRITE A "BACKGROUND" PATTERN OF ALL 0'S FOR 64 BYTES IN THE
- 4K BYTE MEMORY BLOCK.
-
- 9. REPEAT STEPS 2 THRU 7.
-
- 10. REPEAT STEPS 1 THRU 9 FOR THE NEXT SEQUENTIAL 64 BYTES IN
- THE 4K BYTE MEMORY BLOCK.
-
- ALL FAILURE TYPE REVEALED INDICATES EITHER UNSATISFACTORY
- ADDRESS TRANSITIONS BETWEEN EVERY CELL AND THE POSITION OF THE
- CELL'S ROW, DESTRUCTION OF STORED DATA DUE TO NOISE COUPLING
- AMOUNG CELLS IN THE SAME COLUMN, OR REFRESH ERRORS.
-
-
- F. WALKING PATTERNS MEMORY TEST
-
- MEMORY ERRORS OCCURRING DURING THE WALKING PATTERNS MEMORY
- TEST WILL BE DISPLAYED ON THE REMOTE CONSOLE AS FOLLOWS:
-
- ERROR AT ADDRESS=NNNN READ BACK NN, EXPECTED NN
- LAST ADDRESS WRITTEN WAS NNNN, PATTERN WAS NN
-
-
- THE TEST SEQUENCE IS AS FOLLOWS:
-
- 1. WRITE A "BACKGROUND" PATTERN OF ALL 1'S FOR 256 BYTES IN A
- 4K BYTE MEMORY BLOCK.
-
- 2. WRITE THE COMPLEMENT OF THE TEST CELL INTO THE TEST CELL.
-
- 3. READ THE REMAINING 256 BYTES, IN THE 4K BYTES OF THE BLOCK.
-
- 4. READ THE TEST CELL.
-
- 5. WRITE THE COMPLEMENT OF THE TEST CELL BACK TO IT'S ORIGINAL
- "BACKGROUND" STATE.
-
- 6. REPEAT STEPS 2 THRU 5.
-
- 7. WRITE A "BACKGROUND" PATTERN OF ALL 0'S FOR 256 BYTES IN THE
- 4K BYTE MEMORY BLOCK.
-
- 8. REPEAT STEPS 2 THRU 6.
-
- 9. REPEAT STEPS 1 THRU 8 FOR THE NEXT SEQUENTIAL 256 BYTES IN
- THE 4K BYTE MEMORY BLOCK.
-
- THE FAILURE TYPES REVEALED ARE INTERNAL MULTIPLE ADDRESS
- SELECTION,DESTRUCTION OF STORED DATA DUE TO NOISE COUPLING
- WITHIN A COLUMN,AND SLOW SENSE AMPLIFIER RECOVERY.
-
-
- G. OPERATOR ERROR MESSAGES
-
- ANY NON-HEXIDECIMAL KEYBOARD ENTRIES ON THE REMOTE CONSOLE WILL
- BE PROMPTED WITH A "?" CHARACTER, AND A RETURN TO THE COMMAND
- MONITOR. ANY ATTEMPT TO TEST "OUT OF RANGE" OF ADDRESS
- SELECTIONS WILL PROMPT WITH:
-
-
- INVALID MEMORY ADDRESS
-
-
- TESTING OF MEMORY IS NOT ALLOWED BELOW ADDRESS 1000, OR ABOVE
- FFFF, ALSO THE LOW MEMORY ADDRESS MAY NOT BE GREATER THAN THE
- HIGH MEMORY ADDRESS, ANY ADDRESS RANGE FROM 1000 HEX TO FFFF HEX
- MAY BE TESTED .HOWEVER, A MINIMUM DIFFERENCE IN ADDRESS OF 3 IS
- REQUIRED DUE TO THE "PUSH/POP" METHOD OF MEMORY TEST BY THE
- RANDOM PATTERNS MEMORY TEST ("PUSH AND POP" INSTRUCTIONS ARE
- UTILIZED FOR MEMORY ACCESS'S BECAUSE THESE TWO INSTRUCTIONS
- PERFORM THE FASTEST ACCESS OF MEMORY).
-
-
-