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─OCUMENTATION FOR ┴╙

┴╙ IS AN ASSEMBLER FOR THE ├OMMODORE 64.  ┴N ASSEMBLER IS A
PROGRAM USED TO TRANSLATE MACHINE LANGUAGE PROGRAMS FROM
PERSON-READABLE FORM (THE SOURCE PROGRAM) TO A MACHINE-USABLE
FORM (THE OBJECT PROGRAM).  ╘HE ASSEMBLER ALLOWS YOU TO WRITE,
MAINTAIN, AND MODIFY A LARGE, COMPLICATED MACHINE LANGUAGE
PROGRAM.

╧PERATION:

┴╙ REQUIRES THE SOURCE FILE TO BE PUT IN ONE OR MORE TEXT FILES
ON A FLOPPY DISK.  ┴FTER YOU HAVE CREATED THE SOURCE FILES, YOU
RUN ┴╙ AS FOLLOWS:

    LOAD "AS",8
    RUN

┴╙ ASKS YOU FOR THE NAME OF THE SOURCE FILE.  ╔F YOU TYPE
"BLURFO" FOR THE NAME, ┴╙ FIRST LOOKS FOR A FILE NAMED "BLURFO".
╔F IT CANNOT FIND "BLURFO", THEN IT LOOKS FOR "BLURFO.A".  ╔F
IT CANNOT FIND EITHER ONE, IT PRINTS AN ERROR MESSAGE AND EXITS.
╔F IT FINDS EITHER ONE, IT CREATES AN OBJECT FILE CALLED
"BLURFO.O".  ╘HE FILENAME YOU TYPE MUST NOT BE LONGER THAN 14
CHARACTERS, TO MAKE ROOM FOR THE EXTENSION ".O".

╘HEN ┴╙ ASKS YOU IF YOU WANT TO MAKE A LIST FILE.  ┘OU SHOULD
TYPE "Y" OR "N".  ╘HE LIST FILE, WHICH IN THE CURRENT EXAMPLE
WOULD BE NAMED "BLURFO.L", LISTS THE NUMERIC VALUE OF EVERY BYTE
IN THE OBJECT FILE, ALONGSIDE THE ADDRESS AT WHICH THE BYTE WILL
BE LOADED AND THE SOURCE LINE CORRESPONDING TO THAT BYTE.  ╠IST
FILES ARE USEFUL IN DEBUGGING PROGRAMS.

┴LL THESE FILES MUST BE ON A DISK DRIVE WITH DEVICE NUMBER 8
AND, IF A DUAL DRIVE, DRIVE NUMBER 0.

┴FTER OPTIONALLY CREATING THE LIST FILE, ┴╙ BEGINS THE FIRST
PASS.  ╒NLESS THERE IS AN ERROR ON THE DISK DRIVE, YOU WILL NOT
SEE ANYTHING ON THE SCREEN DURING THE FIRST PASS.  ╬O OUTPUT IS
WRITTEN TO EITHER THE OBJECT FILE OR THE OPTIONAL LIST FILE
DURING THE FIRST PASS.  ╘HE ONLY PURPOSE OF THE FIRST PASS IS TO
FIGURE OUT THE ADDRESSES WHERE THE PROGRAM WILL BE LOCATED, AND
THEREBY ASSIGN NUMERIC VALUES TO EACH LABEL AND SYMBOL IN YOUR
PROGRAM (╙EE BELOW FOR MORE ABOUT SYMBOLS AND LABELS).

┴FTER THE FIRST PASS IS COMPLETED, ┴╙ PRINTS THE MESSAGE
"┬EGINNING 2ND PASS" AND DOES JUST THAT.  ─URING THE 2ND PASS,
YOU SHOULD SEE ON THE SCREEN A LISTING OF YOUR SOURCE PROGRAM,
BUT WITH VARIOUS NUMBERS OVER IN THE LEFT MARGIN, AND VARIOUS
ERROR MESSAGES PRECEDING THE ERRONEOUS SOURCE LINES.  ╔F YOU
CHOSE TO MAKE A LIST FILE, THE TEXT YOU SEE ON THE SCREEN WILL
BE THE TEXT YOU GET IN THE LIST FILE.  ═EANWHILE THE OBJECT
PROGRAM IS BEING WRITTEN TO THE OBJECT FILE.

╞INALLY YOU WILL SEE THE MESSAGE "┼RRORS DETECTED: 0" WHICH
INDICATES THAT ┴╙ DID NOT DETECT ANY OF THE ERRORS IN YOUR
PROGRAM.  ╬OTE THAT ANY ERRORS THAT ┴╙ DETECTS ARE, IN A SENSE,
"MERE WARNINGS", IN THAT (EXCEPT FOR ╔/╧ ERRORS), YOU STILL ARE
GIVEN AN OBJECT FILE WHICH CAN BE LOADED AND RUN.

┴T ANY POINT IN EITHER THE FIRST OR SECOND PASS, YOU MAY CUT OFF
THE ASSEMBLY BY HITTING THE ╥╒╬/╙╘╧╨ KEY.  ┘OU SHOULD DELETE THE
INCOMPLETE OBJECT AND LIST FILES WHICH WILL HAVE BEEN CREATED.

┴FTER ┴╙ EXITS, YOU CAN LOAD AND RUN THE OBJECT FILE BY TYPING:

        LOAD "BLURFO.O",8,1
        SYS N

WHERE N IS THE ADDRESS OF THE START OF YOUR PROGRAM.

═ISCELLANOUS SPECIFICATIONS:

┴╙ WILL NOT WORK WITH DISK DRIVES OTHER THAN A ├OMMODORE 1541 OR
AN ═╙─ ╙─-2.  ╔F CHANGES ARE MADE TO THE ╥╧═'S IN THESE MODELS,
IT MAY NOT EVEN WORK WITH THEM.  ┴╙ USES LOCATIONS 2049 TO 40959
(0801 TO 9╞╞╞ IN HEXADECIMAL), AND 251 TO 254 (FB TO FE IN
HEXADECIMAL).  ┴╙ USES LOGICAL FILE NUMBERS 2 AND 3.

─IFFERENCES FROM OTHER ASSEMBLERS:

╘HERE ARE NUMEROUS DIFFERENCS BETWEEN ┴╙ AND OTHER ASSEMBLERS
FOR THE ├-64.  ═ANY OF THESE ARE "ADDED FEATURES" OF ┴╙ WHICH
WILL NOT INTERFERE WITH THE ASSEMBLY OF PROGRAMS WRITTEN FOR
ANOTHER ASSEMBLER.  ╘HE FOLLOWING ARE THE MAJOR DIFFERENCES
WHICH MUST BE TAKEN INTO ACCOUNT TO MODIFY A PROGRAM WRITTEN FOR
ANOTHER ASSEMBLER:

1.  ┼VERY LABEL MUST BE FOLLOWED BY A COLON (":").

2.  ╘HE DIRECTIVE * = N IS NOT SUPPORTED.  ╔N OTHER ASSEMBLERS,
THIS DIRECTIVE IS USED PRIMARILY FOR TWO PURPOSES.  ╘HE FIRST
PURPOSE IS TO ESTABLISH THE ADDRESS FOR THE FIRST BYTE IN THE
OBJECT PROGRAM.  ╞OR THAT PURPOSE, REPLACE:

        * = 2049

WITH:

        .ORIGIN 2049

╘HE SECOND COMMON PURPOSE IS TO ALLOCATE AN AREA OF MEMORY
WITHOUT SPECIFING THE CONTENTS OF THAT MEMORY.  ╞OR THAT
PURPOSE, REPLACE:

        * = * + 1

WITH:

        .BLKB 1

3.  ├OMMODORE'S ASSEMBLER HAS A DIRECTIVE CALLED ".BYT" WITH CAN
BE USED TO GENERATE BOTH NUMERIC AND TEXT DATA.  ╔N ┴╙, THIS
DIRECTIVE IS CALLED ".BYTE", AND ONLY GENERATES NUMERIC DATA,
WHILE THE .ASCII DIRECTIVE GENERATES TEXT DATA.  ╘HEREFORE,
REPLACE:

        .BYT 15, '╘EXT STRING', 0

WITH:

        .BYTE 15
        .ASCII '╘EXT STRING'
        .BYTE 0

4.  ┴╙ LACKS THE MACRO DIRECTIVES, CONDITIONAL ASSEMBLY
DIRECTIVES, AND OTHER SPECIALIZED DIRECTIVES FOUND IN OTHER
ASSEMBLERS.

5.  ┴╙ DOES NOT REQUIRE OR ALLOW THE ".END" DIRECTIVE WHICH MANY
ASSEMBLERS REQUIRE AT THE END OF A SOURCE FILE.  ┴CTUALLY, ┴╙
IGNORES THE .END AS AN UNRECOGNIZED DIRECTIVE, BUT YOU SHOULD
DELETE THE .END TO AVOID THE ERROR MESAGE.

╞ORMAT OF SOURCE FILE:

╘HE SOURCE FILE SHOULD BE A SEQUENTIAL FILE, WITH EACH LINE
TERMINATED BY A ╥┼╘╒╥╬ CHARACATER.  ╠INES ARE LIMITED TO 255
CHARACTERS, NOT INCLUDING THE ╥┼╘╒╥╬ CHARACTER.  ┬LANK LINES ARE
LEGAL, AND SPACES CAN BE PUT IN LIBERALLY TO IMPROVE READABILITY
(EXCEPTIONS: SPACES MAY NOT BE PUT IN THE MIDDLE OF A NUMERAL OR
AN IDENTIFIER).  ╒PPER AND LOWER CASE LETTERS ARE TREATED
IDENTICALLY EXCEPT IN .ASCII OR .ASCIZ DIRECTIVES AND IN
CHARACTER LITERALS.  ┴ SEMICOLON (";") IS USED TO INDICATE THE
BEGINNING OF A COMMENT.  ┴LL TEXT AFTER THE SEMICOLON, AND THE
SEMICOLON ITSELF, IS IGNORED (EXCEPTIONS: TEXT STRINGS IN .ASCII
AND .ASCIZ DIRECTIVES AND CHARACTER LITERALS).

┴ VALID LINE CAN BE ANY OF THE FOLLOWING:

1.  ┴ BLANK LINE.

2.  ┴ SYMBOL DEFINITION, E.G.:

        CURSORDOWN = 17

3.  ┴N INSTRUCTION FOR THE 6510 MICROPROCESOR, E.G.:

        LDA # 0

4.  ┴N ASSEMBLER DIRECTIVE, E.G.:

        .BYTE 5

5.  ┴NY OF THE ABOVE (1-4) PRECEDED BY ONE OR MORE LABELS, E.G.:

        START: STARTLOOP: LDA # 0
        LENGTH: .BYTE 0
        BLANKLINE: ; COMMENT

┬LANK LINES:

┬LANK LINES ARE USEFUL FOR THE FOLLOWING PURPOSES:  TO MAKE THE
SOURCE OR LIST FILE MORE READABLE, TO HOLD A LABEL, AND TO HOLD
COMMENTS.  ╔ APOLOGIZE TO PEOPLE WHO WOULD NOT CONSIDER A LINE
HAVING A LABEL AND/OR A COMMENT TO BE A "BLANK LINE".

╙YMBOL DEFINITIONS:

┴ SYMBOL DEFINITION IS USED TO DEFINE A NAME TO REPRESENT A
NUMERIC VALUE.  ╧NE USE OF SYMBOLS IS TO REFER TO ADDRESSES NOT
LOCATED WITHIN THE OBJECT FILE, FOR EXAMPLE, ╦┼╥╬┴╠ ROUTINES,
PAGE ZERO, THE SPECIAL ADDRESSES USED BY THE VIDEO, SOUND, AND
╔/╧ CHIPS, AND VECTORS:

        CHROUT = 65490
        CURRENT.KEY = 197
        COLOR.MEMORY = $─800
        ┴─╙╥1  = 54277
        CIA1.DATA.PORT.┴ = $DC00
        IRQ.VECTOR = 788

╙YMBOLS CAN BE USED FOR VARIOUS CONSTANTS IN YOUR PROGRAM, TO
MAKE THE PROGRAM EASIER TO UNDERSTAND AND TO MODIFY, E.G.:

        SPACE.CHAR = 32
        DISK.DEVICENUM = 8
        POINTER = 251

╙OMETIMES YOU MAY USE A SYMBOL TO REFER TO A MEMORY LOCATION
WITHIN THE OBJECT FILE.  ╔N GENERAL, LABELS ARE PREFERRED OVER
SYMBOLS FOR THIS PURPOSE.  ╚OWEVER, NOTE THAT THE FOLLOWING ARE
VERY SIMILAR IN EFFECT:

        LOCATION:       ; LABEL
        LOCATION = *    ; SYMBOL

╘HE DIFFERENCE IS THAT A SYMBOL CAN BE REDEFINED MANY TIMES
WITHIN THE PROGRAM WITHOUT ERROR, WHILE A LABEL IS SUPPOSED TO
REFER TO ONLY ONE LOCATION.  ╘HE ONE INSTANCE IN WHICH IT MAKES
SENSE TO USE A SYMBOL IS TO MARK THE BEGINNING OF A LOOP:

        LOOP = *
            ; BODY OF LOOP
            DEX
            BNE LOOP

╙INCE THE ASSEMBLER USES THE MOST RECENTLY-ASSIGNED VALUE OF THE
SYMBOL, THIS PATTERN CAN BE USED FOR MANY LOOPS, WITHOUT HAVING
TO THINK OF DISTINCT NAMES FOR THE START OF EACH LOOP.  ┬UT NOTE
THAT THIS PATTERN WILL FAIL MISERABLY FOR A FORWARD BRANCH, OR
FOR A LOOP WITHIN A LOOP.

┬ECAUSE THE FIRST PASS OF THE ASSEMBLER IS DEVOTED TO DEFINING
LABELS AND SYMBOLS, YOU CAN REFER TO A SYMBOL OR LABEL THAT IS
DEFINED LATER IN THE SOURCE FILE.  ╘HIS IS CALLED A "FORWARD
REFERENCE".  ═ORE PRECISELY, YOU ARE ALLOWED ONE LEVEL OF
FORWARD REFERENCE.  ╞OR EXAMPLE:

        A = B + 40
        B = 1024

IS LEGAL, BUT:

        A = B
        B = C
        C = 100

IS NOT LEGAL.  ┘OU SHOULD NOT, HOWEVER, USE EVEN A SINGLE-LEVEL
FORWARD REFERENCE IN A .BLKB OR .BLKW DIRECTIVE.  (╘HESE
DIRECTIVES ARE DESCRIBED BELOW).  ╘HE ASSEMBLER USES THESE
DIRECTIVES IN THE FIRST PASS TO FIGURE OUT HOW MUCH MEMORY TO
ALLOCATE.  ╔F A SYMBOL USED IN A .BLKB OR .BLKW DIRECTIVE IS
UNDEFINED ON THE FIRST PASS, THEN ALL SUBSEQUENT LABELS WILL BE
DEFINED INCORRECTLY.  ╙YMBOLS THAT REFER TO PAGE ZERO SHOULD BE
DEFINED BEFORE THEY ARE USED.  ╙INCE INSTRUCTIONS REFERRING TO
PAGE ZERO USUALLY TAKE 2 BYTES, AS OPPOSED TO 3 BYTES FOR
ADDRESSES ON ANY OTHER PAGE, THE ASSEMBLER NEEDS TO KNOW DURING
THE FIRST PASS WHETHER AN INSTRUCTION REFERS TO PAGE ZERO OR
NOT.  ╔F THE ADDRESS IS SPECIFIED BY AN UNDEFINED SYMBOL, THE
ASSEMBLER ASSUMES THAT THE ADDRESS IS ╬╧╘ ON PAGE ZERO.  ╔F THIS
ASSUMPTION PROVES INCORRECT, ALL SUBSEQUENTLY-DEFINED LABELS
WILL BE DEFINED INCORRECTLY.  ╘HEREFORE, ALL SYMBOLS REFERRING
TO PAGE ZERO ═╒╙╘ BE DEFINED BEFORE THE INSTRUCTIONS THAT REFER
TO THE SYMBOLS.

╙INCE IT IS AN ERROR TO REDEFINE A LABEL, IT IS ALSO AN ERROR TO
DEFINE A SYMBOL WITH THE SAME NAME AS A LABEL.

╔DENTIFIERS:

┴N "IDENTIFIER" IS THE NAME USED FOR A SYMBOL OR LABEL.  ┴N
IDENTIFIER MUST START WITH A LETTER, AND CAN HAVE LETTERS,
NUMERIC DIGITS, OR PERIODS FOR SUBSEQUENT CHARACTERS.  ╘HE
LENGTH OF AN IDENTIFIER IS NOT LIMITED OTHER THAN BY THE MAXIMUM
LENGTH (255 CHARACTERS) OF A SOURCE LINE.  ╒PPER AND LOWER CASE
LETTERS ARE TREATED IDENTICALLY IN IDENTIFIERS.  ╘HE NAMES ┴, ╪,
AND ┘ SHOULD NOT BE USED, EVEN THOUGH LEGAL, BECAUSE OTHER
ASSEMBLERS FORBID THEIR USE.  ╘HIS ASSEMBLER ALLOWS THEIR USE,
EXCEPT THAT A LONE ┴ AS AN OPERAND TO A 6510 INSTRUCTION WILL BE
CONFUSED FOR A REFERENCE TO THE 6510'S ACCUMULATER.

┼XAMPLES OF LEGAL IDENTIFIERS:     AND ILLEGAL IDENTIFIERS:

            ╤                       8
            ┴3333333                3┴┴┴┴┴┴┴
            A.B.C                   .A.B.C

═ACHINE INSTRUCTIONS:

(┴FTER ALL, THE WHOLE POINT OF AN ASSEMBLER IS TO LET YOU ENTER
MACHINE INSTRUCTIONS.)  ┴╙ RECOGNIZES THE STANDARD 56
INSTRUCTION MNEMONICS, WHICH YOU MAY TYPE IN EITHER UPPER OR
LOWER CASE.  ┴╙ USES THE STANDARD PUNCTUATION FOR THE VARIOUS
ADDRESSING MODES:

        CLC         ; IMPLIED
        ADC # 1     ; IMMEDIATE
        ASL ┴       ; ACCUMULATOR
        LDX ┌       ; ZERO PAGE
        ORA ┌,╪     ; ZERO PAGE, ╪
        AND ┌,┘     ; ZERO PAGE, ┘
        CPX ┼       ; ABSOLUTE
        LDY ┼,╪     ; ABSOLUTE, ╪
        LDX ┼,┘     ; ABSOLUTE, ┘
        BEQ ┼       ; RELATIVE
        EOR (┌,╪)   ; (INDIRECT,╪)
        SBC (┌),┘   ; (INDIRECT),┘
        JMP (┌)     ; ABSOLUTE INDIRECT

WHERE ┌ IS AN EXPRESSION WHOSE VALUE IS BETWEEN 0-255, AND ┼ IS
AN EXPRESSION WHOSE VALUE IS NOT NECESSARILY BETWEEN 0-255.
(╘HE EXACT DEFINITION OF AN "EXPRESSION" WILL BE GIVEN LATER.)
╬OTE THAT IT IS OFTEN NOT THE PUNCTUATION, BUT THE VALUE OF THE
EXPRESSION, WHICH DISTINGUISHES CERTAIN ADDRESSING MODES.

┘OU MAY, BUT NEED NOT, PUT IN SPACES BEFORE OR AFTER A "(", ")",
",", OR "#".  ┘OU MUST PUT IN A SPACE AFTER THE NAME OF THE
INSTRUCTION IF THE OPERAND STARTS WITH A LETTER.

┼XPRESSIONS:

┴N EXPRESSION IS A BUNCH OF TEXT THAT REPRESENTS A NUMERIC
VALUE.  ╘HE FOLLOWING ARE LEGAL EXPRESSIONS:

1.  ┴ DECIMAL NUMERAL (0 TO 65535):

        1024

2.  ┴ HEXADECIMAL NUMERAL, PRECEDED BY A DOLLAR SIGN:

        $FF
        $─├00

3.  ┴ BINARY NUMERAL, PRECEDED BY A PERCENT SIGN:

        %10000001

4.  ┴ CHARACTER LITERAL, PRECEDED BY AN APOSTROPHE:

        '┴

5.  ┴N IDENTIFIER:

        LOOP
        COLOR.MEMORY
        DISK.DEVICENUM

    ╘HE NUMERIC VALUE OF AN IDENTIFIER IS GIVEN BY ITS MOST
    RECENT DEFINITION AS A SYMBOL OR AS A LABEL.

6.  ╘HE "LOCATION COUNTER", EITHER A PERIOD OR ASTERISK:

        .
        *

    ╘HE NUMERIC VALUE OF THE LOCATION COUNTER IS THE ADDRESS IN
    THE OBJECT PROGRAM CORRESPONDING TO THE BEGINNING OF THE
    CURRENT SOURCE LINE.

7.  ┴N EXPRESSION PRECEDED BY A "UNARY OPERATOR":

        < ┼         ; LOW-ORDER BYTE OF ┼
        > ┼         ; HIGH-ORDER BYTE OF ┼
        - ┼         ; NEGATIVE ┼ (TWO'S COMPLEMENT)
        ? ┼         ; LOGICAL (ONE'S) COMPLEMENT OF ┼

8.  ┴N EXPRESSION FOLLOWED BY A "BINARY OPERATOR" FOLLOWED BY A
SECOND EXPRESSION:

        ┼1 + ┼2     ; ADDITION
        ┼1 - ┼2     ; SUBTRACTION
        ┼1 * ┼2     ; MULTIPLICATION
        ┼1 / ┼2     ; INTEGER DIVISION
        ┼1 % ┼2     ; MODULO (REMAINDER AFTER INTEGER DIVISION)
        ┼1 & ┼2     ; LOGICAL ┴╬─
        ┼1 ! ┼2     ; LOGICAL ╧╥
        ┼1 ^ ┼2     ; ARITHMETIC SHIFT
                    ; LEFT SHIFT IF ┼2 IS POSITIVE
                    ; RIGHT SHIFT IF ┼2 IS NEGATIVE

╔F MORE THAN ONE OPERATOR IS USED IN THE SAME EXPRESSION, THEY
ARE DONE IN THE FOLLOWING ORDER: ? - (NEGATIVE) * % / -
(SUBTRACTION) + & ! ^ < >.  ╔F THE SAME OPERATOR APPEARS TWICE,
EVALUATION IS FROM RIGHT TO LEFT.  ┘OU CAN OVERRIDE THE NORMAL
ORDER OF EVALUATION BY USING BRACKETS ("[" AND "]") AS
PARENTHESES.

╬OTE, HOWEVER, THAT ALL THESE ARITHMETIC OPERATIONS MAY BE DONE
ONLY ON CONSTANT EXPRESSIONS.  ╘HAT IS, YOU CANNOT USE THE ABOVE
OPERATORS TO ADD THE CONTENTS OF VARIOUS MEMORY LOCATIONS.  ╘HE
USEFULNESS OF ELABORATE ASSEMBLER EXPRESSIONS IS PRIMARILY TO
DEFINE ONE SYMBOL IN TERMS OF ANOTHER, SO THAT IF YOU CHANGE ONE
SYMBOL, VARIOUS OTHER SYMBOLS ARE AUTOMATICALLY REDEFINED.

┴SSEMBLER DIRECTIVES:

╘HE ASSEMBLER DIRECTIVES PERFORM VARIOUS MISCELLANEOUS FUNCTIONS:

.BYTE
.BYTE ┌
.BYTE ┌1, ┌2, ... , ┌3

    ╘HE .BYTE DIRECTIVE ALLOCATES ONE OR MORE BYTES IN THE
    OBJECT FILE.  ╔F AN EXPRESSION IS GIVEN, THE EXPRESSION IS
    PUT IN AS THE INITIAL VALUE OF THE BYTE.  ╔F MORE THAN ONE
    EXPRESSION IS GIVEN, SEPARATED BY COMMAS, THAN A BYTE IS
    ALLOCATED FOR EACH EXPRESSION.  ╔F NO EXPRESSION IS GIVEN, A
    SINGLE BYTE IS ALLOCATED WITH AN INITIAL VALUE OF ZERO.  ╧NLY
    THE LOW-ORDER BYTE OF THE EXPRESSION IS USED.

.WORD
.WORD ┼
.WORD ┼1, ┼2, ... , ┼3

    ╘HE .WORD DIRECTIVE IS VERY SIMILAR TO THE .BYTE DIRECTIVE,
    BUT TWO BYTES ARE ALLOCATED FOR EACH EXPRESSION, THE FIRST
    FOR THE LOW-ORDER BYTE AND THE SECOND FOR THE HIGH-ORDER
    BYTE.  ╔F NO EXPRESSION IS GIVEN, THEN TWO BYTES ARE
    ALLOCATED, BOTH INITIALIZED TO ZERO.

    ╬OTE THAT

            .WORD ┼

    IS EXACTLY EQUIVALENT TO:

            .BYTE < ┼, > ┼

.BLKB
.BLKB ┼

    ╘HE .BLKB DIRECTIVE IS USED TO ALLOCATE MEMORY IN THE OBJECT
    PROGRAM WITHOUT SPECIFYING THE INITIAL VALUES.  ╔F AN
    EXPRESSION IS GIVEN, THAT NUMBER OF BYTES IS ALLOCATED.  ╔F
    NO EXPRESSION IS GIVEN, 1 BYTE IS ALLOCATED.  ┬UT IF THE
    VALUE OF THE EXPRESSION IS ZERO, NO BYTES ARE ALLOCATED.  ╔F
    THE EXPRESSION IS NEGATIVE OR GREATER THAN 32767, AN ERROR
    MESSAGE IS GENERATED AND NO BYTES ARE ALLOCATED.

.BLKW
.BLKW ┼

    ╘HE .BLKW DIRECTIVE IS SIMILAR TO THE .BLKB DIRECTIVE,
    EXCEPT THAT THE NUMBER OF BYTES TO BE ALLOCATED IS
    MULTIPLIED BY TWO.

.ASCII "╘EXT STRING"

    ╘HE .ASCII DIRECTIVE IS USED TO ALLOCATE MEMORY IN THE
    OBJECT PROGRAM FOR A TEXT STRING.  ╧NE BYTE IS ALLOCATED FOR
    EACH CHARACTER IN THE TEXT STRING, AND EACH BYTE IS
    INITIALIZED WITH THE CHARACTER CODE (NOT THE CODE FOR SCREEN
    MEMORY) FOR THE CHARACTER FROM THE SOURCE LINE.  ╘HE TEXT
    STRING CAN BE DELIMITED BY ANY CHARACTER NOT FOUND WITHIN
    THE TEXT STRING, WITH THE EXCEPTION THAT A SEMICOLON (";"),
    A SPACE, OR A ╥┼╘╒╥╬ CHARACTER MAY NOT BE USED AS THE
    DELIMITER.  ╬OTE THAT THE CHARACTER CODES ARE NOT TRUE ┴╙├╔╔
    BUT THE ├OMMODORE VARIANT, SOMETIMES CALLED ╨┼╘╙├╔╔.

.ASCIZ /╘EXT STRING/

    ╘HE .ASCIZ DIRECTIVE IS SIMILAR TO THE .ASCII DIRECTIVE,
    EXCEPT THAT A ZERO BYTE IS ALLOCATED AFTER THE TEXT STRING.

.ORIGIN ┼

    ╘HE .ORIGIN DIRECTIVE IS USED AT THE BEGINNING OF THE SOURCE
    FILE TO SPECIFY THE ADDRESS TO BE USED FOR THE FIRST BYTE IN
    THE OBJECT FILE.  ╔N FACT, THE .ORIGIN DIRECTIVE NEED NOT BE
    LITERALLY ON THE FIRST LINE OF THE SOURCE FILE, BUT IT MUST
    COME BEFORE ANY SOURCE LINES THAT ALLOCATE MEMORY IN THE
    OBJECT FILE.  ╔F YOU DO NOT INCLUDE A .ORIGIN DIRECTIVE, THE
    DEFAULT ORIGIN IS 49152 ($├000 HEXADECIMAL).

.PRINT ┼ TEXT

    ╘HE .PRINT DIRECTIVE IS USED TO PRINT MESSAGES ON THE
    TERMINAL AND INTO THE OPTIONAL LIST FILE.  ╘HE EXPRESSION
    FOLLOWING THE .PRINT IS EVALUATED.  ╘HE NUMERIC VALUE OF
    THAT EXPRESSION IS PRINTED, IN DECIMAL, TO THE SCREEN AND
    INTO THE OPTIONAL LIST FILE, FOLLOWED BY ANY OTHER TEXT ON
    THE SOURCE LINE.  ╘HE MAIN USE OF THE .PRINT DIRECTIVE IS TO
    PRODUCE A MEMORY MAP RATHER THAN A FULL LISTING OF EVERY
    LINE OF THE PROGRAM.  ╘HE OUTPUT FROM THE .PRINT DIRECTIVE
    IS PERFORMED EVEN IF THE .NOLIST DIRECTIVE IS IN EFFECT.

    ┼XAMPLES:

            .PRINT SUBROUTINE SUBROUTINE
            SUBROUTINE:
                ...
                ...
                RTS

            .PRINT * - SUBROUTINE, LENGTH OF SUBROUTINE

            .PRINT * ┼ND OF FILE
            .PRINT * - START, ╙IZE OF FILE

.NOLIST

    ╘HE .NOLIST DIRECTIVE TURNS OFF THE LISTING OF EVERY SOURCE
    LINE TO THE SCREEN AND TO THE OPTIONAL LIST FILE.  ╘HE
    OUTPUT OF THE .PRINT DIRECTIVE IS STILL PERFORMED, HOWEVER.

.LIST

    ╘HE .LIST DIRECTIVE TURNS BACK ON THE LISTING OF EVERY
    SOURCE LINE, AFTER A PREVIOUS .NOLIST DIRECTIVE.  ╔N THIS
    WAY, YOU CAN MAKE A LIST FILE OF ONLY THOSE PARTICULAR
    ROUTINES WHICH YOU ARE INTERESTED IN DEBUGGING.

.INCLUDE IDENTIFIER

    ╘HE .INCLUDE DIRECTIVE IS USED TO INCORPORATE ANOTHER SOURCE
    FILE AS THOUGH IT HAD BEEN MERGED WITH THE PRINCIPAL SOURCE
    FILE.  ╘HIS ALLOWS YOU TO HAVE A LIBRARY OF COMMON
    SUBROUTINES WITHOUT HAVING TO MAKE A SEPARATE COPY OF THE
    SUBROUTINES IN EACH PROGRAM IN WHICH YOU USE THEM.  ╔T IS
    ALSO USEFUL TO MAKE SEVERAL, SLIGHTLY DIFFERENT VERSIONS OF
    THE SAME PROGRAM.  ╔T IS ALSO USEFUL TO DIVIDE UP A LARGE
    PROGRAM FOR MORE CONVENIENT EDITING.  ╔T IS ALSO USEFUL FOR
    INCORPORATING A LIST OF COMMON SYMBOL DEFINITIONS, SUCH AS
    THE ADDRESSES OF THE ╦┼╥╬┴╠ ROUTINES.  ╘HE ASSEMBLER FIRST
    LOOKS FOR A FILE WHOSE NAME IS GIVEN BY THE IDENTIFIER
    (CONVERTED TO LOWER CASE).  ╔F THAT FILE CANNOT BE FOUND, IT
    ADDS ".A" TO THE FILENAME AND LOOKS FOR THAT NAME.  ┴FTER
    THE ASSEMBLER HAS FINISHED PROCESSING THE INCLUDED SOURCE
    FILE, IT RETURNS TO THE PRINCIPAL SOURCE FILE AND CONTINUES
    FROM THE LINE FOLLOWING THE .INCLUDE DIRECTIVE.  ╘HE
    INCLUDED FILE CAN INCLUDE A "THIRD-LEVEL" SOURCE FILE, BUT
    THERE IS A MAXIMUM OF FOUR LEVELS OF INCLUSION.

═ODIFICATIONS:

┴╙ REQUIRES ALL THE FILES IT ACCESSES TO BE ON A SINGLE DISK
DRIVE, WHICH IS DEVICE NUMBER 8 BY DEFAULT.  ╘O CHANGE THE
DEVICE NUMBER FROM 8 TO 9, POKE 2061,9.

┼RROR MESSAGES:

╞ILE NAME MAY BE 1 TO 14 CHARS LONG

    ╔F, WHEN THE ASSEMBLER INITIALLY ASKS FOR THE NAME OF THE
    SOURCE FILE, YOU HIT THE ╥┼╘╒╥╬ KEY WITH NO NAME, OR GIVE A
    NAME LONGER THAN 14 CHARACTERS, YOU GET THIS MESSAGE.

├OULDN'T CREATE OBJECT FILE:
├OULDN'T CREATE LIST FILE:
┼RROR READING SOURCE FILE:
┼RROR WRITING TO LIST FILE:
┼RROR WRITING TO LIST FILE:
┼RROR CLOSING OBJECT FILE:
┼RROR CLOSING LIST FILE:
┼RROR RE-READING SOURCE FILE

    ┴LSO PRINTS THE ERROR MESSAGE GIVEN BY THE DISK DRIVE

├OULDN'T OPEN CONTROL OR RANDOM CHANNEL

    ═AY INDICATE THAT YOU RAN ┴╙ WHILE FILE CHANNELS WERE STILL
    OPENED FROM ANOTHER PROGRAM.

╠INE TOO LONG

    ╙OURCE LINE LONGER THAN 255 CHARACTERS.

┴SSEMBLY TERMINATED BY ╙╘╧╨ KEY

╒NRECOGNIZED STATEMENT

    ╘HE FIRST NON-BLANK CHARACTER IN THE SOURCE LINE WAS NEITHER
    A LETTER NOR A PERIOD.  ═AY INDICATE THAT THE SOURCE LINE
    CONTAINS A NON-PRINTING CHARACTER.

╒NRECOGNIZED OPCODE

    ═AY INDICATE A MISSPELLED OPCODE, OR THE ACCIDENTAL OMISSION
    OF THE COLON AFTER A LABEL OR OF THE = FOLLOWING A SYMBOL
    DEFINITION.

┼XTRA INPUT IGNORED

    ═AY INDICATE THE OMISSION OF THE SEMICOLON PRECEDING A
    COMMENT.  ═AY ALSO INDICATE THE OMISSION OF AN OPERATOR FROM
    AN EXPRESSION.

╬O CHARACTER AFTER '

    ╔NDICATES THAT AN APOSTROPHE WAS THE LAST CHARACTER IN THE
    SOURCE LINE.

═ALFORMED EXPRESSION

╫ARNING - EXTRA [

╫ARNING - EXTRA ]

╫ARNING - ARITHMETIC OVERFLOW

    ╔NDICATES AN ARITHMETIC OPERATION WHOSE RESULT REQUIRED MORE
    THAN 16 BITS.

╫ARNING - DIVISION BY ZERO

╔NTERNAL ASSEMBLER ERROR

    ╘HIS MESSAGE INDICATES THAT THE ASSEMBLER WAS NOT ABLE TO
    EVALUATE AN EXPRESSION PROPERLY.

╙ECOND ARGUMENT TO ^ MUST BE -15 TO 15

╒NDEFINED SYMBOL: IDENTIFIER

╙YMBOL TABLE FULL

    ╔NDICATES THAT THE ASSEMBLER WAS NOT ABLE TO CREATE A LABEL
    OR SYMBOL BECAUSE OF INSUFFICIENT AVAILABLE MEMORY.

╫ARNING - REDEFINING LABEL:

    ╘HIS MAY INDICATE THAT THE SOURCE FILE HAS TWO DIFFERENT
    LABELS WITH THE SAME NAME, OR A SYMBOL AND A LABEL WITH THE
    SAME NAME.  ╔T ALSO MAY INDICATE A DUPLICATE NAME FROM AN
    INCLUDE FILE.  ╔F, HOWEVER, YOU GET THIS ERROR MESSAGE FOR
    EVERY LABEL IN THE SOURCE FILE, IT MEANS THAT THE VALUE OF
    THE LABELS CHANGED FROM THE FIRST PASS TO THE SECOND PASS.
    ╘HIS, IN TURN, USUALLY MEANS THAT A SYMBOL WAS USED IN A
    .BLKB OR .BLKW DIRECTIVE BEFORE IT WAS DEFINED, OR THAT A
    SYMBOL REFERRING TO PAGE ZERO WAS USED BEFORE IT WAS
    DEFINED.

╒NRECOGNIZED ADDRESSING MODE

╔MPROPER ADDRESSING MODE FOR OPCODE

    ╬OT ALL THE POSSIBLE ADDRESSING MODES CAN BE USED FOR ANY
    PARTICULAR OPCODE.  ╙EE THE ├-64 ╨ROGRAMMER'S ╥EFERENCE
    ═ANUAL, OR ANY OTHER BOOK ABOUT THE 6502, FOR A DESCRIPTION
    OF THE PERMISSIBLE ADDRESSING MODES FOR EACH OPCODE.

┼XPRESSION TRUNCATED

    ┴N EXPRESSION USED WITH AN OPCODE IN IMMEDIATE MODE OR USED
    IN A .BYTE DIRECTIVE WAS NOT WITHIN THE RANGE -256 TO 255.

┬RANCH OUT OF RANGE

    ╘HE VARIOUS BRANCH INSTRUCTIONS FOR THE 6510 MAY ONLY BE
    USED TO BRANCH TO A LOCATION LESS THAN 254 BYTES BEFORE THE
    BRANCH INSTRUCTION OR LESS THAN 253 BYTES AFTER THE BRANCH
    INSTRUCTION.  ╘HIS ERROR MESSAGE IS ALSO OFTEN GIVEN IF THE
    EXPRESSION SPECIFYING THE ADDRESS USES AN UNDEFINED
    IDENTIFIER.

╒NRECOGNIZED DIRECTIVE

    ┴ SOURCE LINE BEGAN WITH A PERIOD, BUT WAS NOT ONE OF THE
    ASSEMBLER DIRECTIVES DESCRIBED ABOVE.

╫ARNING - EXTRA COMMA

    ┴ .BYTE OR .WORD DIRECTIVE HAD A TRAILING COMMA AFTER THE
    LAST EXPRESSION.

╫ARNING - COMMA INSERTED

    ┴ .BYTE OR .WORD DIRECTIVE HAD TWO EXPRESSIONS NOT SEPARATED
    BY A COMMA.

┴RGUMENT MUST BE POSITIVE

    ╘HE ARGUMENT TO .BLKB OR TO .BLKW WAS NEGATIVE, OR GREATER
    THAN 32767.

═ISSING STRING

    ┴N .ASCII OR .ASCIZ DIRECTIVE DID NOT HAVE A TEXT STRING, OR
    USED A SEMICOLON AS THE DELIMITER.

╒NTERMINATED STRING

    ┴N .ASCII OR .ASCIZ DIRECTIVE WAS FOLLOWED BY A TEXT STRING
    WHICH WAS NOT FOLLOWED BY THE DELIMITER CHARACTER PRECEDING
    THE TEXT STRING.

╧RIGIN CAN ONLY BE SET ONCE AT START

    ╘HE SOURCE FILE CONTAINED TWO .ORIGIN DIRECTIVES, OR
    CONTAINED AN .ORIGIN DIRECTIVE AFTER A SOURCE LINE WHICH
    ALLOCATED MEMORY.  ═AY INDICATE THAT AN INCLUDE FILE HAD AN
    .ORIGIN DIRECTIVE.

╞ILENAME MUST START WITH A LETTER

    ┴ .INCLUDE DIRECTIVE WAS NOT FOLLOWED BY AN IDENTIFIER.

┴LREADY AT MAXIMUM DEPTH OF INCLUDES

    ╧NLY FOUR LEVELS OF SOURCE FILES ARE ALLOWED.

├OULDN'T OPEN INCLUDE FILE:

    ╨RINTS THE ERROR MESSAGE FROM THE DISK DRIVE

╞ILE NUMBER NOT OPENED
╞ILE NUMBER OUT OF RANGE
╞ILE NUMBER ALREADY IN USE
─IRECTORY NOT UPDATED

    ╘HESE MESSAGES INDICATE INTERNAL ERRORS IN THE FILE-HANDLING
    ROUTINES USED BY THE ASSEMBLER.

╞OR MORE INFORMATION, CALL ╠EW ╠ASHER AT [phone]