The Fred Fish Collection 1.5/ffcollection-1-5-1992-11.iso/ff_progs/prog-asm/as6502.lzh/AS6502/AS6502.NOTES

Text File | 1991-08-16 | 6.3 KB | 199 lines

                        aaaaaassssss666666555555000000222222 UUUUUUsssssseeeeeerrrrrr NNNNNNooooootttttteeeeeessssss                  Page 1


SSSSSSOOOOOOUUUUUURRRRRRCCCCCCEEEEEE LLLLLLIIIIIINNNNNNEEEEEE FFFFFFOOOOOORRRRRRMMMMMMAAAAAATTTTTT:

     <label> <operation> <operand> <comment>

Each field is terminated by one or more spaces, a tab  or  a  ';'
(which begins the comment field immediately).

LLLLLLAAAAAABBBBBBEEEEEELLLLLL FFFFFFIIIIIIEEEEEELLLLLLDDDDDD:

If first character is ';', entire line is a  comment.   If  first
character is space, label field is null.  Labels are alphanumeric
strings beginning with 'a' through 'z', 'A' through  'Z',  under-
score  or  period  followed by any of the above characters or '0'
through '9'.  Currently, labels are limited to 19 characters.  A,
X, Y, a, x and y are reserved labels.

OOOOOOPPPPPPEEEEEERRRRRRAAAAAATTTTTTIIIIIIOOOOOONNNNNN FFFFFFIIIIIIEEEEEELLLLLLDDDDDD:

Upper and lower case letters are equivalent.   Machine  operation
mnemonics are:

     ADC     BMI     CLD     DEX     JSR     PHA     RTS     STY
     AND     BNE     CLI     DEY     LDA     PHP     SBC     TAX
     ASL     BPL     CLV     EOR     LDX     PLA     SEC     TAY
     BCC     BRK     CMP     INC     LDY     PLP     SED     TSX
     BCS     BVC     CPX     INX     LSR     ROL     SEI     TXA
     BEQ     BVS     CPY     INY     NOP     ROR     STA     TXS
     BIT     CLC     DEC     JMP     ORA     RTI     STX     TYA

Pseudo operation mnemonics are:

     =      equate label name to operand field  value  (space  is
            not needed to terminate this operation).
     *=     set location counter to operand field value (space is
            not needed to terminate this operation).
     .WORD  assign 16 bit value of operand field to next two  lo-
            cations; low byte of value first, then high byte.
     .DBYT  assign 16 bit value of operand field to next two  lo-
            cations; high byte of value first, then low byte.
     .BYTE  assign 8 bit value of operand field to next location.
     .NLST  turn listing mode off (this source line is not  list-
            ed).
     .LIST  turn listing mode on (normal mode) (this source  line
            is not listed).
     .PAGE  start a new listing page.  Optionally specify a title
            for the page heading.  (this source line is not list-
            ed).

OOOOOOPPPPPPEEEEEERRRRRRAAAAAANNNNNNDDDDDD FFFFFFIIIIIIEEEEEELLLLLLDDDDDD:

Operand field expressions use infix notation  and  are  evaluated
strictly from left to right.  No imbedded spaces are permitted.

Operand field terms include labels and numbers.  Asterisk (*)  is
the  label  for  the location counter value.  Numbers are binary,
octal, decimal, hexadecimal or ASCII.  Number type  is  indicated
by the first character of the number string as follows:






                        aaaaaassssss666666555555000000222222 UUUUUUsssssseeeeeerrrrrr NNNNNNooooootttttteeeeeessssss                  Page 2



     %       binary prefix
     @ or 0  octal prefix
     1 - 9   decimal by default (prefix is part of number)
     $       hexadecimal prefix
     '       ASCII character prefix
     "       ASCII character string prefix and suffix; in the
             string, \t is a tab character, \n is a new line.

Operand field operations and the corresponding symbols are:

     +       addition
     -       subtraction
     /       division
     *       multiplication
     %       modulo (remainder after integer division)
     ^       logical exclusive OR
     &       logical AND
     |       logical OR
     <       low byte
     >       high byte

Addressing modes are represented as follows:
      lda =aa         immediate addressing
      lda #aa         immediate addressing, alternate
      lda D           direct addessing
      LDA aa          page zero addressing, aa < 256
      asl A           accumulator addressing
      brk             implied addressing
      lda (aa,X)      indirect,X addressing
      lda (aa),Y      indirect,Y addressing
      lda aa,X        zero page,X addressing
      lda D,X         absolute,X addressing
      lda D,Y         absolute,Y addressing
      bcc *-$10       relative addressing
      jmp (D)         indirect addressing
      ldx aa,Y        zero page,Y addressing

     EEEEEERRRRRRRRRRRROOOOOORRRRRR MMMMMMEEEEEESSSSSSSSSSSSAAAAAAGGGGGGEEEEEESSSSSS:

     Invalid operation code
     Invalid argument count (when as6502 was invoked)
     Open error for file
     Creat error for object file 6502.out
     Close error
     Close error (6502.out)
     Symbol table full
     Label multiply defined
     Sync error (pass 1 symbol value not equal pass 2 symbol value)
     Invalid branch address
     Operand field missing
     Invalid addressing mode
     Operand field size error
     Undefined symbol in operand field
     Invalid operand field

IIIIIINNNNNNVVVVVVOOOOOOKKKKKKIIIIIINNNNNNGGGGGG aaaaaassssss666666555555000000222222:






                        aaaaaassssss666666555555000000222222 UUUUUUsssssseeeeeerrrrrr NNNNNNooooootttttteeeeeessssss                  Page 3


     as6502 {-ilnmos} {-p -t -w } <source files descriptions>

Options:

     -i   ignore any .nlst pseudo operations
     -l   list errors only
     -n   print addresses as <high byte><low byte>,
          rather than as <low byte>:<high byte>.
     -o   generate ASCII object output in file 6502.out,
          format is
               ;<address lo><address hi><data>
     -s   print symbol table at end of listing
     -m   output the object file in standard MOS Technology format.


     Parameters:
     -p   specify the page length.
     -t   specify the symbol table size.
     -w   specify the print line size.

                     J. H. Van Ornum, JHS  3/3/87