Power-Programmierung/CD2.mdf/c/library/xplatfrm/motxas/readme.txt

Text File | 1990-12-23 | 13KB | 260 lines

                            Motorola's Freeware Assemblers
                                    "Version 1.2"


                 Welcome to "Version 1.2" of Motorola's Freeware
          Assemblers.  I've put the version number in quotes because I'm
          not certain that anyone's been keeping track...  I consider the
          correction and enhancements made by Bruce Olney as Version 1.1,
          so I'm calling my contribution "Version 1.2".  My contribution
          consists of activation of the END directive, corrected forward
          reference handling, allowance of long file or path names (MAC
          users, this may help you), improved handling of multiple source
          files, improved error detection and reporting (both input code
          and assembler operation), allowance of a little more leeway in
          operand syntax, and some miscellaneous changes.
                 This file contains a more detailed listing of the changes
          mentioned above, as well as some corrections for another file
          you'll want:  ASREF.MAN.  ASREF.MAN is the manual for the
          freeware assemblers.  Look for ASREF.ARC, which can be "de-
          archived" with PKXARC to yield ASREF.MAN.  If you're using an IBM
          PC or compatible and don't want to compile the assemblers
          yourself, look for FASPC1P2.ARC.  It contains the assemblers
          ready-to-use (compiled with QuickC 2.0 using compact memory
          model, except was ASHC5 compiled with QuickC 2.5).  Hopefully, a
          generous MAC user will upload an archive of the assemblers
          compiled for the MAC.  I'll take the liberty of suggesting the
          name FASMA1P2.ARC.  The file ASEMBLER.DOC (included in the
          archive you got this file from) contains a brief rundown on the
          freeware assemblers for those acquainted with Motorola's other
          development products.  I have edited ASEMBLER.DOC only a little;
          it does not include much of the information presented here.
                 I have used good 68HCx05 code to test AS5, so it should be
          nearly bug free.  Since most of the code is common to all the
          assemblers, the others should be in reasonably good shape but
          are untested.  If you discover bugs, please report them on
          Motorola's Freeware BBS.  If you wish to contact me about these
          assemblers, I may be reached (in order of preference) on

                 Motorola's Freeware BBS       [phone]
                 the JDR Microdevices BBS      [phone]
                 or the Radio-Electronics BBS  [phone]

                 The files AS0.C, AS1.C, AS4.C, AS5.C, ASHC5.C, AS9.C, and
          AS11.C are used to compile the assemblers.  Each of these files
          acts as a list of the source files to use for its version of the
          assemblers.  Either copy all of the .C files and all of the .H
          files to the disk or directory you want to compile on, or copy
          only the AS*.C file you want and the files mentioned in it to the
          disk or directory you want to compile on.  Then tell your C
          compiler to compile the AS*.C file; the others will be read in
          automatically.  If you're working on an 80x86 machine (IBM PC or
          Clone) you should use either the small or compact memory model.
          The small model provides slightly smaller program size and
          slightly faster execution, while the compact model provides more












          space for the assemblers to store data.
                 Thank you to all who have worked on these assemblers
          before me, and best wishes to all who use them.  Just in case any
          copyright worries should pop up, I hereby release to the public
          domain this document and all of the changes and I have written
          into these assemblers.

                                                 Greg Thoman
                                                 1990 December 24


          THE END DIRECTIVE

                 Past versions of the assemblers ignored the END directive.
          Now, END terminates assembly of the current source file without
          affecting assembly of subsequent source files and lets you
          specify your program's entry point.  The syntax is:

          [label]   END [expression]  [;comment]

          where the brackets indicate optional items and are NOT included
          in your code.  The label follows the same rules as all other
          labels:  it must start in the first column, must begin with a
          letter, an underscore, or a period, and may contain letters,
          digits, underscores, periods, and dollar signs.  The expression,
          if used, sets your program's entry point.  Thus, it will usually
          be a program label; however, it can be any valid expression that
          evaluates to the address you want.
                 Comments following the END directive should start with a
          semicolon to prevent confusion in case there's no expression to
          evaluate.  The expression evaluator will probably find a comment
          distasteful.
                 You may use the END directive at the end of each source
          file in a group, and may use it more than once in the same file
          (the first END will stop assembly of that file, so the assembler
          will never see any later ENDs).  If the assembler encounters END
          with an expression more than once you'll get a warning if the
          expressions evaluate to the same address.  If the expressions
          evaluate to different addresses, you'll get an error.


          FORWARD REFERENCE HANDLING

                 The assemblers were deleting the forward reference file
          before attempting to use it.  "Version 1.2" deletes the forward
          reference file after assembly is finished.  This may reduce the
          number of "phasing errors" you run into, but they'll still be
          around.


          LONG FILE OR PATH NAMES

                 The assemblers now attempt to use your C compiler's
          definition of FILENAME_MAX to set the filename buffer size.












          I believe this is an ANSI item and may not be defined on non-ANSI
          compilers.  If FILENAME_MAX is not defined by your compiler, the
          assemblers will use their maximum buffer size (512 bytes in
          "Version 1.2").  Thus, you should be able to use full path names
          and work among subdirectories.
                 This may help MAC users who have had to run the assemblers
          from the root "folder" of a floppy drive.  Try it out!


          MULTIPLE SOURCE FILES

                 The assembler now outputs the message "  Assembling <file
          name>", where <file name> is the name of the file about to be
          assembled, as it begins assembly of each file in pass 2.  If you
          are having the assembler create a listing file, these messages
          will break the listing file up so you can see which source file
          is which.
                 Warnings and error messages now report the line number
          within the source file where a problem was found instead of the
          cumulative line number.  This makes error correction easier.  The
          listing, cross reference, and symbol table use the cumulative
          line number.


          ERROR DETECTION AND REPORTING

                 Error and warning messages always give the name of the
          source file where a problem was found.
                 Some error messages are now less cryptic, and error
          messages always start with "Error".
                 Use of NUL as a character constant now generates an error
          message.
                 The assemblers now count the number of warnings issued and
          output it after assembly.
                 Warnings are output on both passes.  If you're generating
          a listing, it will start with a list of warning messages and each
          suspect line will be accompanied by its warning message.
                 The assemblers now warn of over-length labels and error on
          over-length mnemonics or directives.
                 Any unrecognized option on the command line is a fatal
          error, and the assembler will output a list of allowed options.
                 All memory allocation operations are checked for failure.
                 All file operations are checked for failure.


          OPERAND SYNTAX

                 Character constants are now allowed to have a closing
          single quote.  Thus, 'a and 'a' are the same to the assemblers.
                 The OPT directive now allows multiple options, as
          described in ASREF.MAN.
                 The assemblers now allow comma-delimited lists to contain
          whitespace after each comma.  Thus, "OPT NOL,C" is the same as
          "OPT NOL, C".  This also works for data initialization and MC6811












          register lists.  Note that as always, whitespace is NOT allowed
          in indexed addressing.  "LDA DOG,X" is legal, while "LDA DOG, X"
          is not.
                 Except for AS4 and certain 6809 instructions, the
          assemblers interpret an operand consisting only of an index
          register as a request for zero-offset indexed addressing.  Thus,
          "LDA X", "LDA ,X", and "LDA 0,X" all mean to load register A with
          the value whose address is in the X register.  On the 6804 the
          registers are memory locations, so the comma is required to
          prevent confusion.  On the 6809, pushes and pulls interpret a
          register alone as that register, not indexed addressing.
                 Arguments to the OPT directive may now be upper case,
          lower case, or mixed case.
                 The semicolon may be used to start a comment almost
          anywhere on a line.  Unless the semicolon is the first character
          on the line at least one whitespace character should precede it.
          The semicolon does NOT act as a comment starter if it can be
          interpreted as an argument to an FCC directive or if it is
          immediately preceded by a single quote ( '; is a character
          constant, not the start of a comment).


          MISCELLANEOUS

                 Line continuation with the backslash character has
          apparently never existed in these assemblers.  I have not added
          it.
                 When the assemblers truncate listing of a long data group,
          they add a note to the listing to tell you.
                 The buffer size in "Version 1.2" is 512 bytes.  This will
          allow lines up to 510 characters (last two bytes are taken up by
          the line's carriage return and an end-of-string marker).  The
          assemblers will choke on longer lines.
                 When the assemblers encounter "OPT NOC" while listing,
          they output the cumulative cycle count to that point.  The
          cumulative cycle count is also output after the last source line
          if cycle counting is still enabled.
                 AS9 allows TFR from a 16 bit register to an 8 bit
          register, as described in ASREF.MAN.
                 If you want to use the assemblers on an 8 bit machine you
          ought to change all of the data items declared as "int" to
          "short" so that they'll still be long enough for various overflow
          checks to work (unfortunately, this will slow processing).  If
          you use a 32 bit machine and compiler or change some "int" items
          to "long", you'll get a warning if the entry point specified with
          END overflows 16 bits.


          SOME ASREF.MAN CORRECTIONS
                 Page 6:   Parentheses are NOT allowed in expressions.
                 Page 10:  The "no listing" option is nol, not no, and is
          the default.
                 Page 14:  The contc option continues a previously stopped
          cycle count and is not listed in ASREF.MAN.
                 Page 20:  The predefined constants for register addresses
          on the 6804 are A, X, & Y, not A, B, & C.