Fritz: All Fritz/All Fritz.zip/All Fritz/FILES/GAMEECTS/UNPROT4.LZH/FM.DOC

Text File | 1986-06-17 | 11KB | 227 lines

      DOCUMENTATION FOR FM.COM

            FM (for File Modify) is a little utility which allows you to
      easily edit files at the individual byte level.  It is especially
      useful in situations where one might use DEBUG to modify a byte in
      order to patch a program, to change the wording of messages in your
      programs which bother you (its search capabilities are useful for
      this) or to change color attributes in a program.

            The program is invoked by typing
                        fm FILESPEC
      If FILESPEC is of the form NAME.EXT, the program with that name in
      the current drive and directory will be loaded.  But fm supports
      other drives and full path names so if your default drive is A: and
      FM.COM is on the current drive or in the DOS search path, the
      command "fm B:\some directory\some filename" will work perfectly.


      KEYSTOKE COMMANDS

            A description of the most important keystrokes is displayed
      on the fm screen and the others are described in the help screen.
      The commands involve the function keys, cursor keypad, <TAB> and
      <ESCAPE>.

            The function keys have the following meanings
      F1:Help      F2:Search       F3:NOT USED       F4:NOT USED
      F5:Hex/Decimal toggle   F6:ASCII display toggle    F7:NOT USED
      F8:NOT USED      F9:Sector Save       F10:Sector Jump

            <ESCAPE> exits the program, <TAB> toggles the active cursor
      between the HEX and ASCII areas, the cursor arrow keys do the
      obvious things, <PGDN> reads the next sector, <CTRL-PGDN> the
      sector 5 sectors down and <PGUP> (resp. <CTRL-PGUP>) undo the
      actions of <PGDN> (resp. <CTRL-PGDN>). Home moves the cursor to the
      start of the active line and End to the end of the active line.


      THE FM DISPLAY

            Fm displays the file in "sectors" of 256 bytes each in 16
      lines with 16 bytes per line.  The line below the main display
      shows the file name, its date and time of creation or last update
      and the word HEX or ASCII indicating which part of the main display
      is active.  The <TAB> key toggles which is the active display and
      in addition to status line the active display is indicated by the
      block cursor.  Modifications are made on the active display as will
      be explained.

            The first column of numbers in the active display labels the
      lines by indicating the number of the first byte on the line.  In
      the default mode the numbers are in hexidecimal and appear in <..>.







      The <F5> key toggles to a decimal numbering of the lines.  The next
      16 columns of data show the HEX value of each byte, the 256
      possibilities for a byte corresponding to two HEX digits.  The next
      "column" gives the current sector number within the file and the
      number of sectors.  In default mode, these numbers are given in HEX
      but <F5> toggles not only the line numbers but also whether these
      numbers are given in HEX or decimal.  This same column also reports
      the current value of the <F5> HEX/decimal toggle.

            The right hand columns show the individual lines in ASCII
      form.  In the default mode, only "text characters" are shown with
      all non-text characters (ASCII numbers 0-31;129-256) are indicated
      by periods.  <F6> toggles to and from a mode where these characters
      are shown.  In the non-text mode, you can do a screen dump with
     <Shift PrtSc>

            A help screen is displayed if one hits <F1>.  You can exit the
      help screen by hitting <F1> or <ESCAPE>.



      MANEUVERING

            The <PGDN> and <PGUP> keys read the next and previous
      sectors.  Depressing the <CTRL> key while hitting these keys makes
      a change of 5 sectors.  If the <F10> key is depressed, you are
      prompted for a new sector number.  Responding <ENTER> will move you
      to the first sector (thus since unsuccessful searches will leave
      you in the last sector, you'll probably want to follow an
      unsuccessful search by the <F10>,<ENTER> combination).  Otherwise,
      a number should be entered and the program will jump to the
      appropriate sector.  If line numbers, etc are displayed in HEX
      (resp decimal), the sector number should be entered in HEX (resp.
      decimal).


      MODIFYING

            The whole point of FM is to change the file.  In the default
      mode, the block cursor is in the ASCII part of the screen.  The
      cursor can be moved with the arrow, home and end keys.  If a text
      character is struck, the character at the cursor is replaced by the
      character struck.  The <TAB> key toggles to the HEX display.
      Modification of the two HEX digit byte under the cursor is made by
      striking the appropriate keys.  Even if only one of the two digits
      needs to be changed, you must enter both of them.  If you have
      entered the first digit, it will change on the display and flash
      until the second digit is entered.  If any key other than 0-9,a-e
      is struck the byte returns to its initial value.

            Any changes made are indicated on both the HEX and ASCII
      display but they are only made in memory and NOT on the original
      file.  To make the changes in the original file, you must hit the







      <F9> key.  <F9> only saves the changes made in the currently active
      sector and not any changes made previously in other sectors.  If
      you try to exit the program or change the sector shown and you have
      made any unsaved changes, you are prompted to hit <F9> to save the
      changes if you wish.


      SEARCHING

            You can do a rudimentary search through the entire file
      FOLLOWING the cursor (not just the current sector).  Hitting the
      <F2> key prompts for a search string.  ASCII search strings will be
      searched regardless of whether the current active mode is ASCII or
      HEX.  To do a HEX search, proceed the byte with a "_".  Do not
      place quotes around _ or around search text.  You can search for
      multiple HEX bytes (so _41_61 will search for Aa) and ASCII and HEX
      can be mixed in the search string (so A_42C_44 will search for
      ABCD).


      MODIFYING FM

            One of the uses of fm is to modify itself if you wish to
      change some of the defaults in the program.  The twelve defaults
      which can be changed occur in sectors 1 (the first eight below) and
      3 in the form <relevant byte>-<FUNCTION>.  Thus, to change the
      color attribute for the ASCII text display, find the string ASCII.
      The byte immediately preceding it is 2D(hex) for - and the byte
      before that (which is 07 for grey on black) can be modified to
      change the display color.  For example, changing it to 1E will make
      that display as yellow on blue (on a color monitor).  The color
      code is the standard one set by IBM (but different from the BASIC
      and ANSI.SYS color codes), namely:
                0  black                4  red
                1  blue                 5  magenta
                2  green                6  brown (yellow)
                3  cyan                 7  grey (white)
      Adding 8(Hex) to these for the foreground color produces their
      "intense" version; intense brown is yellow and intense grey is
      white.  Adding 8 (Hex) to the background color causes the
      foreground to flash.  The first HEX digit determines the background
      and the second the foreground.  As indicated 1E (E=6+8 Hex) is
      yellow on blue while 9E would be flashing yellow on blue.

            Here are the other attributes which can be modified:

      LINE#  Color attributes for line number; default is 04=red on black
      HEX    Color attributes for the HEX display; default is 06=brown on black
      HEXED  Color attribute for the one changed HEX digit when editing
               in HEX mode and only one digit has been changed; default
               is F0=flashing black on white
      ACTIVE CURSOR  Color attributes of the active cursor; default is
               70=black on white.







      PASSIVE CURSOR Color attributes of the position of the cursor on
               the inactive screen (shadow cursor); default is 01=blue on black
      HELP SCREEN Color attributes of Help Screen; default is 74=red on white
      HELP BORDER Color attributes of Help Border; default is 1C=intense
               red on blue
      BOOT MODE The default is 00 which cause the ASCII screen to be the
               active one when the program is loaded.  Change it to 01 to
               make the HEX screen active upon program loading.
      BOOT DSTYLE  The default is 00 which cause the line numbers, etc.
               to appear in HEX upon loading.  Change to 01 to make
               decimal used upon loading.
      GRAPHICS  The default is 00 which causes only text characters to be
               displayed in the ASCII display when the program is loaded.
               Change to 01 to make all characters display upon loading.
      HEXID   The ASCII character used in a search string to preface a
               HEX specification.  The default is _ which has an ASCII
               code of 5F.  To change _ to $ for example change 5F to 24.

            The three items preceding HEXID concern the initial settings
      of the choices controlled by the <TAB>, <F5> and <F6> toggles.
      Some of the default attribute settings are chosen so the display is
      useful on a monochrome monitor and you may wish to change them if you
      run fm from a color monitor.


      DISCLAIMER

            The FM program is written and copyright by Doug Schaffer.
      These documentation is written by Barry Simon.  While the program
      has been used extensively and appears to be bug free, it is a
      powerful program and the responsibility for its use and any damages
      it might cause lies with the user.  Any comments can be sent to:
             Doug Schaffer                Barry Simon
             Caltech 1-78                 Caltech 253-37
             Pasadena, CA 91125           Pasadena, CA 91125

            While the program was written at Caltech, that
       institution bears no responsibility for the program.

           FM.COM may be freely distributed and used, but selling FM
       or bundling FM with software that is sold is not allowed.  Only
       unmodified copies of the original software may be  distributed.