Library /sys$common/syshlp/patchhelp.hlb REPLACE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Use REPLACE to replace the contents of one or more locations with
 new  instructions  or data in terms of the current mode settings.
 Before performing the replacement, the REPLACE  command  confirms
 the contents of the specified locations.

 Replacing Instructions:
 _________ _____________
      When you replace instructions and the new instructions occupy more
      bytes in memory than the current instructions, the new instructions
      are moved to the patch area and PATCH generates branch instructions
      to maintain the program's logical flow of execution.  PATCH generates
      branch instructions for the REPLACE command the same way that it does
      for the INSERT command.  All unused bytes are filled with NOP instructions.

      If the patch area is used to accommodate the  new  contents,  the
      patch   area   string   descriptor  is  updated  to  reflect  the
      modifications.

 Replacing Data:
 _________ _____
      When you replace ASCII or numeric data, the number of replacement
      entries cannot exceed the number of existing entries.  This means,
      for example, that if you confirm the contents of six consecutive
      locations, you can replace the contents of only those six locations.
      If the number of replacement entries is less than the number of
      existing entries, the remaining locations are filled with zeros.

      In addition, PATCH truncates replacement entries if  they  exceed
      the  limit imposed on them by the current length mode.  For ASCII
      characters, the right-most characters are discarded.  For numeric
      data, the left-most digits are discarded.

 Calculating  Relative  Displacements  for  Branch   Instructions:
 ___________  ________  _____________  ___  ______   _____________
      PATCH  calculates  the  relative  displacements  for  the  branch
      instructions  it  generates   and   recalculates   the   relative
      displacements for all branch-type instructions moved to the patch
      area.  Instructions and data moved  to  the  patch  area  may  be
      referenced  by  instructions not affected by the move.  Note that
      PATCH does not recalculate the relative  displacement  values  in
      the unaffected instructions.

      Note also that if PATCH  moves  an  instruction  with  a  current
      address  defined  as a symbolic label, you must check and correct
      any references made to that label.  PATCH confirms  that  one  or
      more  consecutive  locations contain the contents supplied;  then
      replaces the contents with new contents.

 Format:

      REPLACE location = current-contents [,...]
      new-contents
              .
              .
              .

           Mode Qualifiers                 Default
           ____ __________                 _______

           /BYTE
           /WORD                           /LONG
           /LONG

           /OCTAL
           /DECIMAL                        /HEXADECIMAL
           /HEXADECIMAL

           /[NO]ASCII                      /NOASCII
           /[NO]INSTRUCTION                /NOINSTRUCTION
           /[NO]SYMBOLS                    /SYMBOLS

           /[NO]GLOBALS                    /NOGLOBALS
           /[NO]SCOPE                      /SCOPE

 Prompts:

 	LOC> location
 	OLD> current-contents
 	NEW> new-contents

  Additional Information (explode) :

• Parameters