Simtel MSDOS 1992 December/simtel1292_SIMTEL_1292_Walnut_Creek.iso/msdos/sysutl/memres41.arc/RESDEL.DOC

Text File | 1988-07-24 | 11KB | 253 lines

                             Ed Jordan 70357,2162
                                  RESDEL.EXE
                           Version 4.1  - July 1988

    1.  tablev.exe<cr> - enter from DOS with no ram resident utilities
    2.  resdel<cr>     - to get help message
    3.  resdel \r<cr>  - remove all ram residents and replace vectors
    4.  resdel \n<cr>  - n = 1 to 9; remove one or more utilities

    This  program  replaces earlier versions.  The table fix-up routine has
    been rewritten.  Some vectors were not properly located by the  earlier
    versions.

    This  program  has  several helpful enhancements.  The program will now
    display the vector numbers which are being  replaced  from  the  backup
    copy  of  the  table.   In  addition,  the  name of the memory resident
    program will be displayed.  I have also taken the liberty of  including
    a  separate  program in this archive which I did not write.  MAP.COM is
    also on CompuServe and is in the public domain.   I  do  not  know  how
    MAP.COM  works.   This  version will allow the user to remove more than
    one utility without replacing the entire vector table.  As noted below,
    there  can still be problems if vectors are redirected by more than one
    utility in a cascade fashion. Be careful or you will have  to  use  the
    red switch.

    To  delete  ram  resident  utilities  this the program requires that an
    accurate copy of the default vector table be made as a file on the disk
    where  it  can be located.  I wrote the program to look for this vector
    table file in the root directory of drive (A).  Note: DEBUG.COM  cannot
    be  used  to  make  a copy of the vector table because it redirects the
    vectors just like a memory resident utility does.

    The "\R" mode copies the vector table from the file (VECTOR.TBL) to the
    1024  bytes  of  memory  at  0:0.   Then  the  program  deallocates the
    environment blocks and program segment prefix (PSP) blocks from the end
    of  DOS to the beginning of the program itself.  This is all of the RAM
    residents in low memory.  If a resident installs itself in high  memory
    and then readjusts the size of the system memory, this program will not
    work and it will be incompatible.

    The "\n" (n = 1 to 9) causes successive memory blocks lower  in  memory
    than  RESDEL.EXE  itself to be removed.  The program locates all of the
    blocks between the parent program (DOS) and itself by reading the chain
    of  memory  blocks.   If  there  are  no intervening blocks between the
    parent program and RESDEL.EXE, no action is taken.  Otherwise, the next
    lower block corresponding to a PSP and its environment block, if found,
    are deleted.  The vector table information present  in  low  memory  is
    searched  for  references to the code segment of the deallocated block.
    These vectors are replaced with the original values.  In this way,  the
    resident  utility  is  effectively  removed  and  the  memory freed for
    further use.  The program then  recycles  until  the  specified  number
    (1-9) of utilities are removed.

    A  brief  help  message is displayed if no entry is made on the command
    line or if an incorrect command is given.  If "\0" is entered, only the


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                                resdel.exe


    title  message  is  displayed.  No action is taken regarding the vector
    table or the utilities in low memory.

    GETTING STARTED:
    Boot your system  from  its  basic  configuration  without  any  memory
    resident  utilities  in  place.   This should be the DOS itself running
    with the correct number of files and buffers  and  any  device  drivers
    that you want to have installed.

    Then  run  TABLEV.EXE  from  the  DOS  command line.  This program will
    create a file called VECTOR.TBL in the current  directory.   Copy  this
    file  to  the root directory of drive "A:".  This is the default vector
    table that RESDEL.EXE looks for.  The instructions below show how  this
    default location can be changed.

    Once this is done, you are ready to load your memory resident utilities
    and then remove them when desired by running RESDEL.EXE  from  the  DOS
    command  line.   RESDEL.EXE will not work as a child process to another
    program other than DOS itself.  For example, it will not run as a child
    process under DEBUG.COM.  The program thinks that the parent segment is
    DOS.  It is really DEBUG instead and you will get an error message.

    Caution: Be very careful if the vectors are redirected more than  once.
    Utilities  often redirect a vector that a previously loaded utility has
    already redirected.  In this  situation,  you  will  probably  have  to
    replace  the  entire vector table and start over or keep a special copy
    of the table for a particular situation.  Instead of running TABLEV.EXE
    with clean memory, run it with the utility already loaded that you want
    to keep after a subsequent utility is  removed.   This  will  give  the
    program  the  correct  vector  to  replace when you delete a subsequent
    utility that also redirects the vector.  Otherwise the program replaces
    the vector for a clean memory and the remaining memory resident utility
    then cannot function properly.  You may get system lock-up.  You  could
    have several copies of VECTOR.TBL stored under different names and then
    copied to the  name  VECTOR.TBL  in  a  batch  file  prior  to  running
    RESDEL.EXE.

    I  will  try to keep the bugs fixed if I know about them.  I wrote this
    program on an IBM PC model 5150 which has a 1982 ROM upgrade and  a  20
    meg.  hard  drive.   I am including the source code with the program so
    that you may adjust the code for your particular situation if  this  is
    needed.

    A  helpful program called MAP.COM (by Dorn W. Stickle) is included with
    this archive.  This program will give you a memory map which will  tell
    you  which  vectors point to which programs.  Using MAP you can see the
    vectors assigned to each program as you load successive utilities.

    RIGHTS:
    This  program  is  contributed  to  the  public  domain.   It  may   be
    distributed.  No charge is to be made for these programs although costs
    for magnetic media  may  be  recuperated.   No  warranty  expressed  or
    otherwise  is  provided  with  this  software.   It  is provided as is.
    Defects may be present which  can  prevent  it  from  working  on  your
    particular computer.


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                                resdel.exe



    This group of programs is included:
                                  TABLEV.ASM version 1a
                                  TABLEV.EXE
                                  RESDEL.DOC
                                  RESDEL.EXE
                                  RESDEL.ASM version 4.1
                                  PATCH.BAT
                                  PATCH.INS

    For  those  who do not have an assembler and want to change the default
    drive for VECTOR.TBL:

                  ren resdel.exe resdel.123<cr>
                  debug resdel.123<cr>
                  ecs:06fb<cr>
                  41.43<cr> ( to make drive C )
                  w<cr>
                  q<cr>
                  ren resdel.123 resdel.exe<cr>

    A short batch file  which  provides  this  patch  is  included  in  the
    archive.  Enter "PATCH" to patch the program for drive C.  You may edit
    PATCH.INS to change this patch for a different drive.  Note: VECTOR.TBL
    can  be located in a subdirectory.  Supply the correct path name in the
    PATCH.INS file that is provided.  The path and program name must end in
    a  binary  zero  (asciiz format).  A correct example is provided in the
    PATCH.INS file.  In addition, it is possible  to  change  the  name  of
    VECTOR.TBL  using  the  same  patch and supplying a different name.  Be
    sure that you keep the archive file in a safe place so that you do  not
    accidentally ruin the only copy of these programs that you have.

    To  run  PATCH.BAT  you  will  need  to have DEBUG.COM in your path and
    RESDEL.EXE will need to be in the current directory.

    TABLEV.EXE has been revised.   A  user  of  a  TANDY  1000  experienced
    difficulty  using  the  earlier  version.   I  hope that the change has
    corrected the problem.  DEBUG.COM cannot be used to make a copy of  the
    vector  table  because it redirects vectors just like a memory resident
    utility.

    RESDEL.EXE ERROR MESSAGES:

    ** Please do not try to delete DOS
    The program has not found any memory resident utilities between  itself
    in  memory  and  the segment of its parent program.  This is DOS if the
    program is run from the DOS command line.

    ** Unrecognized command
    There are two command line switches.  "\n"  and  "\r"   where  n  is  a
    number between 1 and 9.  See the text above.

    ** Insufficient memory
    The  program  allocates  1024 bytes to be used as a buffer to store the
    default memory table.  This program should run in 64K of memory.


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                                resdel.exe



    ** Warning: Vector not located
    Should the program try to remove a utility from memory and yet not find
    a  vector  in  the table that points to that memory block, this message
    will be displayed.  A memory block is removed but vectors have not been
    redirected.  I have seen this message when a utility has redirected all
    of the vectors that a previously loaded utility had captured.

    ** Error freeing allocated memory block
    An error occurred when DOS tried to return a block  of  memory  to  the
    system pool.

    ** VECTOR.TBL not found.
    The  default  copy  of  the  vector  table  could  not be located.  Run
    TABLEV.EXE from the command line with DOS in its  clean  configuration.
    No memory resident utilities installed.  See text above.

    ** Warning: SHARE.EXE installed
       Do you wish to proceed? (Y/N)
    SHARE.EXE  changes  some of DOS below COMMAND.COM in low memory.  It is
    best to reboot if you see  this  message.   To  continue  may  redirect
    interrupt  2F  which  is  used by SHARE.EXE but it does not correct the
    other  changes.   Your  system  may  not  function  correctly  in  this
    situation.  Note: interrupt 2F is supported by DOS 3.0

































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