OK, here it is: patches for LIST Plus v7.4A that will switch the
alt-X and X exit functions with each other.
  First, the 'legalese'....  these patches are ONLY for the LIST.COM
dated 8-8/9-90 found in LIST74A.ZIP (the LIST PLUS version).  These
patches were only tested on this version.  No attempt was made to
modify the other smaller versions of LIST (listr.com and lists.com).
The patches will NOT work with these other two programs.  Please make
a backup copy of the file before proceeding.
  In the default mode, X will exit LIST by clearing the screen before
stopping at the DOS prompt, and alt-X will exit LIST with the screen
prior to the LIST call displayed.
  To reverse these two operations, do the following:

    debug list.com
    -e 0431 08
    -e 0451 08
    -e 0486 12
    -w
    -q

  For the record, the following table shows the original entries
in the WHAT table:
   keyboard   debug        original
   key        address      contents
   X          0431          12
   x          0451          12
   alt-X      0436          08

  Note that the docs found in LIST74A.ZIP show the starting address
of the WHAT table as 0393, whereas it is really 03D9.
  Thanks to Vern Buerg for a GREAT program.

PS, the attached file XALTX.PAT can be used to run these patches
    "automatically" if you don't want to type them in.
    Just do:   DEBUG < XALTX.PAT   with LIST.COM in the same directory
    as the patch file.