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From: brianc@cognos.UUCP (Brian Campbell)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How do I patch my PC-DOS 3.1 for control-U and -W support
Message-ID: <418@cognos.UUCP>
Date: Fri, 6-Mar-87 13:02:52 EST
Article-I.D.: cognos.418
Posted: Fri Mar  6 13:02:52 1987
Date-Received: Tue, 10-Mar-87 20:42:45 EST
References: <162@parcvax.Xerox.COM>
Organization: Cognos Inc., Ottawa, Canada
Lines: 41

in article <162@parcvax.Xerox.COM!, burton@parcvax.UUCP says:
! Posted: Sat Feb 28 20:27:58 1987
! 
! There has been much mail on the topic of patching various DOS'es to enable
! control-U and control-W support.  No one has provided specific instructions
! at the byte-location level of detail.
! 
! I was able to compare the IBMDOS.COM file in PC-DOS 3.1 with the corresponding
! files for Xerox MS-DOS 3.1 and Wyse MS-DOS 3.1.  No two files are alike, but
! the latter two both support control-U and -W.
! 
! Presumably, I would have to use a disk sector editor, such as Norton, because
! I have to be sure not to move the location of IBMDOS.COM on the disk.
! 
! Any suggestions.  Please post directly to the net, for the benefit of all.
! 
! Phil Burton
! Xerox Corp.

It was I who originally posted the query, and also posted the fix for PC-DOS
3.10 and 3.20.  You will need a disk sector editor, or DEBUG utility to make
the patch.  I'm including the patch again since I've mailed it out about 8 or
9 times since originally posting it.

I really wouldn't expect Xerox's and/or Wyse's IBMDOS to be identical to the
PC-DOS version -- but I rather expect that portions will be.

Here's the patch to enable Ctrl-U and Ctrl-W in DOS 3.20 (patch is applied to
system file IBMDOS.COM).  Turns out the code is identical the same in 3.10 and
3.20, just different locations.  In 3.10 the patch starts at offset 1DB9, in
3.20 at offset 1E96 (based at 0100 as in DEBUG).  The code fragment is:

   3C 17	CMP AL,17
   74 5E	JZ  $+60	(original 90 90		NOP NOP)
   3C 15	CMP AL,15
   74 51	JZ $+53		(original 90 90		NOP NOP)

If you're using a disk sector editor, you can search for the following
HEXADECIMAL text:  3C 17 90 90 3C 15 90 90, then replace it as indicated.
 
Brian Campbell