PATCHING DEBUG TO WORK WITH DR-DOS

Most MS-DOS utilities verify the DOS version under which they are
being called, and will not run if an attempt is made to use them
with any other DOS version, whether MS- or DR-DOS.  To allow DEBUG
to be used with DR-DOS for the boot changing procedure, this
version check must be patched out.  The following procedure applies
to MS-DOS 5.0 and, of course must be executed under MS-DOS 5.0.

      Copy DEBUG.EXE to DEBUG.BIN.

      Execute DEBUG DEBUG.BIN.

      At the - prompt type U29A8, then press enter.

      This should be the result:
      
           xxxx:29A8  B430       MOV   AH,30
           xxxx:29AA  CD21       INT   21
           xxxx:29AC  3D0500     CMP   AX,0005
           xxxx:29AF  7503       JNZ   29B4
      (the xx's represent values that will vary between systems,
      and are unimportant here.)
       
      If you don't see this display, then the version of DOS 5.0
      you have is not the same as mine.  In that case, you will have
      to use the "s" command to find the string B4 30 CD 21 and make
      the changes below at the offset location that you find.

      Assuming your display agrees with that above, continue by   
      typing at the - prompt E29AF, then press enter.

      Type in the number 90, press spacebar, type 90 again, then
      press enter.

      At the - prompt type U29A8, then press enter.

      This should be the result:

           xxxx:29A8  B430       MOV   AH,30
           xxxx:29AA  CD21       INT   21
           xxxx:29AC  3D0500     CMP   AX,0005
	   xxxx:29AF  90         NOP
	   xxxx:29B0  90         NOP
      
      If that's what you get, type W, enter, then type Q, enter.

      Now rename your original DEBUG.EXE to something else, in case 
      there is a problem, and rename DEBUG.BIN to DEBUG.EXE.  Put 
      the patched DEBUG back into the MSDOS directory.