4DOS and MS-DOS 5.0


   (Copyright 1991, JP Software Inc., All Rights Reserved. Published by
   JP Software Inc., P.O. Box 1470, E. Arlington, MA 02174 USA, (617)
   646-3975. Released June 11, 1991.)


4DOS Compatible with DOS 5

   As you've probably heard, the newest release of MS-DOS, version 5.0,
   was announced today, and may already be on the shelves at your
   favorite computer store.  DOS 5 contains a number of important
   enhancements, but few of them are in the area of command processing.
   4DOS continues to offer a vast improvement over the standard DOS
   command processor, so you can continue to enjoy the improved power,
   flexibility, and control provided by 4DOS while using this latest
   version of DOS.

   We've done extensive testing with 4DOS and DOS 5, and we're pleased
   to be able to tell you that they're fully compatible.  You can
   install 4DOS under DOS 5 as you have under earlier versions of DOS,
   and continue to use all the features, power, and flexibility that
   4DOS provides.  4DOS versions 3.02a and 3.03 are fully compatible
   with DOS 5; the same is almost certainly true of 4DOS 3.0 and 3.01,
   but we have not specifically tested these older versions.

   These notes tell you how to use the current release of 4DOS with
   DOS 5.  A major new release of 4DOS, to be released later this
   summer, will add many new features and improvements, take advantage
   of new capabilities offered by DOS 5, and adjust some 4DOS command
   switches to conform more closely to those used in DOS 5.  (The term
   "DOS 5", as we use it here, refers to MS-DOS 5.0; for information on
   using 4DOS with DR-DOS 5.0 see the COMPAT.DOC file that came with
   your copy of 4DOS.)


Installing 4DOS with DOS 5

   The first thing you'll notice if you install DOS 5 from the retail
   upgrade package is that 4DOS doesn't get loaded.  That's because DOS
   5's SETUP installation program converts your SHELL= line in
   CONFIG.SYS to load COMMAND.COM.  To fix this, just save a copy of
   CONFIG.SYS before installing DOS 5, and use your editor to move the
   old 4DOS SHELL= line back to your new CONFIG.SYS.  If you haven't
   saved a copy of CONFIG.SYS, use the one SETUP saves on your DOS 5
   Uninstall disk as CONFIG.DAT.

   You may also find that 4DOS's HELP appears not to work properly
   under DOS 5, whether you invoke it with the HELP command or the F1
   key.  This is probably because your DOS directory is in the PATH
   before your 4DOS directory, so 4DOS finds DOS's HELP.EXE instead of
   its own.  To fix this, rearrange your PATH so the 4DOS directory is
   before the DOS directory.  If you don't want to rearrange the PATH,
   you can set up a 4HELP environment variable to tell 4DOS where to
   find the HELP.EXE program when F1 is pressed, and an alias to do the
   same for the HELP command.  If your 4DOS HELP.EXE program is in the
   directory C:\4DOS, and DOS's HELP.EXE program is in C:\DOS, the
   appropriate commands to add to AUTOEXEC would be:

          set 4help=c:\4dos\help.exe
          alias help c:\4dos\help.exe
          alias doshelp c:\dos\help.exe

   The second alias allows you to use the command DOSHELP if you want to
   access DOS 5's HELP.  In the next release of 4DOS we will change the
   name of the HELP program to 4HELP.EXE to avoid conflicts with DOS 5's
   HELP as well as many other software packages that use the name
   HELP.EXE for their help systems.

   Once you've taken care of these minor glitches, you can install and run
   4DOS normally under DOS 5.


4DOS and DOS 5 Upper Memory Block Support

   4DOS uses Upper Memory Blocks (UMBs) to support the /U and /E:nnnnU
   startup switches; see your 4DOS manual for the details.  UMBs can be
   provided by most 386 memory managers (e.g.  386MAX or QEMM) and by
   some 286 products (e.g. MOVE'EM or QRAM, with appropriate hardware).

   Under MS-DOS 4 and below, UMBs are managed by your memory manager or
   an XMS driver.  DOS 5 introduces a new approach where UMBs can be
   managed by DOS itself, if you use the DOS=UMB directive in
   CONFIG.SYS.  4DOS currently uses UMBs allocated by your memory
   manager or XMS driver, but can't access UMBs managed by DOS 5.  If
   you have a memory manager with UMB support you'll probably find that
   it provides more flexible UMB management than DOS 5, and continue to
   use it; in this case 4DOS's /U and /E:nnnnU options will work just
   fine.  If you do allow DOS 5 to manage your UMBs, the 4DOS version 3
   /U and /E:nnnnU switches will not work, eliminating the memory
   savings they normally provide.  Our upcoming release will fully
   support the use of UMBs managed by DOS 5.

   DOS 5 adds one new internal command which uses UMBs, LOADHIGH (or LH),
   which we've also added to the next release of 4DOS.  LOADHIGH works only
   with DOS 5 UMB management, so if you don't choose to use DOS 5 to manage
   UMBs, you can skip this tip.  However you can access DOS 5's LOADHIGH
   command right now with two aliases:

   	alias loadhigh command /c loadhigh
   	alias lh loadhigh

   These aliases assume that COMMAND.COM is in a directory that's on your
   PATH.  If you use them and the LOADHIGH operation is unsuccesful, you
   may leave a "hole" in lower memory.  This is not usually harmful, but
   can waste memory.


DOS=HIGH and 4DOS

   DOS 5 also includes a DOS=HIGH option to load the kernel of DOS into
   memory above 1MB.  This option is unrelated to UMBs, and works properly
   with 4DOS.  The memory savings it achieves will be added to any you've
   already generated with 4DOS.


ANSI Driver Detection under DOS 5

   On some systems, once DOS 5 is installed you may see strings like
   "[2J" on the screen when you try to do a CLS command, or see similar
   problems with COLOR.  This is because, under DOS 5, 4DOS may think an
   ANSI driver is loaded when in fact you aren't using one.  To get
   around the problem use the command SETDOS /A2 to tell 4DOS to assume
   an ANSI driver is not installed. Place this command in the 4START
   file (see page 25 of your 4DOS manual) to make it effective in both
   primary and secondary shells. SETDOS /A2 is available in 4DOS 3.03
   and above, but is not listed in the version 3.03 documentation.


DOS External Command Error Messages

   MS-DOS versions 4 and 5 include an unusual mechanism for displaying
   errors from external DOS commands like XCOPY, FORMAT, or DISKCOPY.
   These commands use the command processor to retrieve their error
   messages; if the messages aren't found they display cryptic messages
   like "Parse error 3" or "Extended error 7".  4DOS does not currently
   support this mechanism, but will support it in the next release, due
   out later this summer.  In most cases these errors are generated by
   simple typographical errors which are almost immediately obvious. If
   you see error messages like this while using MS-DOS 4 or 5 with 4DOS,
   and the cause isn't obvious, check the attached list of error codes
   to interpret the message.


4DOS and the DOS 5 Shell

   Finally, DOS 5 contains an entirely rewritten DOS shell (DOSSHELL.EXE). 
   4DOS works fine with DOSSHELL.  If you have COMSPEC set properly for
   4DOS and use Shift+F9 to get a command prompt from DOSSHELL, you'll get
   4DOS. However if you use the built-in "MS-DOS Command Prompt" menu
   choice, you'll get COMMAND.COM.  To change this, put the cursor on this
   menu choice and then select File Properties from the menu, and change
   the command line to load 4DOS.COM (with its full path) instead of
   COMMAND.COM.