
 1. About DOSX
 
 HX's DOSX is a replacement for the Windows 3.1 DOSX.  It's purpose is to
 use HX's DPMI host HDPMI16 to run Windows 3.1 or WfW 3.11 in standard mode
 with DOS boxes available. This has one big benefit: HDPMI16 doesn't grab
 all of the extended memory, thus allowing other DPMI applications to be
 run in DOS boxes opened inside windows. Furthermore, the windows DOSX
 cannot use more than 512 MB memory, while HDPMI16 has no restriction
 in this regard.
 
 
 2. Installation
 
 - Copy HX's DOSX.EXE to the Win3.1 system directory. It's a good idea
   to first make a backup copy of the original DOSX.EXE.


 3. Running DOSX.EXE
 
 Since some Win16 applications may cause a floating-point exception in HDPMI,
 it is recommended to first set environment variable HDPMI:
 
  SET HDPMI=32768

 Most applications will run without this setting, but some important ones
 will need it (Netscape Navigator, ...).
 Then run windows in standard mode by typing in the windows directory:
 
   WIN /S
    
 Please note: although DOSX.EXE could be launched directly (type
 SYSTEM\DOSX in the windows directory), this method won't run WSWAP.EXE,
 which is required for task switching in windows standard mode. So if
 windows is started this way one cannot open a DOS box.


 4. Known Problems
 
 - WfW 3.11's WIN.COM claims that this version cannot be run in standard
   mode. To run it nevertheless in this mode, copy WIN.COM, WSWAP.EXE and
   DSWAP.EXE from Windows 3.1 to the corresponding WfW 3.11 directories and
   start it with "WIN /S".

 - if FreeDOS is used with Windows 3.1, the system might crash when opening
   a DOS box. As I found out it may help to load SHARE.COM, a special version
   for FreeDOS. Then this problem seems to vanish. I'm not the maintainer
   of FreeDOS's share tool, but you may download it from
      http://www.japheth.de/Download/share.zip
   This version has a bug fixed which caused MS office applications not to
   work on Windows 3.1. Please note that the FreeDOS' SHARE doesn't work
   with MS-DOS.

 - the Windows 3.1 taskswitcher WSWAP.EXE is not aware of XMS v3 (an API to
   access more than 64 MB of extended memory). This causes problems if an
   application (including HDPMI) is using XMS v3 functions:
   þ on machines with 64 MB memory or less HDPMI is not compatible with
     WSWAP.EXE - unless you set environment variable HDPMI=64, which 
     instructs HDPMI to not use XMS v3 functions at all.
   þ on machines with more than 64 MB memory environment variable HDPMI=64
     should *not* be set. HDPMI will then use XMS v3 functions to allocate
     memory and not interfere with WSWAP.EXE. However, the first 64 MB of
     XMS memory will be grabbed by WSWAP.EXE and not be accessible by HDPMI.
   

 5. How does DOSX work?
 
 The windows startup procedure in standard mode is:
 
  - WIN.COM is started (by the user, with commandline parameter "/S") 
  - SYSTEM\WSWAP.EXE is launched by WIN.COM
  - SYSTEM\DOSX.EXE is launched by SYSTEM\WSWAP.EXE
  - SYSTEM\KRNL386.EXE is launched by SYSTEM\DOSX.EXE
  
 HX's DOSX is a simple DOS real-mode application, unlike the Windows DOSX,
 which is the DPMI host used for standard mode. HX's DOSX will first start
 HDPMI16.EXE if no DPMI server is found, then load and run KRNL386.EXE as
 it is done by the original DOSX.
 
 
 6. Copyright
 
 HX's DOSX is free to use for any purpose. Source and binary are released
 to public domain.
 
 Japheth
 
