
 1. About

  This package is intended to support development of 32-bit DOS extended
  applications with HX (support for 16-bit is contained in the HXDV16
  package). It contains:

   þ libraries with HX's Win32 emulation in COFF format
   þ samples in assembly, C, Pascal, Basic, Cobol
   þ support files for debugging with Open Watcom's WD
   þ some helper tools

  Due to HX's Win32 emulation approach it is very well possible to create
  binaries running under HX without using any of the things mentioned above.
  See 4. for more details.


 2. Installation

  First make sure the HX runtime (HXRT) is already installed. Then extract
  HXDEV.ZIP in the same directory where the HX runtime has been unpacked.


 3. Compatible Compilers and Assemblers

  The following compilers/assemblers for 32-bit have been tested to create
  binaries compatible with HX:

                       Compiler + Linker may
   Name                run under HX as well
   -----------------------------------------------
   JWasm, Masm, PoAsm     yes
   Fasm                   yes
   Nasm, Yasm (Win32)     yes
   Wasm                   yes
   Tasm                   yes
   LZAsm (Win32)          yes
   Visual C++ (MS)        yes
   Borland C++            yes
   Digital Mars C++       yes
   MinGW C++              yes
   Pelles C               yes
   CC386 (Win32)          yes
   LCC-Win32              no
   Open Watcom (Win32)    yes
   Delphi                 yes
   Virtual Pascal (Win32) yes
   Free Pascal (Win32)    yes
   Pascal Pro             yes
   PowerBasic             no (?) 
   Free Basic (Win32)     yes
   MF Object Cobol        no
   XDS Modula 2           yes


 4. How to make Binaries running with HX

  The following file formats are/were supported by HX:

  HX Name    Type  API     Loader   supp. Dlls Comment
 ----------------------------------------------------------------------
  Win32-PE   PE    Win32   DPMILD32  yes       standard Win32 console
  DOS-PE     PE    DOS     DPMILD32  yes
  DOS-PEt    PE    DOS     DOS       no        with stub LOADPE.BIN

  DOS-MZ     MZ    DOS     DOS       no        (virtually) obsolete
  DOS-NE     NE    DOS     DPMILD32  yes       obsolete
 (Win32-MZ   MZ    Win32   DOS       no        abandoned)
 (Win32-NE   NE    Win32   DPMILD32  yes       abandoned)

  a) Win32-PE

   The easiest way to make HX binaries is to create Win32 console applications.
  This format is natively supported by many development tools. As far as HX
  is concerned all one has to ensure is that only Win32 functions emulated
  by HX are used. 
   A possible disadvantage may be that to be loaded in DOS it will need at
  least DKRNL32.DLL, HX's Kernel32 emulation, and very often additional dlls.
  HX's PE loader DPMILD32 might also be needed as external binary, but
  optionally it can be linked statically into the binary as MZ stub.

  b) DOS-PE and DOS-PEt

   These binaries will always be loaded as DOS applications, since the "PE"
  signature is hidden from the OS. Besides that it is pretty much up to the
  developer what is linked into the binary or what is kept in external
  modules. See "Comparison of Stubs" below for details about the stubs
  available in HXDEV for the DOS PE format.
   HX's Win32 emulation can optionally be used by DOS-PEs. If dynamic
  linking is supported (true for all stubs except LOADPEx.BIN), DKRNL32.DLL
  can be loaded at runtime. But usually it's a better idea to create a
  stand-alone binary with the Win32 emulation code linked statically.

  c) DOS-MZ

   The DOS-MZ format is still supported, but compared to DOS-PEt there is
  virtually no advantage anymore. To create such binaries the 
  compiler/assembler must support the OMF object format. This limits the 
  working set of tools significantly. Most assemblers will do, as will 
  Digital Mars C/C++, LADSoft CC386 and Open Watcom C/C++. 

  d) DOS-NE

  The DOS-NE format is obsolete, because it has no advantages compared to
  the other formats.

  e) Win32-MZ/Win32-NE

  These formats are no longer supported, the OMF libraries containing the 
  Win32 emulation for the segmented memory model have been removed. The
  DOS-PEt format can fully replace these formats and it has some significant 
  advantages.


 5. Comparison of Stubs supplied with HX

 The linker will usually add a MZ stub to HX PE binaries. There are five
 available, and each has its pros and cons:

               size   supports  PE-loader    HDPMI     cwsdpmi
  Name         in kB    dlls?   included?  included?  compatible?
 ----------------------------------------------------------------------
  DPMIST32.BIN  0.5      yes       no         no         no
  LOADPE.BIN    1.25      no      yes         no         yes
  LOADPEX.BIN   35        no      yes        yes         yes
  DPMILD32.BIN  14       yes      yes         no         no
  HDLD32.BIN    48       yes      yes        yes         no

  DPMIST32.BIN: this is HX's standard stub, supplied with HXRT. It's tiny,
  but will need to load external binaries, DPMILD32.EXE and - if no DPMI
  host is found - HDPMI32.EXE. 

  LOADPE.BIN: this is a simple PE loader. The application will run in a
  zero-based flat memory model, but dynamic linking (dlls) isn't supported,
  and the binary must not contain references to external modules (imports).
  HDPMI32.EXE is loaded if no DPMI host is found.

  LOADPEX.BIN: this is LOADPE.BIN with HDPMI included, allowing to create
  stand-alone DOS-PE binaries - without support for dynamic linking.

  DPMILD32.BIN: this virtually is HX's PE loader DPMILD32. Compared with
  DPMIST32.BIN load time will be reduced since the loader hasn't to be
  searched and is available at once. HDPMI32.EXE is loaded if no DPMI host
  is found.

  HDLD32.BIN: this stub contains HX's DPMI host and PE loader (HDPMI32
  and DPMILD32), so a stand-alone DOS-PE binary will be the result -
  with support for dynamic linking.


 6. Debugging

  DPMILD32 offers some options to support debugging of PE binaries. View 
  Doc\DPMILD32.TXT for details. Especially useful IMO is the protection of
  address range 0-3FFh, which may allow to detect NULL pointer usage.
  This protection is achieved by using "expand down" segments. Regretably
  the MS Windows 9x DPMI hosts are *not* compatible with such segments.

  Since HX V1.30 Open Watcom's debugger WD may be used to debug all types
  of HX binaries, at least on assembly level. View OWSupp\Readme.txt for
  details.


 7. Hints

  Since HX V2 all functions required by Turbo Vision 32 are available,
  so Win32 TUA applications written with this library should run with HX.
  Tested with TV version 2.0.3 from http://tvision.sourceforge.net/.


 8. Files OverView

  þ Bin\PatchPE.EXE: tool to change PE apps to PX apps. View PatchPE.txt
    for more details. PatchPE is a 16-bit DOS application. If there's no
    possibility to run such binaries, tool PESTUB ( with cmdline option
    -x ) provides the same functionality and may be used instead. PESTUB
    is contained in HXRT.

  þ Bin\PatchNE.EXE: tool to set the application type of NE applications.
    View PatchNE.txt for more details.

  þ Bin\NTLFNHLP.DLL: implements LFN translation service for NT platforms.
    Not required for Win32 emulation, since this code is statically 
    linked into DKRNL32.DLL. But it may be useful for applications using
    the DOS API only.

  þ Bin\SHDPMI.EXE: tool to protect parts of DOS memory and system tables
    in protected mode. This may detect programming errors, since Win32
    apps will find a similiar environment when running on NT platforms.
    Should be used together with environment variable DPMILDR=2048, which
    additionally protects linear memory 0-3FFh. Works with HDPMI only.

  þ Bin\SHDPMIR.EXE: DOS tsr program. Only required if SHDPMI is to 
    be called with option -d. Allows DOS memory 1000h-FFFFh to be
    protected by SHDPMI.

  þ Bin\*.BIN: MZ stubs to be added to PE binaries.

  þ OWSUPP subdirectory: trap files to support creating and debugging
    32bit extended DOS apps with Open Watcom. View readme.txt in this
    subdirectory for more details.

  þ Samples subdirectory: source code samples showing how to create
    apps with HX DOS extender in ASM, C, Pascal, PowerBasic and Object 
    Cobol. View readme.txt in this subdirectory for more details.

  þ Include subdirectory: some ASM includes for Win32 API and DPMI.
    They are sufficient for creating the samples and assembling HX itself.
    For a full set of Win32 includes get Win32Inc or MASM32.

  þ LIB subdirectory: Libraries in MS-COFF format. These may be used
    to link PE binaries.

    - dkrnl32.lib, dadvapi.lib, dgdi32.lib, duser32.lib: import libraries
      for references to KERNEL32, ADVAPI32, GDI32 and USER32 dlls. Using 
      these libraries is optional, the standard Win32 libs (kernel32.lib,
      user32.lib, ...) will do as well. They have just one advantage: if a
      function not emulated by HX's Win32 layer is used, a linker error will
      occur.
    - dkrnl32s.lib, dadvapis.lib, dgdi32s.lib, duser32s.lib: libraries
      containing HX's Win32 emulation as static code. Feeding the linker
      with those libs will result in a (stand-alone) DOS-PE, not a Win32-PE.
    - imphlp.lib: this helper library is needed if the Win32 emulation is
      linked statically to the binary. It emulates the PE IAT entries
      (__imp__xxx) for kernel32 and user32. Some linkers are capable to add
      such entries automatically, then this lib is superfluous.
    - libc32s.lib: a static, simple CRT library. Might create very small
      binaries. MS VC compatible.
    - crtdll.lib: library to dynamically link with CRTDLL.DLL. CRTDLL.DLL
      is a C runtime dll included in all versions of MS Windows.
    - vesa32s.lib: statically link VESA functions.
    - vesa32.lib: link to VESA32.DLL.

  þ LIBOMF subdirectory: Libraries and modules in OMF format. These are
    intended to be used by OMF linkers when creating 32bit MZ binaries.

    - jmppm32.obj, jmppm32.lib, dmysrvr.obj, dmymove.obj, loadsrvr.obj: 
      object modules for MZ file format support.

  þ DOC subdirectory: some help texts for various files: 

    - MZSupp.txt:   description of HX's MZ file format support.
    - DpmiLd16.txt: description of the 16-bit NE file loader.
    - PatchPE.txt:  description of tool PatchPE.
    - PatchNE.txt:  description of tool PatchNE.


 9. History

  13.10.2025, V2.23: OW WD trap helper files v1.6
  24.03.2025, V2.22: stub LOADPERO.BIN added; OW WD trap helper files v1.5.
  08.02.2024, V2.21: -
  28.01.2023, V2.20: -
  30.03.2022, V2.19: Src\MZSUPP\InitPM.asm added.
                     EDITPE.EXE, PESTUB.EXE and DPMILD32.BIN added.
  07/28/2018, V2.18: -
  12/18/2012, V2.17: OW WD trap helper file HXHELP.EXE updated to v1.3.
  11/16/2009, V2.16: InitW32x.obj added.
  01/20/2009, V2.15: All samples for Masm changed to use JWasm instead of
                     Masm. Masm can be used optionally.
  03/02/2008, V2.14: Added stubs LOADPE.BIN/LOADPEX.BIN.
                     Removed several libraries for segmented memory model
                     in OMF format: static Win32 emulation and libc32.
                     Samples rearranged and extended to show usage of
                     LOADPE(X).BIN stubs and how to link the Win32 emulation
                     code statically to the binary.
                     Support for Open Watcom updated.
  01/11/2008, V2.13: stand-alone binaries supported, for both PE and MZ.
  07/15/2007, V2.12: DPMILD32 no longer makes assumptions about the FS
                     register, it is not used. Be sure there is no mix
                     of HXRT and HXDEV. They must both be either < v2.12
                     or >= v2.12.
                     THREAD sample added.
  03/15/2007, V2.11: HX's PE loader DPMILD32 included as a MZ stub.
                     Support for DJGPP added (crt0hx.o, djgpp.ld, ldfix.exe,
                     Src/djgpp and Sample/djgpp).
                     lib\dcrt32s.lib renamed to lib\libc32s.lib.
  12/14/2006, V2.10: -
  10/15/2006, V2.9:  -
  09/14/2006, V2.8:  -
  08/15/2006, V2.7:  -
  07/17/2006, V2.6.1:bugfix: writing to the console did not work for
                     non-flat code (HX MZ binaries)
  07/15/2006, V2.6:  The samples in OWSUPP have been moved to Samples
                     subdirectory (where they logically belong).
  06/14/2006, V2.5:  creating NE applications simplified.
                     LADSoft linker VALX added to TestOMF.
                     bugfix: previous version contained a nonworking HX.TRP
                     for Open Watcom WD.
  05/15/2006, V2.4:  -
  05/02/2006, V2.3:  -
  04/21/2006, V2.2:  -
  04/04/2006, V2.1:  -
  03/18/2006, V2.0:  tools SHDPMI.EXE/SHDPMIR.EXE added.
                     TestOMF moved to subdirectory SRC.
  02/06/2006, V1.43: -
  01/22/2006, V1.42: CRT startup modules for Open Watcom V1.4 added.
  01/02/2006, V1.41: -
  12/20/2005, V1.40: -
  12/07/2005, V1.39: -
  11/24/2005, V1.38: -
  11/18/2005, V1.37: -
  11/07/2005, V1.36: -
  10/24/2005, V1.35: Vesa32.dll moved to HXRT.
  09/29/2005, V1.34: Samples ShowBMP and TextOut added. DDDRAW.DLL moved to
                     HXRT.
  09/19/2005, V1.33: -
  09/05/2005, V1.32: -
  08/28/2005, V1.31: Support for Open Watcom improved. Source level 
                     debugging for HX MZ binaries with WD now possible.
                     Bin\DPMIST32.EXE deleted.
  08/14/2005, V1.30: HX Trap file for Open Watcom's WD extended so it may
                     now be used to debug all types of HX binaries.
                     New option for DPMILD32 to protect linear address range
                     0-3FFh to detect NULL pointer usage.
  08/06/2005, V1.29: Open Watcom support has been extended so the OW Dos386
                     CRT modules may be used for HX binaries. This makes HX
                     compatible with WAT-TCP, which simplifies creating
                     internet applications with HX ;-). 
  08/01/2005, V1.28: -
  07/06/2005, V1.23: sample dynload.mak added
                     hellone.mak added to show how to create a 32bit
                     NE application. 
                     Tool patchNE.exe added.
  06/23/2005, V1.21: NTLFNHLP.DLL added
  06/14/2005, V1.20: C++ sample using VESA32 added.
                     VESA32 V1.2, DDDRAW V1.1.
                     Libraries split into Lib and LibOMF.
  06/07/2005, V1.19: PLASMAxx dual-mode 2D-graphics samples added.
                     DDDRAW.DLL added.
  06/06/2005, V1.18: VESA32.DLL + samples using VESA graphics added.
  05/22/2005, V1.16: -
  02/06/2005, V1.13: -
  10/27/2004, V1.10.1: Bugfix: dkrnl32s.lib had a bug causing MZ executables
                     using Win32 API to crash on NT platforms.
  10/24/2004, V1.10: DPMI TSR sample added.
                     Sample for Pascal Pro added.
                     Sample for LZAsm added.
  10/06/2004, V1.8:  MicroFocus Object Cobol sample added.
  10/03/2004, V1.7:  Delphi, NASM and PowerBasic samples added.
  09/11/2004, V1.3:  Adjustments required because HDPMI now scans the
                     command line. 
  09/03/2004, V1.2:  C runtime libraries added.
  08/31/2004, V1.1:  MZSupp directory deleted, is now in HXSRC package.
  08/27/2004, V1.0:  first version. Previously this was in DPMILDXX package.


 10. License

  The HX DOS extender is freeware. Copyright Japheth 1996-2020. HX can be 
  used for any purpose. The HX development package can be freely distributed.

  Japheth

