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Oeiuwq Faith Blog OpenSource Porfolio

otya128/winevdm

16-bit Windows (Windows 1.x, 2.x, 3.0, 3.1, etc.) on 64-bit Windows
Source code at GitHub https://github.com/otya128/winevdm
otya128/winevdm.json
{
  "createdAt": "2015-09-22T13:40:08Z",
  "defaultBranch": "master",
  "description": "16-bit Windows (Windows 1.x, 2.x, 3.0, 3.1, etc.) on 64-bit Windows",
  "fullName": "otya128/winevdm",
  "homepage": "",
  "language": "C",
  "name": "winevdm",
  "pushedAt": "2026-01-02T02:12:54Z",
  "stargazersCount": 3191,
  "topics": [
    "win16"
  ],
  "updatedAt": "2026-03-18T21:41:32Z",
  "url": "https://github.com/otya128/winevdm"
}

winevdm on 64-bit Windows

Section titled “winevdm on 64-bit Windows”

![screenshot]!(screenshot.PNG)

Download stable version

Download latest version (unstable)

16-bit Windows (Windows 1.x, 2.x, 3.0, 3.1, etc.) on 64-bit Windows

An altered version of winevdm (a 16-bit Windows emulator), ported to 64-bit Windows.

How to run

Section titled “How to run”

How to install

Section titled “How to install”
  • Download or compile
  • Run “install” shortcut or right-click on install.inf and select “Install”
  • You can execute Win16 binaries directly!

If the registry is initialized by Windows Update, perform the above procedure again.

You can uninstall it by running uninstall.reg.

Configuration

Section titled “Configuration”

See [otvdm.ini]!(otvdm.ini).

How to compile(Visual Studio)

Section titled “How to compile(Visual Studio)”
  • Install Visual Studio 2017
  • Edit PropertySheet.props
  • Compile

How to compile(cmake)

Section titled “How to compile(cmake)”
Terminal window
git clone https://github.com/otya128/winevdm.git
cd winevdm
mkdir build
cd build
cmake ..
make

How does it work?

Section titled “How does it work?”

This program contains the following items

  • CPU Emulator
    • 64-bit Windows cannot modify LDT(NtSetInformationProcess(,ProcessLdtInformation,,) always returns error)
  • wine based Win16->Win32 conversion codes: 
    BOOL16 WINAPI DestroyWindow16( HWND16 hwnd )
    {
        return DestroyWindow( WIN_Handle32(hwnd) );
    }
    Relay routines from 16-bit to 32-bit are autogenerated by convspec 
    53  pascal -ret16 DestroyWindow(word) DestroyWindow16
  • DOS emulation for Win16
  • 16-bit <=> native HANDLE conversion
  • Fix compatibility problems, fix compatibility problems

install.inf

Section titled “install.inf”

When 64-bit Windows detects a 16-bit installer, it has a mechanism to start an alternative installer which is not 16-bit. This program uses it.

WINDOWS directory redirection

Section titled “WINDOWS directory redirection”

Some Win16 programs try to save their settings in %WINDIR%<filename>.ini

In recent Windows, it is not allowed to save to %WINDIR%, so it redirects.

winevdm

Section titled “winevdm”
Terminal window
winevdm.exe [--app-name app.exe] command line
winevdm.exe CALC.EXE

It can also run DOS executables (DOS emulator-like). You can set the DOS version with the VDMDOSVER environment variable.

DOS emulation is incomplete and it is recommended to use DOSBox or MS-DOS Player.