Q80783: Determining the Version of MS-DOS from a Windows App
Article: Q80783
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s):
Keyword(s): kb16bitonly
Last Modified: 06-NOV-1999
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1
-------------------------------------------------------------------------------
SUMMARY
=======
There are at least three ways for an application developed for Windows version
3.x to determine the version of MS-DOS that is running on the system. Both the
first and second methods require placing a few lines of inline assembler code
into the application. The second method requires MS- DOS version 5.0. The third
method requires changing the GetVersion() function prototype in the WINDOWS.H
header file distributed with the Microsoft Windows SDK version 3.0 (this change
is not necessary if the Microsoft Windows SDK version 3.1 is being used).
Even though it is necessary to modify the Windows 3.0 header file, the third
method is the most removed from the hardware and can be considered the most
portable. The other two methods assume an underlying Intel 80x86 architecture
(or emulation).
MORE INFORMATION
================
Method 1
--------
This method requires only a few lines of inline assembler code and a call to the
DOS3Call() function. The following code fragment demonstrates this technique:
VOID FAR PASCAL DOS3Call(VOID); // Use instead of INT 21h
int nMajor; // MS-DOS major version
int nMinor; // MS-DOS minor version, revision
int nOEMNumber; // OEM serial number
static char szUserMsg[80]; // holds user message
_asm
{
mov ax, 0x3000 ; Get MS-DOS version
call DOS3Call
mov nMajor, al ; Save major number
mov nMinor, ah ; Save minor version number
mov nOEMNumber, bh ; Save OEM Serial number
}
wsprintf(szUserMsg,
"Running on MS-DOS %d.%d OEM Serial Number %d",
nMajor, nMinor, nOEMNumber);
MessageBox(hWnd, szUserMsg, "MS-DOS Version", MB_OK);
Method 2
--------
This method requires only a few lines of inline assembler code and a call to the
DOS3Call() function. Additionally, it requires that MS-DOS version 5.0 is
running on the system. While this function does not report the OEM serial
number, it does report whether MS-DOS is in ROM or in HMA (the High Memory
Area). Also the MS-DOS version returned by this method is unaffected by the
SETVER command. The following code fragment demonstrates this technique:
#define DOSINROM 0x08
#define DOSINHMA 0x10
int nMajor = 0;
int nMinor = 0;
int nRevision = 0;
int nDOSFlag = 0;
static char msg[120];
_asm
{
mov ax, 0x3306 ; Get MS-DOS version
call DOS3Call
mov nMajor, bl ; Save major number
mov nMinor, bh ; Save minor version number
mov nRevision, dl ; Revision num in low 3 bits
mov nDOSFlag, dh ; MS-DOS version flags
}
wsprintf(msg,
"Running on MS-DOS %s %s version %d.%d revision %d ",
(LPSTR) (nDOSFlag & DOSINROM ? "in ROM " : ""),
(LPSTR) (nDOSFlag & DOSINHMA ? "in HMA " : ""),
nMajor, nMinor, (nRevision & 0x03));
MessageBox(hWnd, msg, "MS-DOS Version", MB_OK);
Important Note for Methods 1 and 2
----------------------------------
The DOS3Call() function must be prototyped. In assembly language, the appropriate
prototype is as follows:
extrn DOS3CALL: far
Use the DOS3Call() fucntion instead of making a direct call to MS-DOS INT 21h.
The DOS3Call() function runs a little faster than the equivalent INT 21h call
under Windows and it ensures that the interrupt will be handled correctly under
Windows.
Also note that the use of FAR and PASCAL in the definition of DOS3Call() requires
use of WINDOWS.H, since these macros are defined there.
Method 3
--------
The last method involves making a slight modification to the Windows SDK version
3.0 header file, WINDOWS.H. To retrieve the MS-DOS version, change the return
type in the function prototype of the GetVersion function call from a WORD to a
DWORD. The modified prototype should resemble the following:
DWORD FAR PASCAL GetVersion(void);
NOTE: It is not necessary to make the above change to the version of the
WINDOWS.H file included with the Windows SDK version 3.1.
The following code fragment demonstrates how to use the GetVersion() function to
display both the MS-DOS version and the Windows version numbers:
DWORD dwVersion;
char szUserMsg[80];
dwVersion = GetVersion();
wsprintf(szUserMsg,
"Window version %d.%d. MS-DOS version %d.%d",
LOBYTE(LOWORD(dwVersion)), HIBYTE(LOWORD(dwVersion)),
HIBYTE(HIWORD(dwVersion)), LOBYTE(HIWORD(dwVersion)));
MessageBox(hWnd, szUserMsg, "GetVersion", MB_OK);
Additional query words: 3.00 3.10
======================================================================
Keywords : kb16bitonly
Technology : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version : WINDOWS:3.0,3.1
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.