mov al, VerOrOEMFlag ;01h = version flag, 00h = OEM number
mov ah, 30h ;Get Version Number
int 21h
mov MajorV, al ;major version number (05h for version 5.0)
mov MinorV, ah ;minor version number (00h for version 5.0)
mov VerOrOEM, bh ;version flag or OEM number
mov byte ptr [UserNum+2], bl ;bl:cx is 24-bit user serial number
mov word ptr [UserNum], cx
Get Version Number (Function 30h) returns the MS-DOS version number set by the setver command for the program. The function also returns either the MS-DOS version flag or the original-equipment-manufacturer (OEM) number.
VerOrOEMFlag
Specifies whether the function returns the version flag or the OEM number in the BH register. It can be one of the following values:
| Value | Number |
| 00h | The OEM number |
| 01h | The version flag |
The AX, BX, and CX registers contain the following information:
| Register | Contents |
| AL | The major version number for the program—for example, 03h for version 3.31, 05h for version 5.0. |
| AH | The minor version number for the program—for example, 1Fh for version 3.31, 00h for version 5.0. |
| BH | Either the OEM number or the version flag. In the latter case, if the version flag is set to DOSINROM (08h), MS-DOS runs in ROM; otherwise, MS-DOS runs in RAM. All other bits are reserved and set to zero. |
| BL:CX | The 24-bit user serial number. The user serial number is OEM-dependent. If not used, the number is set to zero. |
This function returns the MS-DOS version number set by the setver command. This version number can differ from the actual MS-DOS version number returned by Get MS-DOS Version (Function 3306h).
For more information about the setver command, see the Microsoft MS-DOS User's Guide and Reference.
Function 3306h Get MS-DOS Version