Int 21 Fn 30  - Dos 2+ - Get Dos Version                                   [D]

   AH = 30h
---DOS 5+ ---
   AL = what to return in BH
       00h OEM number (as for DOS 2.0-4.0x)
       01h version flag

Return: AL = major version number (00h if DOS 1.x)
   AH = minor version number
   BL:CX = 24-bit user serial number (most versions do not use this)
---if DOS <5 or AL=00h---
   BH = MS-DOS OEM number (see #1082)
---if DOS 5+ and AL=01h---
   BH = version flag
       bit 3: DOS is in ROM
       other: reserved (0)

Notes: the OS/2 v1.x Compatibility Box returns major version 0Ah (10)
   the OS/2 v2.x Compatibility Box returns major version 14h (20)
   OS/2 Warp 3.0 Virtual DOS Machines report v20.30; Warp 4 VDMs report
     v20.40.
   the WindowsNT DOS box returns version 5.00, subject to SETVER
   DOS 4.01 and 4.02 identify themselves as version 4.00; use
     INT 21/AH=87h to distinguish between the original European MS-DOS 4.0
     and the later PC-DOS 4.0x and MS-DOS 4.0x
   IBM DOS 6.1 reports its version as 6.00; use the OEM number to
     distinguish between MS-DOS 6.00 and IBM DOS 6.1 (there was never an
     IBM DOS 6.0)
   MS-DOS 6.21 reports its version as 6.20; version 6.22 returns the
     correct value
   Windows95 returns version 7.00 (the underlying MS-DOS), as did the
     "Chicago" beta (reported in _Microsoft_Systems_Journal_,August 1994);
     Windows95 OSR2 returns version 7.10
   DR DOS 5.0 and 6.0 report version 3.31; Novell DOS 7 reports IBM v6.00,
     which some software displays as IBM DOS v6.10 (because of the version
     mismatch in true IBM DOS, as mentioned above).  The Novell DOS 7
     SETVER.EXE has an undocumented option /G x.y which sets the "global"
     DOS version returned by this function for all executables not given
     a specific version number in SETVER to major version x and minor
     version y.
   generic MS-DOS 3.30, Compaq MS-DOS 3.31, and others identify themselves
     as PC-DOS by returning OEM number 00h
   the version returned under DOS 4.0x may be modified by entries in
     the special program list (see #1348 at AH=52h); the version returned
     under DOS 5+ may be modified by SETVER--use AX=3306h to get the true
     version number

See Also: AX=3000h/BX=3000h,AX=3306h,AX=4452h,AH=87h,INT 15/AX=4900h

See Also: INT 2F/AX=122Fh,INT 2F/AX=4010h,INT 2F/AX=4A33h,INT 2F/AX=E002h

(Table 1082)
Values for DOS OEM number:
 00h   IBM
 01h   Compaq
 02h   MS Packaged Product
 04h   AT&T
 05h   ZDS (Zenith Electronics)
 06h   Hewlett-Packard
 07h   ZDS (Groupe Bull)
 0Dh   Packard-Bell
 16h   DEC
 23h   Olivetti
 28h   Texas Instruments
 29h   Toshiba
 33h   Novell (Windows/386 device IDs only)
 34h   MS Multimedia Systems (Windows/386 device IDs only)
 35h   MS Multimedia Systems (Windows/386 device IDs only)
 4Dh   Hewlett-Packard
 5Eh   RxDOS
 66h   PhysTechSoft (PTS-DOS)
 99h   General Software's Embedded DOS
 EEh   DR DOS
 EFh   Novell DOS
 FDh   FreeDOS
 FFh   Microsoft, Phoenix