HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

                      INT 21,30 - Get DOS Version Number

       AH = 30h

       on return:
       AL = major version number (2-5)
       AH = minor version number (in hundredths decimal)
       BH = FF  indicates MS-DOS, only if OEM vendor chooses to identify
          = 00  indicates PC-DOS
       BL:CX = 24 bit OEM serial number if BH is FF

       - for an example DOS version 2.1 returns AL=2 and AH=10
       - DOS versions prior to DOS 2.0 return zero in AH and AL
       - DOS version 4.0 and 4.1 usually return the same value of 4.00
       - the OEM serial number is a rarity, though some older OEM DOS
         versions implemented this feature
       - the OS/2 compatibility box returns 10.10 for OS/2 1.1, 10.20
         for OS/2 1.2, etc...
       - when testing for version, a specific test can often cause your
         code to not work in following versions of DOS.  It is often better
         to test for a version number greater or equal to the minimum rather
         than a specific version number where possible
       - see DOS Versions

Esc or Alt-X to exit int 21,30 Home/PgUp/PgDn/End ←↑↓→
Converted to HTML in 2006 by Timo Bingmann