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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
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Esc or Alt-X to exit |
int 21,30 |
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