hello everybody!

the things may be too basic for you but :) however not for me..

the functions of interrupts are moved into AH, are all of them are done so or there are some other
conditions? and when lower and when higher order registers are used? what happens if a function is moved into AL? please tell me about using them a little, some things that can help me to understand using them
:confused: thx!
Posted on 2003-03-10 13:43:47 by applecin
The hardware doesn't care.

The software (OS) cares, big time.

DOS expects function codes to be in AH for INT 21h services. No matter what you do, it will look at AH to determine what to do. The usage of the other registers are determined by the function, as defined by DOS.

The other INTs may follow the same convention, maybe not. Get a DOS reference, such as Ralf's interrupt list.

As this is a Win32 forum, some versions of Windows will not handle INT 21h in native 32-bit mode. You can create a DOS program and run it in a pseudo-DOS environment under Windows, but you won't be able to integrate this knowledge into a "Win32" program.
Posted on 2003-03-10 14:48:24 by tenkey