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General => The Campus => Topic started by: turboscrew on December 13, 2013, 05:21:30 PM

Title: system calls
Post by: turboscrew on December 13, 2013, 05:21:30 PM
I understand that 16-bit assembly is pretty much a thing in the past and 64-bit assembly is not yet very wide-spread, so
why is it so hard to find anything about 32-bit assembly system calls?
I mean like int 21h in 16-bit assembly.
Or is that same 16-bit system calls used in 32-bit assembly too?
Title: Re: system calls
Post by: dedndave on December 13, 2013, 07:19:06 PM
it's not hard at all
in fact, there's so much information, it's hard to comprehend all of it

here is one page from MSDN

http://msdn.microsoft.com/en-us/library/windows/desktop/aa365467%28v=vs.85%29.aspx (http://msdn.microsoft.com/en-us/library/windows/desktop/aa365467%28v=vs.85%29.aspx)

there are at least 10,000 similar pages - that's a conservative estimate
they have pages for win32 API functions, structures, constants, messages and notifications, etc
Title: Re: system calls
Post by: hutch-- on December 13, 2013, 09:51:14 PM
turbo,

Dave is right, system calls in 16 bit were done through mainly 2 sys files, in Win32 they are done through the Windows API functions. The difference is massive, a few hundred in DOS, over 12000 in Win32 and as a bonus, the Win32 function have far bigger range due to 32 bit memory addressing and they are generally a lot faster.