flat assembler
Message board for the users of flat assembler.
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comrade 02 Jun 2009, 00:54
They probably call int 10h inside their int 21h handler. Kinda like routines call other subroutines. Remember software interrupts are similar to a function call mechanism. Except in modern software they also bring an environment change (user-mode to kernel-mode). On DOS they are pretty much like a subroutine call
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LocoDelAssembly 02 Jun 2009, 02:41
If Int21 calls Int29 for on-screen printing then:
DOS 2+ - FAST CONSOLE OUTPUT wrote: AL = character to display Ref: http://www.ctyme.com/intr/rb-4124.htm |
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GhostXoPCorp 02 Jun 2009, 04:05
thanks for the reply, what i thought is that t used its own screen drivers, if so that would of anwered another question, the other question was why is command.com so big? in asm shouldnt it be smaller? or are there things that are background and cant be noticed, maybe its the buffers? one more question (getting annoying, sorry) what is a stacks over flow and i know it has a connection with the keyboard, when key mash i get the little error screen, i promise these are all the questions i have left for dos
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rCX 02 Jun 2009, 16:38
Which DOS are you using? In FreeDOS, command.com is 66945bytes.
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GhostXoPCorp 02 Jun 2009, 16:45
no, the original ms-dos, but i know why free dos is so big, it doesnt use assembly as a main for programming, but i have seen somewhere some one built an os with more functionallity than dos and much smaller, does dos use assembly, or is there many background things that arents noticed, like for security of anything else?
_________________ Oh that divide overflow. Just jumps out of the bushes every time to scare the day lights out of me. |
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