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> Main > strange include in format mz (newbie only for asm lang) |
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DOS386 21 Aug 2007, 07:15
Code: include 'subfunc.inc' ; only works here Strange  - and secret ? 
Have a look at COMDEMO & EXEDEMO examples, and here: http://board.flatassembler.net/topic.php?t=6735 
No need to deal with segments (unlike in MA$M) or include any junk _________________ Bug Nr.: 12345 Title: Hello World program compiles to 100 KB !!! Status: Closed: NOT a Bug |
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21 Aug 2007, 07:15 |
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muratselim 21 Aug 2007, 07:28
i haven't seen any include directive in the example other than simulating
win executables format... can you give a small sample mz which uses include directive in the begining i need it to modular codding BTW, thanks for fast response |
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21 Aug 2007, 07:28 |
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muratselim 21 Aug 2007, 07:57
Code: Write_String: ; Writes string from DS:SI until character #0 is met mov ah, 0xE xor bh, bh mov bl, 0x7 .nextchar: lodsb or al,al jz .return int 10h jmp .nextchar .return: ret if that helps... |
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21 Aug 2007, 07:57 |
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ChrisLeslie 21 Aug 2007, 08:07
You can put your include file earlier on but just be sure that the contents do not get executed when it should not. If you are calling a subroutine from it, then an unexpected ret will crash the program. You could try jumping over it by puting a jump instruction at the beginning of the include file and a label at the end to jump to. But there is nothing wrong with leaving it at the end of the source for simple programs.
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21 Aug 2007, 08:07 |
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muratselim 21 Aug 2007, 08:13
Code: format MZ ;define the type of program stack 200h ;define the stack size jmp Start include 'subfunc.inc' entry cod:Start segment dat ;define the data segment Message db "Hello World" ;the data segment cod Start: ;start the program mov ax, dat ;move the segment of Message to the accumulator mov dx, Message ;move the offset of Message to displacement register mov ds, ax ;move segment of Message to data segment register call Write_String ;mov ah, 09h ;move 9 to the accumulator ;int 21h ;perform interrupt 33 mov ah, 00h ;move 0 to the accumulator int 16h ;perform interrupt 22 mov ax, 4c00h ;move the close program directive to the accumulator int 21h ;perform interrupt 33 this doesnt work. where i can put it? Last edited by muratselim on 21 Aug 2007, 08:58; edited 1 time in total |
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21 Aug 2007, 08:13 |
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muratselim 21 Aug 2007, 08:23
Code: format MZ ;define the type of program stack 200h ;define the stack size ; right place here entry cod:Start segment dat ;define the data segment Message db "Hello World" ;the data segment cod Start: ;start the program jmp main include 'subfunc.inc' main: mov ax, dat ;move the segment of Message to the accumulator mov dx, Message ;move the offset of Message to displacement register mov ds, ax ;move segment of Message to data segment register call Write_String ;mov ah, 09h ;move 9 to the accumulator ;int 21h ;perform interrupt 33 mov ah, 00h ;move 0 to the accumulator int 16h ;perform interrupt 22 mov ax, 4c00h ;move the close program directive to the accumulator int 21h ;perform interrupt 33 reosanabely okey its working but not good proggramming practice... thanks for all response if you have better solution please post it[/code] |
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21 Aug 2007, 08:23 |
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daluca 30 Aug 2007, 16:42
Hi muratselim: sorry for the late reply.
if you want to include the file at the begining,first must realize that it has to be put inside some segment,if you put it in another segment rather than your cod segment then you must do a far call(I haven't use dos for a time so i don't remember how you do that) but if you want to put it at the begining of your cod segment the right would be: Code: format MZ stack 200h entry cod:Start segment dat Message db "Hello World" segment cod include 'subfunc.inc' Start: mov ax, dat mov dx, Message mov ds, ax call Write_String mov ah, 00h int 16h mov ax, 4c00h int 21h but if you do it only prints garbage. the reason? you design your Write_String function to write the string pointed by ds:si but in your code you move Message to dx not to si,so if you change: Code:
mov dx, Message
for: Code:
mov si, Message
it works now. but... if the SI wasn't initialized properly in the other examples,why puting the function at the end or jumping over it worked? well it looks like at program startup SI holds your program entry point: then leaving your program entry point at the begining of the cod segment makes the program entry = 0000 and since the offset of the Message string is at offset 0000 (in the dat segment) SI luckily point to the right place. but if you include your 'subfunc.inc' at the begining of the segment then the entry point is displaced and that is why it prints garbage. and 2 more things: you forgot to put a 0 at the end of the string,in this case it dosn't matter since the string will be follow by a bunch of zeros but is a good proggramming practice. in your Write_string function you are assumming tha the direction flag is cleared what may not be the case always so it may be a good thing to include a cld in the initialization part. regards. |
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30 Aug 2007, 16:42 |
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