need help in adding numbers and displaying them
in [ASM]
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From: lonetunes on 30 Aug 2005 03:04 i need help in adding numbers in assembly language using masm. i want to know how to add decimal numbers in assembly language and then display it. i dont know the procedure for displaying numbers. i know the procedure to display characters is as follows: mov dx, offset message mov ah, 9h ; int 21h ; do i use a different interrupt to display decimal number need help urgently
From: Dirk Wolfgang Glomp on 30 Aug 2005 05:51 lonetunes(a)yahoo.com schrieb: > i need help in adding numbers in assembly language using masm. Simply use the "add dest,source" instruction. Example: "add eax, ebx". > i want > to know how to add decimal numbers in assembly language and then > display it. i dont know the procedure for displaying numbers. > > i know the procedure to display characters is as follows: > > > mov dx, offset message > mov ah, 9h ; > int 21h ; > > do i use a different interrupt to display decimal number No, there is no softint to display a different output. You must selfconvert the value in ASCII-digits. A 32bit number are max. 10 decimal ASCIIs. To split the values in parts, just divide the value by 1000000000, and the following by 10. Example: mov ecx, 1000000000 xor edx, edx ; set edx to zero(faster than "mov edx, 0") div ecx ; eax divide by ecx ; result in eax ASCII-numbers begin at 30h, so it is easy to add 30h to every splited byte. Example: "add al, 30h". Dirk
From: JGCASEY on 30 Aug 2005 06:41 lonetunes(a)yahoo.com wrote: > i need help in adding numbers in assembly > language using masm. i want to know how to > add decimal numbers in assembly language > and then display it. i dont know the > procedure for displaying numbers. > > > i know the procedure to display characters > is as follows: > > > mov dx, offset message > mov ah, 9h ; > int 21h ; > > > do i use a different interrupt to display > decimal number > > > need help urgently Why is it urgent I wonder. What is your tutorial material. Google for assembler tutorials. You don't mention what kind of decimal numbers? How many bits? Signed numbers? Floating point? They aren't binary coded decimal numbers are they? Assuming unsigned 16 bit numbers you add them like this, Put your values in, CLC ;clear carry flag MOV AX,34 ;ax = 34 MOV CX,60 ;cx = 60 ADD AX,CX ;ax = ax + cx You must test for no carry in case the result is bigger than 16 bits. JNC OK There is no interrupt to display decimal numbers. You have to convert the number, which is the binary format, into a string of asc characters which you can than print. If you keep dividing a number by 10 the remainder will be a single digit value 0 to 9 which you convert into its asc code by adding 48 (30h). ;***********************************************************; ;CONVERTS NUMBER IN AX TO ASC STRING POINTED TO BY DI ; ;IN: AX = number ; ;OUT: DI -> buffer (-> means points to) ; ;***********************************************************; putnum PROC push ax push dx ;save regs note we are NOT saving DI push cx ;to make it easy to concatenate two push bx ;answers together mov bx,10 ;bx = base 10 sub cx,cx ;clear cx = number of digits pnl1: sub dx,dx ;clear most significant word for DIV div bx ;divide by 10 add dl,'0' ;remainder in dl make it an ASCII character push dx ;and save it on the stack inc cx ;update the digit count or ax,ax ;is the quotient 0? jnz pnl1 ;now we have all the digits on the stack pnl2: pop ax ;get last digit first stosb ;save it in output buffer loop pnl2 ;cx=cx-1:If cx<>0 then goto pnl2 sub al,al ;al = 0 stosb ;make it a null terminated string pop bx ;restore registers pop cx pop dx pop ax ret putnum ENDP This above example produces a null terminated string. I am not sure but the interrupt above might require this be changed to a $ character?
From: randyhyde@earthlink.net on 30 Aug 2005 11:18 lonetunes(a)yahoo.com wrote: > i need help in adding numbers in assembly language using masm. i want > to know how to add decimal numbers in assembly language and then > display it. i dont know the procedure for displaying numbers. > > i know the procedure to display characters is as follows: > > > mov dx, offset message > mov ah, 9h ; > int 21h ; > > do i use a different interrupt to display decimal number > > need help urgently You might want to take a look at the UCR Standard Library for 80x86 assembly language programmers. It contains lots of wonderful routines for printing numbers and other things. You can find a copy here, with lots of other MASM resources: http://webster.cs.ucr.edu/AsmTools/MASM/MASMLibs.html http://webster.cs.ucr.edu/AsmTools/MASM/index.html And you might have your instructor check out this: http://webster.cs.ucr.edu/ As it provides lots of resources for learning assembly language programming. Cheers, Randy Hyde
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