How to disply Fractions

[Wh1t3gh0st]

Can someone show me how to display a Fraction entered by the user?
My problem is at prompt6.
This is my code so far...

TITLE MASM Template						(main.asm)

; Description: 
; Author:
; Assignment:
; Revision date:

INCLUDE Irvine32.inc
.data

firstNUM SDWORD ?
firstDEN SDWORD ?
secNUM SDWORD ?
secDEN SDWORD ?
prompt   BYTE "Please enter a two numerators and two denominators for two fractions.", 0
prompt2  BYTE "Please enter the first numerator: ", 0
prompt3  BYTE "Please enter the first denominator: ", 0
prompt4  BYTE "Please enter the second numerator: ", 0
prompt5  BYTE "Please enter the second denominator: ", 0
prompt6  BYTE "The first fraction you entered is: ", 0
               SDWORD  firstNum, "/", firstDEN, 0
prompt7  BYTE "The second fraction you entered is: ", 0
	    


.code
main PROC
	
	mov  edx, OFFSET prompt					;display prompt.
	call WriteString
	call CRLF
	mov  edx, OFFSET prompt2				;display prompt2.
	call WriteString						;allows user to enter an unsigned integer from the keyboard.								
	call ReadDec								mov firstNUM, eax
	mov edx, OFFSET prompt3
	call WriteString
	call ReadDec
	mov firstDEN, eax
	mov edx, OFFSET prompt4
	call WriteString
	call ReadDec
	mov secNUM, eax
	mov edx, OFFSET prompt5
	call WriteString
	call ReadDec
	mov secDEN, eax
	mov edx, OFFSET prompt6
	
	exit
main ENDP
END main

These all use the Irvine library, Thanks.

[Eri523]

To output the fraction, of course you need to convert both the numerator and denominator to decimal ASCII strings and then output those. Doesn't your library have a function for that? What needs to be done is the reverse of what ReadDec obviously does internally with a character string read in from the console and stored into an internal buffer. (It actually may do that on the fly without buffering as well, but that wouldn't change anything about the principle.)

In case your library doesn't have a binary-to-decimal conversion function, you can't find documentation on that process (which I consider to be unlikely) and/or just to quench your curiosity: Here's a thread that discusses exactly that topic: http://www.codeguru.com/forum/showthread.php?t=503267.

[Wh1t3gh0st]

Thanks, this is my resolved diplaying fraction after the last line, but for some reason it outputs a
+(number entered)/+(number entered).

                mov eax, firstNUM
	call writeInt
	mov al, 47
	call writeChar
	mov eax, firstDEN
	call writeInt
	call CRLF

Another question how would you reduce that fraction after multiplying two fractions? More code coming...

[Wh1t3gh0st]

This is my code after multiplying. Now I have a problem when I enter a negative number. The number results in a +0. Why and how to make it say -(Number). I am using the signed and imul, so I don't know what the problem is. Also I know that I need to use the cmp instruction when reducing just don't know how to completly do it.

TITLE MASM Template						(main.asm)

; Description: 
; Author:
; Assignment:
; Revision date:

INCLUDE Irvine32.inc
.data

firstNUM SDWORD ?
firstDEN SDWORD ?
secNUM SDWORD ?
secDEN SDWORD ?
newNUM SDWORD ?
newDEN SDWORD ?
prompt   BYTE "Please enter a two numerators and two denominators for two fractions.", 0
prompt2  BYTE "Please enter the first numerator: ", 0
prompt3  BYTE "Please enter the first denominator: ", 0
prompt4  BYTE "Please enter the second numerator: ", 0
prompt5  BYTE "Please enter the second denominator: ", 0
prompt6  BYTE "The first fraction you entered is: ", 0
prompt7  BYTE "The second fraction you entered is: ", 0
prompt8  BYTE "The result of multiplying the two fractions together is: ", 0

.code
main PROC
	
	mov  edx, OFFSET prompt						;display prompt.
	call WriteString
	call CRLF
	mov  edx, OFFSET prompt2					;display prompt2.
	call WriteString							;allows user to enter an unsigned integer from the keyboard.								
	call ReadDec								;allows the user's to get input and store it as an unsigned integer.
	mov firstNUM, eax
	mov edx, OFFSET prompt3
	call WriteString
	call ReadDec
	mov firstDEN, eax
	mov edx, OFFSET prompt4
	call WriteString
	call ReadDec
	mov secNUM, eax
	mov edx, OFFSET prompt5
	call WriteString
	call ReadDec
	mov secDEN, eax
	mov edx, OFFSET prompt6
	call WriteString
	mov eax, firstNUM
	call writeInt
	mov al, 47
	call writeChar
	mov eax, firstDEN
	call writeInt
	call CRLF
	mov edx, OFFSET prompt7
	call WriteString
	mov eax, secNUM
	call writeInt
	mov al, 47
	call writeChar
	mov eax, secDEN
	call writeInt 
	call CRLF
	mov eax, 0
	mov eax, firstNUM
	imul eax, secNUM
	mov newNUM, eax
	mov eax, 0
	mov eax, firstDEN
	imul eax, secDEN
	mov newDEN, eax
	mov edx, OFFSET prompt8
	call WriteString
	mov eax, newNUM
	call writeInt
	mov al, 47
	call writechar
	mov eax, newDEN
	call writeInt 
	call CRLF


	exit
main ENDP
END main

[Eri523]

Naturally, I have no idea of what's going on inside that library you use. Hopefully you have proper documentation on that library or its source code to aid you in finding out. But even without the library source code you may find out some things by stepping into the library code with your debugger. After all, in assembly language source code and object code aren't too far away from each other anyway. Perhaps all that you're observing actually is somehow by design of the library. And, of course, first thing you should do is make sure that you actually are passing correct data to the library functions - by debuging your own code.

One thing I can tell you, thogh: Yes, IMUL is the correct instruction for signed integer multiplication. But you probably already knew that anyway...

Another question how would you reduce that fraction after multiplying two fractions?

In assembly language that doesn't work differently than in any other language (except perhaps in some language specifically geared towards arithmetic/math that provides readily available instructions for that) - just like you would do it with an ordinary calculator - or with pencil and paper... Perhaps this is helpful in fortifying your background on fractional multiplication: http://en.wikipedia.org/wiki/Fractio...Multiplication