Have trouble with this code

[etow]

Hi

I am having trouble with the following code below:

.686 ; create 32 bit code
    Option CaseMap :none                    ; case sensitive

Include   \masm32\macros\macros.asm       ; MASM support macros

  ; -----------------------------------------------------------------
  ; include files that have MASM format prototypes for function calls
  ; -----------------------------------------------------------------
Include   \masm32\include\masm32rt.inc

  ; ------------------------------------------------
  ; Library files that have definitions for function
  ; exports and tested reliable prebuilt code.
  ; ------------------------------------------------
IncludeLib   \masm32\lib\msvcrt.lib

.Const
Two = 2

.Code

start:
;<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
   Call Main
   inkey        ; pause the screen while waiting for user to press any key
                ; to continue
    exit
;<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Main Proc
   Local Number:DWord
   Local numAmt:DWord
   ; Number is the number being mulitipled
                ; numAmt is the number of times it is multiplied
                ;--------------------------------------------

    Mov numAmt, sval(input("Enter a positive integer for the number of times 2 to be multiplied by itself : "))

    Mov Ebx, Two
    Mov Ecx, 1      ; while loop counter

    print chr$(13, 10)        ; a return key space will be outputted to the screen
    print chr$(" ")           ; a space will be outputted to the screen
    print str$(Two)           ; 2 will be outputted to the screen

   .While Ecx <= numAmt
     Mov Eax, Ebx
     IMul Number
     Mov Ebx, Eax
     print chr$(" * ")       ; * 2 will be outputted to the screen as many times according to user
     print str$(Two)
     Add Ecx, 1
    .EndW

    print chr$(" = ")         ; =  will be outputted to the screen
    print str$(Ebx), 13, 10   ; the result of the multiplication will be
                              ; outputted to the screen
    print chr$(13, 10)        ; a return key space will be outputted to the screen

    Ret
Main EndP

End start

-------------------------------------------------------------------------

I can not get the while loop to work above because
if I enter 1 it displays "2 = 2" and other numbers the same result is displayed.
It supposed to say 2 * 2 = 4 when 1 is entered for input by user
and 2 * 2 * 2 * 2 = 16 when 3 is entered for input by user

I need much help.

Thanks

[jdoe]

etow,

Don't give up   ::)

1) You forgot to set the initial value of Number
2) ECX is a register that needs to be preserved and in the loop ECX get lost after the "print" call

For registers preservation...

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Main Proc uses ebx esi


Initial value of Number and ECX replacement by ESI

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   Mov Number, Two
   Mov Ebx, Two
   Mov Esi, 1      ; while loop counter


The loop

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.While Esi <= numAmt
    ...
    Add Esi, 1
.EndW


[etow]

Hi here is my final code in zip file

For product of 2's by mulitplication:



[attachment deleted by admin]

[etow]

Here is the the algorithm for product of twos:

Code Select Expand



     maxNumberAmount = (positive integer >= 1)  ; number of times the while loop executes
     numberMultiply = 2  ; the accumulation of the product of twos
     counter = 1     ; number of times to multiply numberMultiply by

     print(" 2 ")             
     Do While (counter <= maxNumberAmount)
        numberMultiply = numberMultiply * counter
        print(" * 2 ")
        counter = counter + 1           
     Loop

     print (" = ")
     print(" 2^")
     print(counter)
     print(" = ")
     print(numberMultiply)


[etow]

Hi

I modify my final code to do base two to powers from 0 to 29 in the zip file:

[attachment deleted by admin]