Using MASM (Microsoft Macro Assembler)

This page discusses how to use MASM, and is based on Getting Started with MASM and Visual Studio 2026 from Kip Irvine:
  1. Download and Install Microsoft Visual Studio Community.
    2. Visual Studio Community is a fully-featured, extensible, free IDE (Integrated Development Environment) for creating modern applications for Android, iOS, Windows, as well as web applications and cloud services.



  2. Enable MASM in a C++ Project if Needed.
    3. Using the Microsoft Macro Assembler (MASM) in Visual Studio requires enabling specialized build rules for your project. Because Visual Studio is primarily a C++ IDE, MASM is included within the C++ workload. If you cannot find MASM in Visual Studio Community, it is likely because the workload is missing or the project has not been configured to recognize assembly files. Take the following steps:

    1. Open the Visual Studio Installer.

    2. Select on your Visual Studio Community installation.


    3. Check the box for .


  3. Download and Install the Three Zip Files from GitHub project page:
    4. The page includes the following three zip files:

    • : Code examples and required libraries

    • : Sample 32-bit Visual Studio 2026 project, configured for assembly language

    • : Sample 64-bit Visual Studio 2026 project, configured for assembly language

    Unzip the and put the files in the folder :


  4. Create a Project.
    5. Copy the project folder from Irvine to a new project folder like :



    Replace the file by :



    Arithmetic.asm 
    COMMENT !
  Calculate an arithmetic mean, (1+2+3+...+n) / n:
  
  1. Read the n.
  2. Calculate the arithmetic series, 1+2+3+...+n.
  3. Divide the sum by n.
  4. Display the quotient, the arithmetic mean.

  Require Irvine32.inc and Irvine32.lib (Kip Irvine's library)
!

INCLUDE Irvine32.inc   ; Include Irvine32 macros and procedures

.data
  prompt1  BYTE "Enter the n: ", 0
  prompt2  BYTE "The arithmetic series: ", 0
  prompt3  BYTE "The arithmetic mean: ", 0
  n        SDWORD ?
  result   SDWORD 0

.code
main PROC
  call  Crlf                 ; New line
  ; Read the n
  mov   edx, OFFSET prompt1
  call  WriteString
  call  ReadInt
  mov   n, eax               ; n   = eax
  mov   ebx, eax             ; ebx = eax

  ; Calculate the aritmetic series
Loop1:    
  cmp   ebx, 0               ; ebx: n
  je    Divide               ; if ( n == 0 )  goto Divide
  mov   eax, result          ; eax = result
  add   eax, ebx             ; eax = result + n
  mov   result, eax          ; result = eax
  mov   eax, ebx             ; eax = n
  sub   eax, 1               ; n = n - 1
  mov   ebx, eax             ; ebx = n
  jmp   Loop1

Divide:
  ; Print the aritmetic series
  mov   edx, OFFSET prompt2
  call  WriteString
  mov   eax, result
  call  WriteInt
  call  Crlf

  ; Calculate the aritmetic mean
  mov   eax, result          ; eax = sum
  mov   ebx, n               ; ebx = n
  xor   edx, edx             ; clear edx
  div   ebx                  ; eax = sum / n
  mov   result, eax          ; result = eax

  ; Print the aritmetic mean
  mov   edx, OFFSET prompt3
  call  WriteString
  mov   eax, result
  call  WriteInt
  call  Crlf            
  call  Crlf

  exit                       ; Exit to operating system
main ENDP
END main
    An Execution Example 
    Enter the n: 10 
The arithmetic series: +55
The arithmetic mean: +5

    †The white italic text with a navy background color is entered by users.

  5. Build the Project.


  6. Debug the Project.


    7. If the error, Cortex XDR Prevention Alert, happens, it is because the UND prevents the code from being executed on the UND-owned machines. It needs the UIT (University Information Technology) to solve the problem.