title: How can I use the ADD instruction with MASM?
body: <p>Here is my code fragment:</p>
  
  <pre><code>    .data
  Num1    equ     40h
  Num2    equ     41h
  Var1    dword   0
  Var2    dword   0
  ;----------------------------------------------------------------------
      align   4
      .code       ;insert executable instructions below
  main    PROC        ;program execution begins here
      mov Var1, Num1
      mov Var2, Num2
  
      add Var1, Var2
  </code></pre>
  
  <p>I am trying to use the ADD instruction but I get the following error:</p>
  
  <pre><code>error A2070: invalid instruction operands
  </code></pre>
  
  <p>This error is related to the ADD line.
  If I omit that line the program runs fine.</p>