title: Why operand must have size in one line but not the other in x86 assembly
body: <p>Looking at the picture, on line 34 I had to write the <code>word ptr</code> for this to work, while on line 44 I didn't.<br>
  Why is that? <a href="https://i.stack.imgur.com/JxKR7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JxKR7.jpg" alt="image"></a></p>
  
  <p>Can't the compiler know that 0020h is a word just like 0FF20h is a word?<br>
  Adding 0 to 0020h making it 00020h or anything like that doesn't work either.</p>
  
  <p>I am using MASM on 80x86. emu8086, also tried on dosbox v0.74</p>