Tue, 3 Feb 2015, 15:28



Two students have written, asking questions:

> Professor Patt,
>
> I don't see how the .fill directive is at the 9th location. 
>
> <>

The student is talking about the .FILL pseudo op in Figure 7.1 in the 
handout of Chapter 7, which is discussed on page 147 of the handout.
 He is absolutely correct.  The .FILL is in the 11th location.

And, the second student:

> Professor Patt,
> 
> Will we have to worry about detecting an invalid Psuedo-Op? I realize the
> assignment said not to worry about the other valid Pseudo-Ops in the LC-3b
> language like say .PUTS, but for example will something like .GARBAGE be in
> the program we're assembling?
> And if so, do we throw error code 2 for invalid opcode or 4 for other error?
> 
> Thanks,
> <>

Yes, if you see .GARBAGE, you should "throw error code 2" at it, as you say.

Thank you for the questions.  Good luck finishing Lab 1.

Yale Patt