A student writes about a personal matter, and then (having got my
attention):


            While I've got your attention I 
        might as well ask you a question about
        the program. The condition codes on the 
        microinstruction sheet are the last
        things I was filling in and I am 
        really confused on how they are determined.
        I don't know if you explained 
        it in class, I may have missed it, but I am
        pretty lost on them. I don't know what is meant 
        by Unconditional, Memory
        Ready, Branch and Addressing Mode and what 
        determines them. I'm guessing
        Memory Ready would have something to do with the R signal, but it can't
        really be used in a state reading from
        memory because the state loops onto
        itself and wouldn't be able to
        set the Cond code. I hope this question isn't
        too general,
        im asking for kind of a large piece of
        the puzzle--if it is too general,
        please point me in the right direction.

Condition codes are set by the logic in the machine every time a GPR is loaded. 
Therefore, all the operates and all the Loads set the condition codes.  And you 
the microcoder will need to make sure the cc are set at the appropriate times.  

The COND field is set by you the microcoder in order to have the next control 
store address correspond to the state you want to visit next.  So, if you select the 
memory ready instance of COND, the next state will be one of two, depending on 
the Ready signal coming out of memory.  If you set the COND field to Branch, then 
the next state will be one of two, depending on what?

Got it?

             Jeez... I keep accidentally writing mini-essays
        every time I e-mail
        you, sorry about that. Hopefully you
        are one of those professors who enjoys
        "interaction" with the students, hah!

	<<name withheld to protect ...>>

I do enjoy interaction with the students.  However, I enjoy sleep also, and with 400 
of you in 306 and 85 in 360N, sometimes I wonder if I should curtail questions.  
BUT, I enjoy you getting it most of all, so if you need help, feel free to keep writing.  
I would prefer you visit one of TAs during his office hour first, however.

Yale Patt