Problem-based tutorial #1
What does this circuit do?


  1. start by examining M=High, Cn=Low; ignore X and Y.
  2. what is pin (14) ?
  3. what is pin (16) ? Why is it called Cn+4? What is Cn?
Student feedback

From: Domenic 

Our group problem solving was not the most successful, we weren’t very organized and
all worked together to try and solve one problem which caused us to waste a lot of
time. We should have broken up to solve a task and see if anyone had any unique ways
to solve the problem, Paul ended up having a good idea to each solve a certain truth
table but we ended up not doing that. I had also suggested we should create a
simulation in Multisim to figure out how it would work but others insisted it would
take too long. This group mentality to only work as a group caused us to take way
longer then it should’ve have and it held us back from completing the problem, because
of that we had only completed half of the circuit. The next time we do group problem
solving we should take everyone’s ideas and try and at least see how their solution
would plan out if it will help solve the big problem. The other thing we should do is
break into groups or do some individual work to help try and understand what is going
on or to break up a big repetitive problem into small tasks that each person
completes. Next time I believe that I should look into the questions we are supposed
to answer more in depth, and then try to think about how I would answer them and
explain to the class.

From: Paul 

This problem based tutorial session proved to be the most interesting yet. As opposed
to previous sessions, I am confidant that each student (Martyn, Christian, Domenic,
and myself) all had the prerequisite skills to be able to solve, understand and apply
Boolean logic to any part of the circuit provided. However, the group failed to pool
each others resources in an effective way, and as a result only an understanding of
the function of the "select inputs" (s0-s3) on the An and Bn inputs was concluded, a
very small portion of the task required of us. As enjoyable as the session was, better
organization and communication amongst group members pertaining to task completion is
required. I suggest for the next session that the group divide ourselves into a
simulation team, and a whiteboard/theory team. The function of the theory team should
be to tackle the questions asked of the group as part of the exercise and then too to
delegate tasks to the simulation team that prove to be either too complex to
understand by hand or too time consuming.  Progress from each team should be reported
at regular intervals (say 15 minutes) to ensure the group stays on task. I look
forward to implementing a strategy similar to this for the next PBT.

From: Martin 

This PBT was an interesting and difficult endeavor. Starting to prepare for the PBT
felt like an insurmountable challenge, but with heavy preparations before the group
work started I felt capable of offering valuable insight to help the group process.
Upon starting with the group I felt the objectives changed quite frequently and we
struggled to identify a single problem to solve. In group work finding a direction and
coordinating efforts is generally a challenging task. The group must be coherent and
confident in their individual abilities to be able to do this effectively. Our group
could have improved on this process by implementing a stronger effort assessing each
members ideas and deciding on a direct flight path for each member. However, I feel
the group persisted and broke valuable ground in a rather unorthodox manner,
re-evaluating the circuit, writing general expressions, and recollecting after each
new insight was achieved, and repeat. Certainly the group did not perform in an
optimal manner, but, given the time constraints, preparation, and scale of the problem
at hand, I feel the group achieved a moderate level of success, and I was proud to
have had the ability to collaborate with my colleagues in this way.

From: Christian

(Late submission)

Yesterday our class tried to decode the use and purpose of a complex circuit.
Although we did not completely solve the method to how said circuit works, we
did identify the circuit and its purpose. The circuit found was a 4-bit ALU
capable of completing mathematical and Boolean operations. This write up is
focused on a self-evaluation and a an evaluation of the groups operation as a

To start I will evaluate the group. About half the group came in highly
prepared, one member spending all the time in between the release of the
circuit diagram figuring out its purpose, with another member was also very
prepared from prior learning and earlier found knowledge. Although it should be
praised in both contexts it did make the group slightly less synchronized as
myself and another member were not on the same page walking in. Another issue
in the group was a disorganized flow of events; although, it was suggested to
make a flow chart, or make a logical matrix of all possible outputs when this
is a logical place to start. Next time I think it would be best to start with
the recommended starting points from the assignment itself and work backwards
with the possible outputs.

In a self-examination I feel torn, prior to the tutorial I had put in about 2
hours of work and had determined the purpose of the circuit but had not fully
grasped the methods to which it worked. When everyone immediately jumped in to
technicalities and was already discussing future parts of the system such as
the counters or the bit shifting design I immediately had nothing to
contribute. When the group was stopped to trying to explain how they came to
any conclusions the explanation was sometimes given to quickly or to general
which only caused more problems as while I was trying to figure out their
methods I was missing more conversation and missing more of their explanations.
Next time I will prepare more and focus more on keeping the group on a single
thread before starting new ones.