Student "edition" found at {csi dot journalspace dot com}.

Maybe I shouldn't have started this blog now, not with everything that's been going on.

In the last meeting of my Computer Systems Organization class for the seventh week of the third term, my lecture was about subtracting computational circuits, magnitude comparators, encoders and decoders.

I was already in a bad mood when I got into the room, because not only were half of the students missing, but the half that was there was doing an assignment for another class.

I asked them to move to the front of the room so that I did not have to shout, besides needing to gain their attention from what they were doing.

I started out talking about the two bit subtracting circuit slowly and in detail, but other factors began to sour the disposition I was trying to keep cheerful. One student snapped at me when I tried to make small talk politely while some of her classmates were on the board solving something. Another supposedly honor roll student started parroting my words while I lectured.

I not only slipped into what I was discussing that they would have an exam on the next meeting, but I also rushed my lecture so that I was able to cover three bit subtracting circuits and two and four bit magnitude comparators as well. This I accomplished by passing of a lot of the more advanced topics as reading assignments.

I also tried to explain to them the logic behind the circuit of the magnitude comparator that did not use truth tables and K-maps (the same way people can say which of two multi-digit numbers is higher, by looking at the higher placed numbers first), but somehow the combination of my mood and theirs did not make them receptive, so we went back to the old methods just to finish that circuit. The only intuitive part we got to was when to say that two two-bit numbers are equal, by using two exclusive or gates, put through another or gate and inverted.

From there I whisked through the description of encoders and decoders, for which one having N bit inputs would mean getting two raised to the N outputs, and vise versa for the other.

I only discussed when N is equal to two and three for them, and left the rest as a reading assignment.

Session 1013 also spoiled my initial positive outlook for the rest of the period. Class dismissed.