When I was in engineering school I had a great professor for my controls classes. He was the best. For example, he would take a class poll: "Do we want the test on Friday to get it over with, or Monday so we could study over the weekend?" When the class chose Monday, he offered to come to the school Sunday night after dinner to answer questions and work problems. He was *always* available to help when somebody had a question. About 8 of us would show up on Sunday nights and he'd stay there until we didn't have any more questions. Before the final exam, about 3 or 4 of us were there until about 2:30am and he just kept on going and helping us study and prepare. Great guy.

Anyhow, he was a believer that if you were going to do a certain job you should have the very best tools available for that job. He told a story in class once about buying his first calculator, an old HP dinosaur that cost him over $700 (in 1970 dollars). He would rant and rave about how silly it was to be an engineer with a 4 function solar powered calculator -- something he'd often seen in his classes.

I used his story to rationalize buying a brand new HP48. I *really* wanted this calculator and I couldn't afford it. I bought it anyway. He was right. It was *the* tool for the job.

I was working and taking a pretty full class load and was running out of time to study for a module in his class. It was Nyquist plotting of systems. Rather than cram on the material, I downloaded a Nyquist plotting program for the HP48 and brought it into the exam, thinking that most of the exam would be building the systems model, etc, etc. and that the Nyquist plot would be only part of the test.

When I got there, the whole exam was to create 3 or 4 Nyquist plots from given system equations. I punched them into the HP48, hit "plot" and copied the graphs to the answer book. I had shown absolutely no work. I couldn't have.

5 minutes into the exam I was copying the last graph to the answer book and I noticed the professor was standing behind me and watching what I was doing. I was horrified. I felt "caught" and I was really worried I was going to have to do the plots by hand.

He smiled at me and said, "now *that's* a good calculator," -- and walked away.