As a young, new professor at a college, I was to be assigned a mentor to help me learn the ropes of teaching, along with all the other assignments I would have. When I arrived at work that first week, I was happy to learn that my mentor would be Professor Hoagland. I had him as a teacher when I was a student and knew him as one of the most brilliant people I had ever met.
One of the classes I took from him was called “Scientific Programming in Fortran,” and we used punch cards. The class required some prior programming experience and calculus as prerequisites. It was one of the most intense courses I have ever taken. When I got my first test back, I was shocked to have received 54% on it. I was even more shocked later to learn that it was the highest score in the class.
Professor Hoagland didn’t expect you to actually pass the class that easily. Instead, he gave bonus programming assignments a person could do to make up the difference, and everyone ended up needing to do them.
These programs required extensive programming skills and a strong background in math. They were also so intensive that the college’s computers wouldn’t run them. They were, therefore, sent by modem to a CDC computer owned by a company in California. The college paid for the time students used on it.
The CDC was one of the biggest supercomputers of the time. Thus, the computer time was costly. Therefore, we had one strict requirement in the class. That requirement was a segment of code that had to be at the front of each person’s deck of punch cards. That code told the computer to exit the program if it ran for more than seven seconds. This was to ensure we didn’t get caught in an infinite loop and run up a huge bill.
The CDC computer had a built-in automatic kick out after fifteen minutes, but fifteen minutes of computer time on it cost the college more than fifty thousand dollars. Based on inflation, that would be more than $178,000 today.
If a person forgot that code and the computer ran for the full fifteen minutes, that person would be kicked out of school and billed for the computer time. That was in the syllabus, and we discussed it at length on the first day of class.
Well, as can be expected, about halfway through the semester, somebody forgot the code, their program got caught in an infinite loop, and it ran for the default fifteen minutes. Consequently, the college received a bill for more than $50,000.
Professor Hoagland was as compassionate as he was brilliant, and he didn’t want to have to implement the punishment against the student who had made a simple, honest mistake. That kind of punishment, especially the bill, could create havoc for a person for the rest of their life.
He called the company that owned the CDC computer and was eventually transferred to the director of the computer center. Professor Hoagland begged the director of the computer center to forgive that debt. But the director wouldn’t budge on it. In addition, he was extremely rude.
Finally, exasperated, Professor Hoagland said, “Your stupid computer isn’t without its own flaws.”
The director laughed. “And just what flaws does it have?”
“A person could run a program on it and run the clock backward,” Professor Hoagland said. “Then what would you do about the calculation of the bill?”
“That’s absolutely impossible,” the director said.
“I’m sure I could do it,” Professor Hoagland said.
The director laughed. “I dare you to try.”
So, with that challenge in mind, Professor Hoagland set out to do exactly that: have the machine run the clock backward the next time we submitted programs to run on it.
(To be continued)
