Inside the CS452 Trains Lab
A quiet lab from the outside, pure chaos from within — the trains lab, where trains whir across miniature tracks, and students spend countless hours working away.
CS452: Real-Time Programming is a renowned CS course, notorious for its difficulty but fondly remembered for the deep sense of community it fosters among those who take it.
Professor Martin Karsten, who currently teaches the course, likes to quote a student review from Reddit. “CS452 is not so much a course as a self-discovery journey,” the student wrote. “[It] is really about learning how much you’re willing to sacrifice in pursuit of winning, even facing certain defeat. You will discover just how far you can truly push yourself. And yet, almost everyone comes up short of what they set out to do. I don't think anyone in my class was totally satisfied with their final result.”
Brian Beck (BMath ’87, CS), an alum of the course and now a retired LinkedIn Software Engineer Manager, fondly recalls the experience, saying, “I remember the fun a lot more than I remember the stress of it.”
Other distinguished CS452 alumni include QNX founders Dan Dodge (BSc ’77, MMath ’81) and Gordon Bell (MSc ’80). Building on their CS452 work, they created a real-time operating system that is today used in automobiles, medical devices and trains. QNX is now a division of BlackBerry.
The trains course might seem intimidating at first, but there’s a reason it has endured.
When CS452 was first designed over 40 years ago, model trains presented a real challenge for the computers of the time. Now, computers are significantly faster — but the problem of controlling something in the real world hasn’t changed. “The trains don’t wait for your code,” Professor Karsten says. “If your system lags, the train crashes.”
Read the full article by Haya Kharouba in the fall 2025 issue of Math e-Ties.
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