Yeah, haha I admit I never bothered to check the depths of how low it would go for anything lower than a B+. For CS wannabes, getting a grade below a B in any of the 3 classes is asking for a lot of trouble as far as qualifying goes.
Do note that for 61B, there’s a big difference in how things are emphasized in terms of grading along with style between Professors Hilfinger and Hug (the 2 that teach the course). Hug - great lecturer, tougher grader, emphasis more on exams, projects are easier. Hilfinger - much much greater emphasis on coding, as his class is mostly graded on projects. Workload is more with Hilfinger since you spend way more time on the projects though, unless you are already a great programmer.