Related discussion <i>Writing a Unix clone in about a month</i>[0] (389 points, 7 days ago, 126 comments)<p>[0]: <a href="https://news.ycombinator.com/item?id=40467297">https://news.ycombinator.com/item?id=40467297</a>
We ran through the Andrew S Tanenbaum OS book and implemented most of MINIX in two semesters in the late 90s at evergreen state, the basketweaving prototype
20ish years ago I met some transfer students to my university and they had mentioned that making your own unix was one of the courses at their previous university.