The textbook in my high school economics class [1] actually devoted a whole chapter to centrally planned economies, covering the methods they used for allocating resources in a fair amount of detail. As an American kid growing up during the cold war, I remember it being one of the more interesting chapters. Looking at the publisher's website, I see that the current edition of the book no longer includes that chapter.

1. https://www.mheducation.com/highered/product/economy-today-s...