The book this is from, David Ahl’s More BASIC Computer Games, was hugely influential on me when I was 12. After my parents sent me to bed I’d read it under the covers trying to imagine how the computer would behave at every step. Great times!
In addition to Dartmouth (which made BASIC available to other schools, including offering remote access), David Ahl evangelized BASIC while working for DEC, and ended up catalyzing the microcomputer revolution (which BASIC was a big part of):