An interactive explainer
Every program on your machine believes it owns the entire CPU and all of memory. None of them do. The operating system manufactures that illusion by waking for a few microseconds whenever a hardware timer fires, swapping one program for another so fast nobody notices, then going right back to sleep. Watch the trick, break it on purpose, and leave knowing what happens between any two lines of your own code.
Operating systems · Interrupts · Virtual memory
Systems · Intermediate · 11 min · How your operating system fakes an entire computer — an interactive explainer on ViLearn, with a simulation and a knowledge check. All explainers.
Related: Why a log beats a queue when two teams want the same event · Why a road turns red without anyone counting a car · How a cluster decides which server holds your data