Towards the very end of the 90ies, some introductory CS course had a nice diagram of how general architecture features like memory management, multitasking, net

Towards the very end of the 90ies, some introductory CS course had a nice diagram of how general architecture features like memory management, multitasking, networking, multi-CPU, multi-user OS, virtualization and maybe some others had slowly trickled down from research prototypes to mainframes to personal computers to handheld devices to embedded controllers. Everybody in the lecture hall was mentally continuing the lines and I remember prodding my neighbor, joking about when a successor of the Palm III he was using for taking notes would run a multi-user OS. Android, with its full-blown Linux kernel underneath, came just in time.