Funny, I was thinking of Petzold's book when I wrote that. +1 for mentioning it! I still say there are that many layers of abstraction, maybe more. Individual

Funny, I was thinking of Petzold's book when I wrote that. +1 for mentioning it! I still say there are that many layers of abstraction, maybe more. Individual bits, ganged as words, with logic to treat as such, and ability to store and move along a bus. Then you add the ability to act on data: Control logic, arithmetic units, caches, and interpret data as instructions -- microcode running in the CPU, and processor instructions.Now move up to main memory, storage subsystems, networking, graphics (GPUs!!) etc. etc. etc. That gets you through the hardware. Now add software: BIOS, operating system, drivers, user space code, compilers, interpreters, it just goes on and on. And for every one of these giant groups of something, there are just so many logical groupings and abstractions. It's like individual cells in a body, forming organelles, forming organs, forming creatures. So many layers of organization. Amazing beauty. But always at the bottom of the pile, there is a switch.