Not just how it physically looks but, y'know, the vibes.
Athlon XP for me, easy.
the atom processors produced the BIGGEST variety of devices in the history of the personal computer platform. the like 2007-2011 era was populated with gobs of second- and third-gen netbooks, but also just bizarre little Gadgets that happened to run windows and linux (and in many cases, macos via hackintosh.) You could get palmtops with tiny thumb keyboards and smart barcode scanners and weird cop car tablets with strange docks. all kinds of wacky shit that ONLY existed because the atom made x86 easy to put in a package of any imaginable size and shape, and delivered almost as much battery life as arm platforms. and the performance was like... bad, yes, but like celeron bad. non-ideal, but completely reasonable if you weren't being deliberately obtuse about your expectations. the atom was the crowning achievement of mids. we stan a regular guy.
It's the microprocessor that I learned as an undergrad, and it's simple enough to kind of hold the whole thing in your mind. It only has two 8-bit general-purpose registers (which can sometimes be used as one 16-bit register), and two 16-bit index registers. (Our professor told us that not having registers would teach us how to use the stack when programming in assembly, and he was right!) It even comes with a built-in DAC!
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