So how does a PS/2 keyboard interface work?
Why Hacker News recommends it
HN commenters point to it as the clearest explanation of the PS/2 protocol, usually when keyboard interfaces come up.
What it is
Ben Eater explains how the PS/2 keyboard interface works, covering its clocked serial protocol and scancodes. He builds up the hardware-level understanding needed to read keypresses.
Recommended by 1 HN commenters across 1 different months, 2021 to 2021.
What Hacker News said
Recommends zackbloom · 2021-04 · on “The last generation of typewriter repairmen (2010)”
There's a good video on how PS/2 works here: [this video] It's pretty straight-forward. There are also pre-made kits for digitizing typewriters if that interests you.
Cites thristian · 2021-07 · on “How does USB device discovery work? [video]”
Piggy-backing this comment to add some context for the OP video: This "USB device discovery" video is actually the latest in a series of videos where Ben Eater is building a simple 8-bit computer on breadboards. He hooked up a PS/2 keyboard as an input device, and then got sucked into a tangent of investigating and explaining keyboard protocols. - He investigates the PS/2 keyboard protocol: [this video] - Somebody on Patreon asked about USB keyboards having higher latency than PS/2, so he made a video about the basic USB protocol: [LINK] - He made the OP video about USB keyboards being limited to holding six keys at once.
Cites bear8642 · 2021-09 · on “It's Time for Operating Systems to Rediscover Hardware”
think might be at end of this one < [this video] > though there's a few he's done recently on USB spec
Cites RJIb8RBYxzAMX9u · 2021-10 · on “IBM PS/2 Keyboard Modification”
I'd imagine it would be very difficult, and would require a relatively powerful MCU. Ben Eater's made a few videos discussing how PS/2[0] and USB keyboards[1] work. USB's a vastly more complicated protocol compared to PS/2. [0] [this video] [1] [LINK]