Feel free to talk about what you think of laptops, but at least most of them still carry keyboards with them. [danjovic] There is this old-fashioned Brazilian computer from the 1980s called Gradiente Expert. These are MSX machines with a Z80 chip, running BASIC, DOS and CP/M, and they look like the most advanced dual-deck stereo system. You can still find them easily, but unfortunately, most of them have lost the rad mechanical keyboard with huge arrow keys and proprietary connectors.
If you want to get one of these awesome computing histories now and want to be able to talk to it, [danjovic] Do you know the open source EXPS/2 keyboard adapterIt allows you to use ATMega328P and a customized DIN-13 to DB-13 cable to connect a PS/2 keyboard or USB keyboard to the Expert in standby mode.It turns out that there are Lots of information about the MSX keyboard matrix over there.
How much do you know about the USB keyboard interface?If you want a warehouse of information to be delivered to your brain in the most pleasant way, then go take a look [Ben Eater] Use pen and paper to break it down.