I’m surprised there’s no mention of this guy on this whole forum. This guy posts some of the most digestible videos on computer engineering, digital circuitry and networking on Youtube.
He has a couple videos on the workings of keyboards that may be of good use to keyboard builders or the curious.
These videos really get into the nitty gritty of the electronics and protocols
Below is a list of his keyboard-related videos in no particular order
- Very in depth exlpanation of the USB protocol as it relates to keyboards
- Will probably make his other videos more clear when talking about USB.
- He uses a USB decoding oscilliscope to reverse engineer a Das Keyboard 4 Professional to understand how it handles n-key rollover.
- Besides discussing how n-key rollover works, he also provides a great explanation of the switch matrix and the importance of diodes in one.
- He discusses how the PS/2 protocol works and visualizes it well using shift registers.
- He follows this video up by making a hardware interface for a 6502 and then software
- Might provide some insight in to how some keyboards initialize communication and advertise their capabilities to their host.
These videos may be a little dense and aren’t targeting keyboard enthusiasts in particular, but Ben is a good teacher, and this is a good way to de-mystify what many may consider to be a black box in keyboards.