Who is aware of what you’ll discover in a second-hand store? [Zeal] discovered some outdated keyboards made to suit early Alcatel telephones from the 12 months 2000 or so. They appeared good however, in fact, had no documentation. He’s made two movies about his journey, and you may see them under.
The connector was a cellphone-style cellphone jack that should carry energy and a few form of serial knowledge. Inside, there wasn’t a lot aside from a significant chip and a membrane keyboard. There have been just a few small help chips and parts, too.
It is a pure job for a logic analyzer. Positive sufficient, urgent a key confirmed some output on the logic analyzer. The gadget solely outputs knowledge, and so, partially 2, [Zeal] provides it to his single-board Z-80 pc.
It makes a cute bundle, however it did take some degree shifting to get the 5V logic to play good with the lower-voltage keyboard. He used a processor to offer protocol translation, though it appears like you can have simply dealt with the entire thing within the host pc software program for those who had needed to take action.
In truth, there isn’t a lot likelihood you will discover this precise keyboard. Nevertheless, the method of opening a wierd gadget and reverse engineering what it’s all about is basic.
Don’t have a logic analyzer? A scope might need been usable for this, however you may also construct one for little or no lately. Utilizing a PS/2 keyboard isn’t actually simpler, by the best way, it’s simply well-documented.
