Last month I published an article on the Z80 processor based kit from Wichit Sirichote. In this article I mentioned the type of keyboard used and the fact that I found it unsuitable for this kind of use. Which is why I decided to develop a more suitable keyboard by myself :
Since this publication I have developed the software for the keyboard processor using a real time debugger. The processor used is a low cost generic processor without peripheral. For the moment it is not placed on the printed circuit board because the emulation is made thanks to the 20 pin connector visible on the image below :
As expected, it will suffice to develop a small serial / parallel converter for the processor board to which the keyboard will be connected. This greatly reduces the cost of such an adaptation. I plan to do this for the Omega motherboard I was talking about in the previous article.
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The keyboard provides the code for the key pressed. In order to perform tests, I simply made sure that the generated codes were display characters based on the letter 'A' :
The keyboard does not produce the space code... This test actually comes from the keyboard output. I have to say that the feel provided by the keys is very similar to what one feels with a standard computer keyboard. The goal is reached...
It now remains to convert the Wichit Sirichote kit into an FPGA-based system. I have already implemented this kit on a Digiasic board but I would like to develop a new board with a more recent FPGA and with an I / O port compatible with the MPF1.