Support for the original keyboard

A project log for TMS9900 compatible CPU core in VHDL

Retro challenge 2017/04 project to create a TMS9900 compatible CPU core. Again in a month... Failure could be an option...

erik-piehlErik Piehl 01/02/2018 at 20:083 Comments

A quick addition of the day - this one was really easy to do as interfacing to a normal TI keyboard from the FPGA is way easier than communicating with the PC's keyboard through USB and the server process.

The implementation quite literally only involved in bringing out the keyboard row / column wires from my TMS9901 interface chip implementation inside the FPGA. There are no external active or passive components other than the keyboard switches, thanks to the internal pull-ups of the FPGA.


Erik Piehl wrote 09/18/2018 at 10:12 point

Hi Dave,  I have been moving house this summer, sorry for the silence... there's been a lot of activity outside of my VHDL hobby domain but I will be getting back to the project. I am aware of at least one divider bug that I want to fix, need to write more test cases...

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Dave's Dev Lab wrote 09/17/2018 at 19:36 point

any updates?

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Dave's Dev Lab wrote 01/02/2018 at 21:31 point


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