Where the Universal Micro Keyboard connects?

[davi...@gmail.com]

Hi everybody,

I have a spare Amstrad CPC keyboard and an ATMEGA328 lying around, so I was thinking to do something similar to the Universal Micro Keyboard.

But I don't fully understand where would it be connected. I'm currently using the RC2014 with and FTDI cable on SIO/2 Port A. Where the UMK connects then? To the Port B and work seamlessly with the FTDI? Or only works without the serial being used, hence I would need something to get video out?

Thanks a lot in advance.

[Phil G]

The universal micro keyboard is a transmit-only device, it only sends TO the computer.  You also need a means of displaying data coming FROM the computer - the Geoff Graham terminal chip is ideal.

The FTDI simultaneously works on transmit and receiver to a one common device - ie teraterm on a PC.  The UMK/GG solution splits transmit & receive into two separate devices.

The GG chip is really versatile and really simple - justa pic,a  crystal and not much else.  Ignore the full diagram, use the simplified diagram towards the bottom of Geoff's page:  https://geoffg.net/terminal.html

[davi...@gmail.com]

Hi Phil,

thanks a lot for the information, but I don't understand why I need yet another circuit. The SIO/2 manual specifies that it has two independent full duplex channels. So I thought it would be possible to have UMK in Channel A and FTDI from teraterm in Channel B. Am I incorrect? Or is just a software limitation?

[Alan Cox]

On Wed, 8 Jun 2022 at 08:44, davi...@gmail.com <davi...@gmail.com> wrote:

Hi Phil,

thanks a lot for the information, but I don't understand why I need yet another circuit. The SIO/2 manual specifies that it has two independent full duplex channels. So I thought it would be possible to have UMK in Channel A and FTDI from teraterm in Channel B. Am I incorrect? Or is just a software limitation?

If you only plan to type on one of them you can just split the serial cable - rx to one and tx to the other. In software it depends on your version of CP/M and the BIOS what is supported in terms of splitting input and output.

Alan

 

[davi...@gmail.com]

Thanks a lot Alan. I didn't think about splitting the cable. It makes sense.

[Phil G]

I use the RC2014 Universal Micro Keyboard in various projects, its really convenient. Spencer provides the files for a laser cut case but I dont have a laser so I've just done a printed case for it. Theres a zip on the 'Retro' page of https//philg.uk with the stl files and a code update giving caps lock and switchable baudrates. On FB too. Cheers - Phil_G