The k and m firmware won't run on an unmodified TC-1 because of the additional MCU U4. But it's possible to replace U4 with a small circuit which I've posted on this page. Also I've run into problems with the TC-1's power supply, it's not stable. The "Clones" file is in the m-firmware's tgz archive and lists settings for a few clones and some hints. And here's the wiring of the LCD for your diagram:
PB7 (SCK) - LCD SCK
PB6 (MISO) - LCD SDA
PB5 (MOSI) - LCD A0
PB4 - LCD /RESET
If the designer of the clone would have payed more attention to the pin assignment the TC-1 would be able to use the hardware SPI for driving the LCD.
I agree it is annoying that they don't publish their changes to the code or schematic. Given that there are a lot of these units out there, which will most likely end up faulty and people want to get them going or upgrade them with newer features functions: Isn't it possible to modify the "m" version code to support the configuration utilising U4. I am happy to try and give the changes a go. I have a working TC1 with original 324 chip I can use to check things (take measurements) and also as a reference. I have another one I am trying to modify which now has a blank 644 in place.
For reference the 2 PCB's appear to be almost the same. Only differences I have spotted are (as per my schematic in previous post) C11 now has a second Cap C12 in parallel and any higher numbered Caps have been renumbered by +1 (C12-C23 become C13-C24). EN pad had been moved from the edge to near the middle. D2 is physically smaller. All of the other traces and vias and components on the PCB appear to be placed and route exactly the same. I will draw an updated diagram and post if it anyone wants it. I can also take a picture of the 2 different but similar PCB's and post those if people are interested.
I do want to get my second unit with the 644 working with more of the new code features eventually, also very keen to try and contribute in any way I can to help others. I have adequate test gear for the task (lab bench supplies, 4ch digital and analogue scopes, 5 1/2 digit mm, basic signal generator, simple logic analyzers, tools for surface and PTH rework, AVR JTAGICE3...).
I am new to the source repository and find this thread very useful but still not sure which repository version to download as a starting point for converting a TC1 with ATMEGA 324. I downloaded ComponentTest 1.33m and it does not have an archive folder, so I must have the wrong file.