Local Tait service centers often provide the software to customers.
That’s when he saw it.
To connect the radio to a PC, you require a specialized interface because the uses inverted logic levels for its serial communication. How to program Tait TM8110 - Ham Radio Programming tait tm8115 programming software
This is usually a COM port mismatch. Go to the "Tools" or "Setup" menu in the software and ensure the COM port matches the one assigned to your cable in Windows Device Manager. Local Tait service centers often provide the software