Some years ago I posted article describing Universal CAT and programming USB to RS232 TTL interface for ham radio that I made.
Here is small update, adapter for YAESU FT-8900, FT-8800 and alike radios.
FT-8900 and FT-8800 and some other Yaesu radios use two wire interface. One wire is ground and other is both RX and TX. This is also known as CIV-I interface used in Icom radios.
CIV-I interface is quite simple. There is a diode (universal like 1N14148) connecting RX and TX, oriented cathode toward TX, with one 10K pull up resistor to 5V on RX. […]
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