thank you, tllim, your generosity is inexhaustible. but I do own such a console, I bought it from the Pine64 store, so no need to worry. My problem is not with the USB-UART adapter, it is with utilities - minicom, cu, screen. they don't work with the set up I need to use. I tried to explain this in the OP, but apparently failed on that.
ANT - my hobby OS for x86 and ARM.