[SiriusHardware]

Each binary value which UC7 outputs on pins 2, 3, 4, 5, should select a particular output of UC9, but we knew from the analysis of the keys pressed / characters returned that either:

-Bit 0 of the 4-bit code was not being correctly output by UC7

or

-Bit 0 of the 4-bit code was being correctly output by UC7 but was being ignored / misinterpreted by UC9.

The latest results show that UC7 is generating the expected 4-bit codes and sending them to UC9, therefore we conclude that UC9 is not responding correctly to those 4-bit codes because it is faulty.