Your interpretation of the schematic in Note 2 is also incorrect. The combination of the 74LS138 followed by the 74LS20 means that the STI is mapped to ANY/ALL of the four lower addresses decoded from the 3 Address pins at the input. This is of course required for the circuit to function properly and definitely NOT nonsense to avoid legal issues as you suggest.
:Bryce, my interpretation in Note 2 is EXACTLY the same as what you are saying. It maps to ALL four addresses.
:Thus, the decoding of the "lower" two addressbits (A2,A3) is total nonsense, really. --[[User:Nocash|Nocash]] 19:15, 10 May 2010 (UTC)