Difference between revisions of "Talk:Z80 STI RS232 interface"
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− | The symbol in the Schematic for the 74LS20 is incorrect (Should be a 4 input NAND gate). 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 | + | The symbol in the Schematic for the 74LS20 is incorrect (Should be a 4 input NAND gate). |
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+ | 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. |
Revision as of 12:00, 10 May 2010
The symbol in the Schematic for the 74LS20 is incorrect (Should be a 4 input NAND gate).
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.