Now, you can eliminate a lot of diodes by going with discrete logic ICs.
For example, P10 is always ON except when "1" is OFF.
Hence this can be reduced to "1" -> NOT GATE -> P10.
Here is another example, P1 is always ON except for "1" and "2".
In other words, if "1" OR "2" are active, you want P1 to be off.
"1" --)
2-INPUT NOR GATE }O---> P1
"2" --}
Do the same for P4 and P13.
For example, P10 is always ON except when "1" is OFF.
Hence this can be reduced to "1" -> NOT GATE -> P10.
Here is another example, P1 is always ON except for "1" and "2".
In other words, if "1" OR "2" are active, you want P1 to be off.
"1" --)
2-INPUT NOR GATE }O---> P1
"2" --}
Do the same for P4 and P13.



