How can I detect if only one out of 8 lines of redstone is on and block the others from passing trough?

I have a (very) big redstone contraption used to store numbers for ALU's or minecraft computers. As of with most inventions, They get upgraded to preform better/get smaller from time to time, so to make it better, In this case easier to use I am adding some aditional features like Reversing and bit-shifting. For better understanding of the problem I probebly need to explain exactly how this devise works:

The device is made out of 8 cells each made out of 8 RS Nor-based latches. These cells can each be selected here on the orange lines on the SIA(Short for Selector Input Area). As you can see thee is not much space there due to the black lines coming across

So basically what I want to do is make it so only one line can be activated at the time (In this case all lines are activated) The lines are spaced out like this one line, one air block, one line, one air block, and so on. The length of the measuring device should be around 4-5 blocks wide (or 4 blocks across the length of the lines so it does not touch the black lines) but it can be as tall and long as you want.

I tried several designs for fixing this problem but all of them failed by causing a clock rather than turning of access for the lines to pass trough a signal. Does anybody know how to do it?

Here are some other pictures for those interested: As you can see here the selection part I was talking about is in the down left corner of the picture. (The orange lines if you didn't understand already).

Here is the other side of the device which can also be used if you want for the device.