What I am trying to do is have one 7 seg display have 2 separate inputs controlled by a switch. So it receives a signal from one IC to display the numbers, flick a switch, and the first IC turns off and a second IC connected to the 7seg turns on controlling what is displayed. Keeping what was displayed when switching is not necessary. I have attached a diagram to try to better explain what I am talking about.
rb0 is to be held high or open when an o/p is desired so you will have to connect a gnd inorder to disable them.As far as rb1 is concerned it concerns the decimal i/p so i dont think you need to connect it to a switch
There will never be an occasion where both inputs will be sending a signal (Turned on) at the same time so your options seems a little overkill to me. Would I just be able to put a diode either side of the connections to the 7seg to stop the signal passing through to the other output?
I assumed you were asking for suggestions of how to achieve what you described. Two LS257s feeding two LS48s does this and is still only 4 chips. If this isn't what you were after then what is your question?
If only 1 set of signals will be present at any one time then why do you need the switch, why not just OR the incoming signals together?
Sorry I got a little confused. I was looking at the output to the 7 seg and ways to switch the a - g outputs. That's why an outsider point of view is so good. I got so focused on that, I thought you were suggesting 2 chips per 7 seg. Not one chip to switch the bcd input & making the need for only 1 74ls48. Yes an or gate will work fine. Do you think a cd4071 be suitable?