# Help Needed

Discussion in 'Homework Help' started by HRG, Jan 27, 2009.

1. ### HRG Thread Starter New Member

Jan 27, 2009
3
0
I have been searching for the use of an OR gate in a computer. I'm looking for a simple use. I have discovered much information that is very difficult to understand. This probably seems like a "stupid" question, but I'm really new to this and any resource would be appreciated.

2. ### KL7AJ AAC Fanatic!

Nov 4, 2008
2,043
292

It might be helpful to think of what an OR gate does OUTSIDE of a computer. Think of a three way light switch in a hallway. If you flip EITHER one OR the other the light goes on. (Actually, this is more accurately an EXCLUSIVE OR gate, because if you flip BOTH of them, the light goes back off.)

The OR gate is one of the fundamental DECISION MAKING circuits, around which you can build countless logic circuits.

Hope this gets you started.

eric

3. ### Wendy Moderator

Mar 24, 2008
20,772
2,540
Add an inverter and make it a NOR, from which you can build every other logic type in existence.

4. ### HRG Thread Starter New Member

Jan 27, 2009
3
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I have discovered the function of an Or gate in daily life. Your examples are what I have used and they make sense. My next question was to answer the function of an OR gate in a computer. With my limited knowledge of this topic, (Real Newbie) I can't relate a hallway light switch to a computer function. BTW, this is a very good forum.
HRG

5. ### veritas Active Member

Feb 7, 2008
167
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still simple logic for decision making. If you press the left shift key OR the right shift key, then the computer recognized that a shift key is being pressed.

At a lower level, a real OR gate will output a logical assertion if either of it's input are logically asserted. The happens in many places in the data or instruction path of the processor and all of the other component in a computer.

6. ### HRG Thread Starter New Member

Jan 27, 2009
3
0

Makes perfect sense to me now. I'm finally starting to understand this. This is a pretty cool forum.