ALU information help.

[cameron marical]

So I am just trying to further understand how a computer works down to the core, and am mostly trying to come up with the stuff myself, and I have come to the conclusion that their are two ways a calculator and an alu works.

 

1. the device has the answers to problems already stored in its memory, and when you type a problem, its the same thing as typing in the address in a computer, but this would take a lot of memory, and everything just being bits, its very complex to me. maybe someone can elaborate on this if this is it.

 

2. the device actually does the problem itself, through logic gates or something, I dont know, maybe someone could help me on this if this is true.

 

Are computers just like complex mazes? I just cant wrap my brain around how something can read an instruction and do it. I know that sounds simple, but I try and try to draw ways onto paper myself {because usually, if I need something, my attitude is just invent what you need regardless of what is out there already, and if theres better stuff out there, still draw it all out, then go buy it, now that I would have a complete understanding of what it is and how it works}, but I cant seem to understand it.

 

Maybe if you start with what happens when you press a button, on say a calculator. bits like 01 are represented on two seperate wires right? how else could it be, how could a system register a zero?

 

If someone helps out here, that would be greatly appreciated.

[bascule]

Addition can be performed using adders, which are made out of logic gates:

 

http://en.wikipedia.org/wiki/Adder_%28electronics%29

 

When numbers are represented using Two's Compliment subtraction is the same thing as addition:

 

http://en.wikipedia.org/wiki/Two%27s_complement

 

Multipliers can be constructed out of multiple adders:

 

http://en.wikipedia.org/wiki/Binary_multiplier

 

Multipliers can also be constructed using shifts and adds, which is slower and more complicated. Division can be implemented using shifts and subtraction.

[cameron marical]

Ok, thanks alot. So it is the 2nd.

 

Are integrated circuits just miniaturized versions of bigger machines? I know that I sound like a real simpleton but I am trying to ask very basic questions so I can understand the basics.

 

How does an integrated circuit work? I know that they are made out of semiconductor devices,and I understand what logic gates do, but I dont understand how any of these IC's work, its like black magic to me.

 

From what I have read, they are just transistors, and not only that, but the apollo guidance system was just like 4 transistors {ssi}, how do just 4 transistors guide a spaceshuttle?

 

Do these have addresses for where specific sets are? like heres the adders, and over theres the... they would have to right? it cant just be random wires and gates that bits go through and change.

aghhhh.

I am lost. If anyone can help me out, or give me a good tutorial or link or something, I would be gratefull.

 

Thank you.

Edited August 4, 2009 by cameron marical

[bascule]

Are integrated circuits just miniaturized versions of bigger machines?

 

Yes, integrated circuits could be made out of individual transistors if you so desire, as in physical transistors with three wires sticking out of them, hooked to a logic board or any type of breadboard.

 

How does an integrated circuit work? I know that they are made out of semiconductor devices,and I understand what logic gates do, but I dont understand how any of these IC's work, its like black magic to me.

 

Integrated circuits implement logic gates in a variety of ways.

 

Do these have addresses for where specific sets are? like heres the adders, and over theres the... they would have to right? it cant just be random wires and gates that bits go through and change.

aghhhh.

I am lost. If anyone can help me out, or give me a good tutorial or link or something, I would be gratefull.

 

Thank you.

 

This might be a good starting point:

 

http://en.wikipedia.org/wiki/Von_Neumann_architecture