pouët.net

maybe this is a stupid question. but, i'm still curious. i get how they work and can read a truth table. i am wondering though what do they look like and what are they made of? i've seen them as chips. but for a cpu they would have to be alot smaller than the chips i've seen. also, i'm wondering are they just build of wires or what? also, why is it that i see every tutorial demonstrating how they work show moving parts. i thought cpu's contained no moving parts. i don't really need to know this stuff. but i am curious about it and would like to know. thx for any input.

Nothing is logic, nooooothiiiiing.
*evil laugh*

i remember reading about them being made of different types of silicon. but, it's still hard for me to think of how they would make the things. especially as small as i think they would need to be for a cpu. hmm maybe all that mechanical tutorial crap didn't help.

@irokos: err ok ;x muhahaha

Logic gates are made from candy.

i didn't know sugar was conductive. now i know.

That's why god created chemists. So that the electronic engineer doesn't have to deal with that.

I actually had a class about that, but I don't remember anything now. :P
It has to do with electric fields and how some materials react to it... it's hardcore stuff.

hmm well i guess it's good that i don't actually need to know this stuff then. i don't really like electricity anyway. which is odd since my father is an electrician. but, i have been curious as to why people always explain logic gates using something mechanical. rather than showing showing what they are actually made of an animating the current running through it.

Gah, I have an excellent web page bookmarked at work which will answer this question. There's an awesome site about hardware hacking where they literally deconstruct the chip to find exploitable weaknesses.

I'll post on Monday if I remember.

that would be cool. i hope you remember. if not ill try to remember to and bump this thread back to the top. i don't know much about hardware hacking just software. but i am all for learning new things.

they are made up of tiny little tannhauser gates each infinitely manifesting pure logic

logic gates are made from transistors. transistors can be seen as little switches. turn em off and on and the break or open the circuit.

with two switches in series you can make already somekind of AND function. only if both are closed a current will flow. now you need a third transistor to actually measure this. hurrah, you got yourself an AND gate :)

you could actually make an animation of this for all 4 input cases..

(this level of abstraction is good for most digital purposes. but in the analogue world.. there are side-effects everywhere. you can go as deep into the physics as you want. most of that deals with zooming in on the transistors like mad.. but you can also describe gates are ideal switches + some other components which model the side-effects.)

http://en.wikipedia.org/wiki/Tannhauser_Gate
yeah that makes perfect sense

http://www.superphysics.netfirms.com/pp_electronics.html

WRONG FORUM.

Here you go:
http://www.flylogic.net

if you really want to know.

you can make gates in chips, or from oldschool loose components.., transistors themselves are only semiconductor material + maybe some oxidized metals.
with some wiring (tracks in chips, or real wires with loose transistors) you can hook em up. i really recommend the oldschool way if you are visually inclined.

but that's about as visual as you can get. you can't see a electrons or holes travelling. it's an abstract thing. that's why you have to use your brain. you can maybe attach a scope to view what's going on, but that's all.

well you guys are really smart. i understand it alot better than i did before. i'm still not completely sure i know everything that is going on. but, i do know more about what is going on inside. i'll have to check out the old school way as well though. because, making things bigger does seem to help. but, since i didn't actually need to know this information i believe i've got alot of it here. which is why i don't believe i've posted in the wrong forum as kus ma bite says. answers are fast and there are smart people here who know what they are talking about. it looks like the right forum to me. but, i will post a random image if it helps anything jk. well, thanks guys.

The third lead provides a means of affecting the balance enough so that the current can or cannot flow. Once you've designed something that does this repeatably, then you've got a component sufficient to construct the logic gates. It's sort of hack-y really. You could do it in a lot of different ways, with water, mechanically, with weights and scales, whatever.. so long as it's repeatable. It turns out electrons in conductors with the help of semi-conductors that have a manageable balance are an efficient implementation.
disclaimer: I'm not an electrical engineer, chemist, etc.

Hexen: check
http://en.wikipedia.org/wiki/Etching_%28microfabrication
http://csg.csail.mit.edu/6.884/handouts/lectures/L03-CMOS-Gates.pdf (or ppt)

Also, I think it's quite normal if the state of the art doesn't make any sense and appears beyond brilliant. It's the result of a lot of optimizations and tweaks, and pretty much the only way to really understand it is to absorb it by going through some of the older revisions and missteps (which is partly why science journalism is difficult). You've probably made a lot of things yourself that you can't really figure out - you just keep building upon what you've got.

it's like functions in software. but the hardware version? theres alot of information here. i'm still reading this stuff. lol, i feel pretty stupid right now. but, i'm checking it all out. it appears i'm getting alot more information that i thought i was going to get on the subject.

HeXeN: A key here is that there's no magic in it. Some people had realized and theorized that if a component with certain properties were built and then linked together in a certain way, then allowing physics to play out would output a useful computational result. At that point, people just had to create something that fit the specifications. However, the challenge is that they had to use real materials that abide by nature's usual physical laws. So they thought about it and tried some things out -- Some people played with electron flow in conductors, found potential value toward the goal in things that are not great conductors but are rather 'semi'-conductors, found a means to affect the conductivity of these semi-conductors, and wound up with a transistor that fit the objectives of the theory. Then they were linked, and after getting it stable, it computed some results.
This history is entirely falsified, but it's more or less how a lot of things happen.

and of course mechanical computers had been built before as a proof of concept for the theory - but people had yet to build an electronic computer. Probably some of them were excited about the potential and how ridiculously more efficient and quick it might turn out to be, but that's not even so important.

this will demistify it greatly :)

http://youtube.com/watch?v=GcDshWmhF4A

actually i've already seen that wooden adding machine. but, i was wondering more about digital computers rather than something that is mechanical like that. but i did find that video pretty interesting and several other videos on youtube describing logic gates interesting as well. such as this one http://youtube.com/watch?v=tUJ3eqed2nE i'm less interested in function and more interested in how they are built and what they are made of. because i can test the function of them through most programming languages. but if i tried to take a computer chip apart. i wouldn't know where to start and i'd probably end up breaking the chip to. but this was just a question that came up out of curiosity. not need. so, there are no wrong answers and people should probably watch some of those videos on youtube about them if they are curious to.

google can help a lot too ;)