Answers.Body: <p>Credit where it’s due, Keshav Saharia’s gates were an attempt to simplify those found here:</p>
  
  <p><a href="http://www.randomwraith.com/logic.html">http://www.randomwraith.com/logic.html</a></p>
  
  <p>If you look carefully Keshav's gates you'll see that they suffer from a fundamental flaw in that they can't be reset, the input rods are completely decoupled so pulling them out does nothing.</p>
  
  <p>RW </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-29T20:13:11.457Z
Answers.Text: Glad your site is back up now - at the time I'd linked to Keshav's post, the link to your original blog was dead :( I'm also not sure what you mean with the decoupled comment - it looks to me that you can indeed move the input rods back out and effect the output, due to the hinging effect on the levers.
Answers.UserDisplayName: Zhaph - Ben Duguid
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-29T05:29:29.200Z
Answers.LastActivityDate: 2012-05-29T05:29:29.200Z
Answers.UserDisplayName: Randomwraith
Answers.Body: <p>There's this project, and with a mechanism like that you have a pretty high limit on the complexity of what you can do:</p>
  
  <p><a href="http://www.youtube.com/watch?v=SYi9sJkS19Q" rel="noreferrer">http://www.youtube.com/watch?v=SYi9sJkS19Q</a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-01-24T23:14:24.377Z
Answers.LastActivityDate: 2012-01-24T23:14:24.377Z
Answers.UserDisplayName: Mark Langen
Answers.Body: <p>Various people have done this - however most of the links seem to point to a [then defunct] blog by <a href="https://web.archive.org/web/20140802185936/http://goldfish.ikaruga.co.uk/logic.html" rel="noreferrer">Martin Howard (Randomwraith)</a> from 2004.</p>
  
  <p>A more recent, and available, post on this, using newer pieces can be seen here:</p>
  
  <blockquote>
    <p><a href="http://web.archive.org/web/20140206173429/http://keshavsaharia.com/2011/05/29/lego-logic" rel="noreferrer">LEGO Logic</a> by <a href="https://bricks.stackexchange.com/users/567/keshav-saharia">Keshav Saharia</a></p>
  </blockquote>
  
  <p>Based on a lack of gears and rack and pinion elements, Keshav decided to rebuild the logic gates using an approach based around levers. Extra care was taken to ensure that the movements were uniform so that the outputs moved the same distance as the inputs.</p>
  
  <p>Starting with the simplest gate, a NOT Gate was built:</p>
  
  <p><img src="https://i.sstatic.net/ZjZt1.jpg" alt="2 NOT Gates"></p>
  
  <p>Then going back to first principles, a NOR Gate:</p>
  
  <p><img src="https://i.sstatic.net/b1Oc4.jpg" alt="A NOR Gate"></p>
  
  <p>Combining a NOR with two NOTs gives an AND Gate:</p>
  
  <p><img src="https://i.sstatic.net/Ulyl3.jpg" alt="A NOR and 2 NOTs make an AND"></p>
  
  <p>Finally Keshav built the XOR Gate out of 3 NORs and 2 NOTs (or 2 NORs and an AND):</p>
  
  <p><img src="https://i.sstatic.net/B0zIQ.jpg" alt="The whole XOR Gate"></p>
  
  <p><img src="https://i.sstatic.net/sN6WD.jpg" alt="Detail of XOR Schematic"></p>
  
  <p>All images used <a href="https://bricks.stackexchange.com/questions/86/is-it-possible-to-build-simple-logic-gates-with-lego-mechanics/112#comment1842_112">with permission</a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-10-28T19:33:08.563Z
Answers.Text: I think those gates work only in small scale, because of the friction.
Answers.UserDisplayName: Sibbo
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-03-11T01:35:11.177Z
Answers.Text: Thanks for the link to my blog! By the way, you have my permission to use my images. I'm not really into the whole copyright thing so feel free to use them. Credit would be nice :)
Answers.UserDisplayName: Keshav Saharia
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-06-21T14:45:09.357Z
Answers.Text: I'll offer a bounty of 100 to anyone who creates an SR latch and explains why Q or ~Q is set when the inputs are 0 and 0.
Answers.UserDisplayName: tuskiomi
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-10-25T21:43:15.203Z
Answers.Text: Thats a great link.. maybe someone could build a computer ;)
Answers.UserDisplayName: Sibbo
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2011-10-25T21:39:38.787Z
Answers.LastActivityDate: 2016-07-17T22:13:42.127Z
Answers.LastEditDate: 2017-04-13T12:47:56.390Z
Answers.UserDisplayName: Zhaph - Ben Duguid
Body: <p>I built a simple bitshifter in Minecraft yesterday. I wondered if something like this could be built with LEGO?</p>
  
  <p>Maybe there is a possibility to build gates with rubber bands and those movable mechanic stuff. Did anyone of you do something like this?</p>
  
Tags: <technic><building><electronics><mechanical>
Title: Is it possible to build simple logic gates with LEGO mechanics?
UserDisplayName: Sibbo
ThreadText: # Is it possible to build simple logic gates with LEGO mechanics?
  
  (Asked by: username_0 on 2011-10-25)
  
  I built a simple bitshifter in Minecraft yesterday. I wondered if something like this could be built with LEGO?
  
  Maybe there is a possibility to build gates with rubber bands and those movable mechanic stuff. Did anyone of you do something like this?
  
  **Tags:** technic, building, electronics, mechanical
  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_2 on 2011-10-25. Score: 59 | Accepted answer
  
  Various people have done this - however most of the links seem to point to a [then defunct] blog by [Martin Howard (username_1)](https://web.archive.org/web/20140802185936/http://goldfish.ikaruga.co.uk/logic.html) from 2004.
  
  A more recent, and available, post on this, using newer pieces can be seen here:
  
  > [LEGO Logic](http://web.archive.org/web/20140206173429/http://username_4.com/2011/05/29/lego-logic) by [username_4 username_4](https://bricks.stackexchange.com/users/567/username_4-username_4)
  
  Based on a lack of gears and rack and pinion elements, username_4 decided to rebuild the logic gates using an approach based around levers. Extra care was taken to ensure that the movements were uniform so that the outputs moved the same distance as the inputs.
  
  Starting with the simplest gate, a NOT Gate was built:
  
  ![2 NOT Gates](https://i.sstatic.net/ZjZt1.jpg)
  
  Then going back to first principles, a NOR Gate:
  
  ![A NOR Gate](https://i.sstatic.net/b1Oc4.jpg)
  
  Combining a NOR with two NOTs gives an AND Gate:
  
  ![A NOR and 2 NOTs make an AND](https://i.sstatic.net/Ulyl3.jpg)
  
  Finally username_4 built the XOR Gate out of 3 NORs and 2 NOTs (or 2 NORs and an AND):
  
  ![The whole XOR Gate](https://i.sstatic.net/B0zIQ.jpg)
  
  ![Detail of XOR Schematic](https://i.sstatic.net/sN6WD.jpg)
  
  All images used [with permission](https://bricks.stackexchange.com/questions/86/is-it-possible-to-build-simple-logic-gates-with-lego-mechanics/112#comment1842_112)
  
  > **Comments:**
  > **username_0**: Thats a great link.. maybe someone could build a computer ;)  
  > **username_0**: I think those gates work only in small scale, because of the friction.  
  > **username_4**: Thanks for the link to my blog! By the way, you have my permission to use my images. I'm not really into the whole copyright thing so feel free to use them. Credit would be nice :)  
  > **username_5**: I'll offer a bounty of 100 to anyone who creates an SR latch and explains why Q or ~Q is set when the inputs are 0 and 0.  
  
  ---
  
  ### Answer by username_1 on 2012-05-29. Score: 6
  
  Credit where it’s due, username_4 username_4’s gates were an attempt to simplify those found here:
  
  <http://www.username_1.com/logic.html>
  
  If you look carefully username_4's gates you'll see that they suffer from a fundamental flaw in that they can't be reset, the input rods are completely decoupled so pulling them out does nothing.
  
  RW
  
  > **Comments:**
  > **username_2**: Glad your site is back up now - at the time I'd linked to username_4's post, the link to your original blog was dead :( I'm also not sure what you mean with the decoupled comment - it looks to me that you can indeed move the input rods back out and effect the output, due to the hinging effect on the levers.  
  
  ---
  
  ### Answer by username_3 on 2012-01-24. Score: 6
  
  There's this project, and with a mechanism like that you have a pretty high limit on the complexity of what you can do:
  
  <http://www.youtube.com/watch?v=SYi9sJkS19Q>
  
  
  ---
  
  