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      Oops!  Too right, Weston.<br>
      <br>
      Like they say, as simple as possible but no simpler....<br>
      <br>
      On 1/16/2014 10:59 AM, Weston Turner wrote:<br>
    </div>
    <blockquote
      cite="mid:C7D9892C-B798-4F98-B493-504ED18FEB09@gmail.com"
      type="cite">
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      <div>Bob,</div>
      <div><br>
      </div>
      <div>Just having fun mainly. But it is part of an application...</div>
      <div><br>
      </div>
      <div>Darrell, I don't think the second drawing will produce the
        logic table specified because both XOR gates will output a high
        when A != B. The first drawing satisfies the table though.<br>
        <br>
        Regards,
        <div>Weston</div>
      </div>
      <div><br>
        On Jan 16, 2014, at 10:40 AM, Bob Miller <<a
          moz-do-not-send="true" href="mailto:kbob@jogger-egg.com">kbob@jogger-egg.com</a>>
        wrote:<br>
        <br>
      </div>
      <blockquote type="cite">
        <div>
          <div dir="ltr">So is this a homework problem, a circuit you're
            building, or just keeping the minds limber?</div>
          <div class="gmail_extra"><br>
            <br>
            <div class="gmail_quote">On Thu, Jan 16, 2014 at 10:26 AM,
              Darrell Perko <span dir="ltr"><<a
                  moz-do-not-send="true" href="mailto:dperko@efn.org"
                  target="_blank">dperko@efn.org</a>></span> wrote:<br>
              <blockquote class="gmail_quote" style="margin:0 0 0
                .8ex;border-left:1px #ccc solid;padding-left:1ex">
                <div bgcolor="#FFFFFF" text="#000000">
                  <div><br>
                    Realized there was a neater wiring arrangement. 
                    With no feedback it should clock faster, too, all
                    else being equal.<br>
                    <br>
                    <br>
                    <gahhahcb.jpg>
                    <div>
                      <div class="h5"><br>
                        On 1/16/2014 9:46 AM, Mr. Clif wrote:<br>
                      </div>
                    </div>
                  </div>
                  <div>
                    <div class="h5">
                      <blockquote type="cite"> Wow Darrell,<br>
                        <br>
                        that is elegant, no inverters.. :-)<br>
                        <br>
                        <div>On 01/16/2014 09:39 AM, Darrell Perko
                          wrote:<br>
                        </div>
                        <blockquote type="cite">
                          <div><br>
                            Yeah, I suppose it is normal.  That's what
                            the clock is for after all.<br>
                            <br>
                            Attached is my (messy) schematic.  AND on
                            the left, two XOR on right.<br>
                            <br>
                            <mime-attachment.jpg><br>
                            <br>
                            On 1/16/2014 8:58 AM, Mr. Clif wrote:<br>
                          </div>
                          <blockquote type="cite"> Way to go Darrell!<br>
                            <br>
                            That sounds perfectly normal except that if
                            I understand you correctly you would say
                            that the output of the AND gate propagates
                            into the inputs of the XORs.<br>
                            <br>
                            After I went to bed last night I realized
                            that with the MC10H104 I can also do it with
                            three of the four gates in just that one
                            package. So not only can I do it in three
                            gates I can also do it without buying
                            several different gate packages.<br>
                            <br>
                            Ok Weston you've got two guys that claim to
                            have solved it in three gates! :-p what now?<br>
                            <br>
                                Clif<br>
                            <br>
                            <div>On 01/16/2014 03:21 AM, Darrell Perko
                              wrote:<br>
                            </div>
                            <blockquote type="cite">
                              <div><br>
                                I think I have a solution using two XOR
                                and one AND, though the AND is both an
                                output and it feeds back into the input
                                of the XORs.  That seems like it could
                                cause brief illegal outputs states.<br>
                                <br>
                                On 1/15/2014 11:49 PM, Mr. Clif wrote:<br>
                              </div>
                              <blockquote type="cite"> Ok here is a Quad
                                and gate part that you can do it with
                                just one package:<br>
                                <br>
                                MC10H104<br>
                                <br>
                                there may be others.<br>
                                <br>
                                    Clif<br>
                                <br>
                                <div>On 01/15/2014 10:40 PM, Mr. Clif
                                  wrote:<br>
                                </div>
                                <blockquote type="cite"> Ok ;-)<br>
                                  <br>
                                  So when you say that "<span
                                    style="font-family:courier
                                    new,monospace"><font
                                      face="arial,helvetica,sans-serif"><span
                                        style="font-family:courier
                                        new,monospace"><font
                                          face="arial,helvetica,sans-serif">inverting

                                          operations count as NOT gates</font></span></font></span>"
                                  do you mean that they aren't counted
                                  as gates or that they are "Not
                                  operations"  implemented as gates,
                                  which of course they are?<br>
                                  <br>
                                  One issue with doing this your way in
                                  hardware, is that you need three
                                  different types of gates unless you
                                  are doing it in an FPGA or the like.<br>
                                  <br>
                                  Here it is in a shorter logical
                                  expression:<br>
                                  <span style="font-family:courier
                                    new,monospace">C = <span
                                      style="background-color:rgb(255,242,204)">A
                                      & B</span>; D = <span
                                      style="background-color:rgb(217,234,211)">!C


                                      & A</span>; E = <span
                                      style="background-color:rgb(207,226,243)">!C
                                      & B</span></span><br>
                                  <br>
                                  I have another way that uses four of
                                  the same kind of gate though they may
                                  be some what uncommon. ;-)<br>
                                  <br>
                                      Ciao,<br>
                                      Clif<br>
                                  <br>
                                  <div>On 01/15/2014 10:04 PM, Weston
                                    Turner wrote:<br>
                                  </div>
                                  <blockquote type="cite">
                                    <div dir="ltr">
                                      <div><span
                                          style="font-family:courier
                                          new,monospace"><font
                                            face="arial,helvetica,sans-serif"><span
                                              style="font-family:courier
                                              new,monospace"><font
                                                face="arial,helvetica,sans-serif">From
                                                a more rigorous or
                                                theoretical standpoint,
                                                the inverting operations
                                                count as NOT gates</font></span>.
                                            But I guess I didn't say
                                            that inverting equals a NOT.
                                            In any case, my four gate
                                            solution doesn't use them.
                                            I'll represent it here in
                                            Python using four binary
                                            bitwise operators, one AND,
                                            one OR, and two XORs. <br>
                                            <br>
                                            A and B are anded to make C<br>
                                            A and B are ored  together
                                            into the temp variable t<br>
                                            t is xored with B to make D<br>
                                            t is xored with A to make E<br>
                                            <br>
                                          </font></span></div>
                                      <div><span
                                          style="font-family:courier
                                          new,monospace"><font
                                            face="arial,helvetica,sans-serif">The

                                            operations are color coded
                                            below. Can this be done with
                                            fewer operations?<br>
                                          </font></span></div>
                                      <div><span
                                          style="font-family:courier
                                          new,monospace"><br>
                                          Python 2.7.3 (default, Nov 11
                                          2012, 18:06:39) <br>
                                          >>> <b>A, B = 0, 0</b><br>
                                          >>> t = <span
                                            style="background-color:rgb(244,204,204)">A
                                            | B</span>; C = <span
                                            style="background-color:rgb(255,242,204)">A
                                            & B</span>; D = <span
                                            style="background-color:rgb(217,234,211)">B
                                            ^ t</span>; E = <span
                                            style="background-color:rgb(207,226,243)">A
                                            ^ t</span><br>
                                          >>> C, D, E<br>
                                          <b>(0, 0, 0)</b><br>
                                          >>> <b>A, B = 0, 1</b><br>
                                          >>> t = A | B; C = A
                                          & B; D = B ^ t; E = A ^ t<br>
                                          >>> C, D, E<br>
                                          <b>(0, 0, 1)</b><br>
                                          >>> <b>A, B = 1, 0</b><br>
                                          >>> t = A | B; C = A
                                          & B; D = B ^ t; E = A ^ t<br>
                                          >>> C, D, E<br>
                                          <b>(0, 1, 0)</b><br>
                                          >>> <b>A, B = 1, 1</b><br>
                                          >>> t = A | B; C = A
                                          & B; D = B ^ t; E = A ^ t<br>
                                          >>> C, D, E<br>
                                          <b>(1, 0, 0)</b></span><br>
                                        <br>
                                      </div>
                                      <div>Cheers,<br>
                                      </div>
                                      <div>Weston<br>
                                      </div>
                                      <br>
                                    </div>
                                    <div class="gmail_extra"><br>
                                      <br>
                                      <div class="gmail_quote">On Wed,
                                        Jan 15, 2014 at 8:42 PM, Mr.
                                        Clif <span dir="ltr"><<a
                                            moz-do-not-send="true"
                                            href="mailto:clif@eugeneweb.com"
                                            target="_blank">clif@eugeneweb.com</a>></span>
                                        wrote:<br>
                                        <blockquote class="gmail_quote"
                                          style="margin:0 0 0
                                          .8ex;border-left:1px #ccc
                                          solid;padding-left:1ex">Sure I
                                          can do it in three but two of
                                          the gates have to have one
                                          inverting input each. Since
                                          gates often come in quad packs
                                          it might be nice to find a
                                          circuit that would use all
                                          four in a pack. Though if it
                                          helps my fourth gate is just
                                          an inverter and there are
                                          often left over ones from
                                          other packages.<br>
                                          <br>
                                              Clif
                                          <div>
                                            <div><br>
                                              <br>
                                              <br>
                                              <br>
                                              <br>
                                              On 01/15/2014 07:42 PM,
                                              Weston Turner wrote:<br>
                                            </div>
                                          </div>
                                          <blockquote
                                            class="gmail_quote"
                                            style="margin:0 0 0
                                            .8ex;border-left:1px #ccc
                                            solid;padding-left:1ex">
                                            <div>
                                              <div> I'm wondering if
                                                anyone can implement
                                                this logic table with
                                                less than four gates...<br>
                                                <br>
                                                A B | C D E<br>
                                                -------------<br>
                                                0 0 | 0 0 0<br>
                                                0 1 | 0 0 1<br>
                                                1 0 | 0 1 0<br>
                                                1 1 | 1 0 0<br>
                                                <br>
                                                I figured out a way to
                                                implement it with four
                                                gates but I'm wondering
                                                if it can be reduced
                                                further...<br>
                                                <br>
                                                And if you can only
                                                figure out a way to do
                                                it with four, then I'm
                                                curious to see if you
                                                arrived at the same
                                                solution I did.<br>
                                                <br>
                                                Regards,<br>
                                                Weston<br>
                                              </div>
                                            </div>
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            <br>
            <br clear="all">
            <div><br>
            </div>
            -- <br>
            Bob Miller                              K<bob><br>
                                                    <a
              moz-do-not-send="true" href="mailto:kbob@jogger-egg.com">kbob@jogger-egg.com</a><br>
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