Motorola MC14500B

<h2 id="overview">Overview</h2>
<p>MC14500B (ICU) is well-suited to the implementation of <a href="/facts/Ladder_logic/67UVVQwq">ladder logic</a>, and thus could be used to replace <a href="/facts/Relay/NQcb9usW">relay</a> systems and <a href="/facts/Programmable_logic_controller/bqh0GAdb">programmable logic controllers</a>, also intended for serial data manipulation.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> The processor supports 16 commands, operating at a frequency of 1 MHz.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> The MC14500B unit does not include a <a href="/facts/Program_counter/BxqulBRq">program counter</a> (PC); instead, a clock signal drives a separate PC chip; therefore the size of supported memory is dependent on the implementation of that chip. It was still in production in 1995.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
</p><p>The ICU architecture is similar to that of the <a href="/facts/Digital_Equipment_Corporation/ztxs6keA">DEC</a> <a href="/facts/PDP-14/ncAgsqVc">PDP-14</a> computer.
</p>
<h2 id="developers">Developers</h2>
<p>The ICU was conceived by Vern Gregory in the mid-1970s while working as an engineer in a marketing / applications group of Motorola Semiconductor Products Sector in Phoenix, Arizona, USA; Brian Dellande originated circuit and sub-routine designs, and co-wrote the manual; Ray DiSilvestro was the bench technician; Terry Malarkey provided management support.
</p><p>In the CMOS Logic Division in Austin, Texas, USA (where it was made) Phil Smith was the chip designer; Mike Hadley provided product applications support.
</p>
<h2 id="derivatives">Derivatives</h2>
<p>A form of the design served as an embedded controller in a custom automotive chip made for <a href="/facts/Nippon_Denso/BAGBVT43">Nippon Denso</a> by Motorola—Japan. 
</p><p><a href="/facts/I.P.R.S._B%C4%83neasa/5NMz8zVy">I.P.R.S. Băneasa</a> manufactured a clone of the MC14500B with the designation βP14500 in <a href="/facts/Integrated_injection_logic/6YUwQ4Rs">IIL</a> technology (rather than the original CMOS).<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>
</p>
<h2 id="notable-uses">Notable uses</h2>
<p>One of the computers known to be based on this processor is the educational <a href="http://wdr-1-bit-computer.talentraspel.de/">WDR 1</a>-bit computer (512 bits of RAM, LED, I/O, keyboard).<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a>
</p><p>A modern take, in retro style, of a computer based on this processor is the <a href="https://github.com/nicolacimmino/PLC-14500">PLC14500-Nano</a>. It is certified as Open Source Hardware <a href="https://certification.oshwa.org/pl000011.html">PL000011</a> so anyone can learn from its design and can freely build it.
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/WDR_paper_computer/NvYgmUAJ">WDR paper computer</a></li>
<li><a href="/facts/WDR_Computerclub/wBp7ahhw">WDR Computerclub</a></li>
<li><a href="/facts/NDR_computer/A5BbRYcX">NDR computer</a></li></ul>

<h2 id="further-reading">Further reading</h2>
<ul><li>Gregory, Vernon "Vern" C. (1979-05-08) [1977-01-24]. <a href="https://patentimages.storage.googleapis.com/4e/ea/42/0ecdf6ebef6592/US4153942.pdf">"Industrial control processor"</a> (PDF). <a href="/facts/Motorola,_Inc./ztqczx68">Motorola, Inc.</a> US patent 4153942A. <a href="https://web.archive.org/web/20220617104655/https://patentimages.storage.googleapis.com/4e/ea/42/0ecdf6ebef6592/US4153942.pdf">Archived</a> (PDF) from the original on 2022-06-17. Retrieved 2022-06-17. <a href="https://patents.google.com/patent/US4153942">[2]</a> (also: US 05/761,738; DE2801853A1)</li>
<li>Ludwig, Volker; Paschenda, Klaus, Remmelmann, Alexander (ed.), <i>Bit und Byte - Wir bauen einen Computer</i> [<i>Bit and Byte - We build a computer</i>] (TV series (6 parts)) (in German), <a href="/facts/Westdeutscher_Rundfunk/8jLK0Cqk">WDR-Schulfernsehen</a></li>
<li>Mueller, Dieter (2005) [2004]. <a href="http://www.6502.org/users/dieter/m14500/m14500.htm">"The famous/infamous MC14500"</a>. <a href="https://web.archive.org/web/20170803122314/http://www.6502.org/users/dieter/m14500/m14500.htm">Archived</a> from the original on 2017-08-03. Retrieved 2018-07-18.</li>
<li>Mueller, Dieter (2008). <a href="http://www.6502.org/users/dieter/a3/a3_5.htm">"MC14500 and arithmetic"</a>. <a href="https://web.archive.org/web/20170520222644/http://www.6502.org/users/dieter/a3/a3_5.htm">Archived</a> from the original on 2017-05-20. Retrieved 2018-07-18.</li>
<li>Mueller, Dieter (2008). <a href="http://www.6502.org:80/users/dieter/a3/a3_6.htm">"A MC14500 modification"</a>. <a href="https://web.archive.org/web/20170320114921/http://www.6502.org/users/dieter/a3/a3_6.htm">Archived</a> from the original on 2017-03-20. Retrieved 2018-07-18.</li></ul>
<h2 id="external-links">External links</h2>
<ul><li>Schembri, Thierry; Bizoirre, Sylvain; Boisseau, Olivier; Chauvaud, Pierre-Emmanuel. <a href="https://web.archive.org/web/20170520141901/http://www.old-computers.com/museum/computer.asp?st=1&c=834">"WDR-1-Bit Computer"</a>. <i>OLD-COMPUTERS.COM</i>. Archived from <a href="http://www.old-computers.com/museum/computer.asp?st=1&c=834">the original</a> on 2017-05-20. Retrieved 2017-05-20.</li>
<li><a href="https://en.wikichip.org/wiki/motorola/mc14500">"MC14500 - Motorola"</a>. Wikichip. <a href="https://web.archive.org/web/20170520222757/https://en.wikichip.org/wiki/motorola/mc14500">Archived</a> from the original on 2017-05-20. Retrieved 2017-05-20.</li>
<li><a href="https://web.archive.org/web/20170520223008/https://en.wikichip.org/wiki/motorola/mc14500/mc14500b">"MC14500B - Motorola"</a>. Wikichip. Archived from <a href="https://en.wikichip.org/wiki/motorola/mc14500/mc14500b">the original</a> on 2017-05-20. Retrieved 2017-05-20.</li>
<li><a href="https://en.wikichip.org/wiki/motorola/mc14500/isa">"MC14500 ISA - Motorola"</a>. Wikichip. <a href="https://web.archive.org/web/20170520223131/https://en.wikichip.org/wiki/motorola/mc14500/isa">Archived</a> from the original on 2017-05-20. Retrieved 2017-05-20.</li>
<li>Shirriff, Ken (February 2021). <a href="http://www.righto.com/2021/02/a-one-bit-processor-explained-reverse.html">"A one-bit processor explained: reverse-engineering the vintage MC14500B"</a>. <a href="https://web.archive.org/web/20220617102143/http://www.righto.com/2021/02/a-one-bit-processor-explained-reverse.html">Archived</a> from the original on 2022-06-17. Retrieved 2022-06-17.</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Gregory, Vernon "Vern" C.; Dellande, Brian; DiSilvestro, Ray; Malarkey, Terry; Smith, Phil; Hadley, Mike (1977). Motorola MC14500B Industrial Control Unit Handbook - Theory and Operation of a CMOS one-bit processor compatible with B series CMOS devices (PDF). Motorola Semiconductor Products Inc. 33-B78/8.0. Archived (PDF) from the original on 2022-02-20. Retrieved 2017-05-20. [1]  (2+iii+106+1 pages) (NB. Also available in German language under the title "Motorola MC14500B Industrial Control Unit Handbuch - Theorie und Anwendung eines Ein-Bit-CMOS-Prozessors".) <a href="http://www.bitsavers.org/components/motorola/14500/MC14500B_Industrial_Control_Unit_Handbook_1977.pdf" target="_blank">http://www.bitsavers.org/components/motorola/14500/MC14500B_Industrial_Control_Unit_Handbook_1977.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Industrial Control Unit MC14500B (PDF). Semiconductor Technical Data (revision 3 ed.). Motorola. 1995. pp. 306–313. Archived (PDF) from the original on 2017-05-20. Retrieved 2012-08-01. {{cite book}}: |work= ignored (help) <a href="http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf" target="_blank">http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Industrial Control Unit MC14500B (PDF). Semiconductor Technical Data (revision 3 ed.). Motorola. 1995. pp. 306–313. Archived (PDF) from the original on 2017-05-20. Retrieved 2012-08-01. {{cite book}}: |work= ignored (help) <a href="http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf" target="_blank">http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Industrial Control Unit MC14500B (PDF). Semiconductor Technical Data (revision 3 ed.). Motorola. 1995. pp. 306–313. Archived (PDF) from the original on 2017-05-20. Retrieved 2012-08-01. {{cite book}}: |work= ignored (help) <a href="http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf" target="_blank">http://www.brouhaha.com/~eric/retrocomputing/motorola/mc14500b/mc14500brev3.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>Cracea, Dumitru; Raiu, Dan (1990). Full Line Condensed Catalog 1990 (PDF). I.P.R.S. Băneasa. Archived (PDF) from the original on 2022-05-11. Retrieved 2022-06-17. <a href="http://yo3kxl.netxpert.ro/docs/cataloage_IPRS/FULL_LINE_CONDENSED_CATALOG%201990%20IPRS.pdf" target="_blank">http://yo3kxl.netxpert.ro/docs/cataloage_IPRS/FULL_LINE_CONDENSED_CATALOG%201990%20IPRS.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>Ludwig, Volker; Paschenda, Klaus; Schepers, Heinz; Terglane, Hermann-Josef; Grannemann, Klaus; John, Burkhard; Komar, Hermann; Meinersen, Ludwig (1986).  Written at Neuss & Recklinghausen, Germany. Fast alles über den WDR-1-Bit-Computer (PDF) (in German). Neuss, Germany: DATANorf. Archived (PDF) from the original on 2017-05-20. Retrieved 2017-05-20. <a href="http://wdr-1-bit-computer.talentraspel.de/documents/wdr_1-40.pdf" target="_blank">http://wdr-1-bit-computer.talentraspel.de/documents/wdr_1-40.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
</ol>

Motorola MC14500B open-in-new

Motorola MC14500B