Solid Logic Technology

<h2 id="details">Details</h2>
<p>SLT used silicon planar glass-encapsulated transistors and diodes.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>
</p><p>SLT uses dual diode chips and individual transistor chips each approximately 0.025 inches (0.64 mm) square.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>: 15  The chips are mounted on a 0.5 inches (13 mm) square substrate with silk-screened resistors and printed connections. The whole is encapsulated to form a 0.5 inches (13 mm) square module. Up to 36 modules are mounted on each card, though a few card types had just discrete components and no modules. Cards plug into boards which are connected to form gates which form frames.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>: 15 
</p><p>SLT voltage levels, logic low to logic high, varied by circuit speed:<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>: 16 
</p>
High speed (5-10 ns) 0.9 to 3.0 V
Medium speed (30 ns) 0.0 to 3.0 V
Low speed (700 ns) 0.0 to 12.0 V

Steps in manufacturing Solid Logic Technology hybrid modules. The process starts with a blank ceramic wafer, 1⁄2 inch (13 mm) square. Circuits are laid down first, followed by resistive material. Pins are added, the circuits are soldered and the resistors trimmed to the desired value. Then individual transistors and diodes are added and the package is encapsulated.

<h2 id="later-developments">Later developments</h2>
<p>The same basic packaging technology (both device and module) was also used for the devices that replaced SLT as IBM gradually transitioned to the use of monolithic integrated circuits:
</p>
<ul><li>Solid Logic Dense (SLD) increased packaging density and circuit performance by mounting the discrete transistors and diodes on top of the substrate and the resistors on the bottom.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a>: 15  SLD voltages were the same as SLT.</li>
<li>Unit Logic Device (ULD) use flat-pack ceramic packages, much smaller than SLT's metal cans. Each package contains a ceramic wafer with up to four silicon dies on top, each die implementing one transistor or two diodes; and thick-film resistors underneath. ULDs were used in the <a href="/facts/Launch_Vehicle_Digital_Computer/cPcKqDsI">Launch Vehicle Digital Computer</a> and Launch Vehicle Data Adapter of the <a href="/facts/Saturn_V/WhpUEFJM">Saturn V</a> rocket.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a></li>
<li>Advanced Solid Logic Technology (ASLT) increased packaging density and circuit performance by stacking two substrates in the same package. ASLT is based on the <a href="/facts/Emitter-follower-coupled-switch/wAN1uEgH">Emitter-follower-coupled-switch</a> used with <a href="/facts/Emitter-coupled_logic/wAN1uEgH">current-steering logic</a>.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a>: 18  ASLT voltage levels were : > +235 mV is high, < -239 mV is low.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a>: 16 </li></ul>

<ul><li>Monolithic System Technology (MST) increased packaging density and circuit performance by replacing discrete transistors and diodes with one to four monolithic integrated circuits (resistors now external from the package on the module). Each MST chip holds about five circuits and is the approximate equivalent of an SLT card.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a>: 18  Circuits used <a href="/facts/NPN_transistor/9BMcGv5Q">NPN transistors</a>. MST was first introduced in January 1968 and provided improved cost/performance for IBM's System/370 product line of the 1970s.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a></li></ul>
<h2 id="gallery">Gallery</h2>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Standard_Modular_System/lNvvsvvG">Standard Modular System</a></li></ul>

<h2 id="external-links">External links</h2>

Wikimedia Commons has media related to IBM Solid Logic Technology.

<ul><li>Davis, E.M.; Harding, W.E.; Schwartz, R.S.; Corning, J.J. (April 1964). "Solid Logic Technology: Versatile, High-Performance Microelectronics". <i>IBM Journal of Research and Development</i>. 8 (2): 102–114. <a href="/facts/Doi_(identifier)/muM9Etpq">doi</a>:<a href="https://doi.org/10.1147%2Frd.82.0102">10.1147/rd.82.0102</a>. <a href="/facts/S2CID_(identifier)/ldJsHa2Y">S2CID</a> <a href="https://api.semanticscholar.org/CorpusID:13288023">13288023</a>.</li>
<li><a href="http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html">IBM's Solid Logic Technology (SLT) 1964-1968</a>, Vintage Computer Chips, includes video of automated manufacturing process</li></ul>

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

<ol>
<li id="fn:1"><p>Boyer, Chuck (April 2004). "The 360 Revolution" (PDF). IBM. p. 18. Retrieved 27 May 2018. <a href="http://www.computer-museum.ru/books/archiv/ibm36040.pdf" target="_blank">http://www.computer-museum.ru/books/archiv/ibm36040.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Davis, E.M.; Harding, W.E.; Schwartz, R.S.; Corning, J.J. (April 1964). "Solid Logic Technology: Versatile, High-Performance Microelectronics". IBM Journal of Research and Development. 8 (2): 102–114. doi:10.1147/rd.82.0102. S2CID 13288023. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
<li id="fn:7"><p>Ken Shirriff.
"A circuit board from the Saturn V rocket, reverse-engineered and explained".
2020. <a href="http://www.righto.com/2020/04/a-circuit-board-from-saturn-v-rocket.html" target="_blank">http://www.righto.com/2020/04/a-circuit-board-from-saturn-v-rocket.html</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li>
<li id="fn:8"><p>Dr. Wernher von Braun.
"Tiny Computers Steer Mightiest Rockets".
Popular Science.
Oct 1965.
p. 94-95; 206-208. <a href="https://books.google.com/books?id=4SUDAAAAMBAJ&pg=PA94" target="_blank">https://books.google.com/books?id=4SUDAAAAMBAJ&pg=PA94</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li>
<li id="fn:9"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li>
<li id="fn:10"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li>
<li id="fn:11"><p>Logic Blocks Automated Logic Diagrams SLT, SLD, ASLT, MST (PDF) 86 pages <a href="http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf" target="_blank">http://www.bitsavers.org/pdf/ibm/logic/SY22-2798-2_LogicBlocks_AutomatedLogicDiagrams_SLT,SLD,ASLT,MST_TO_Oct71.pdf</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li>
<li id="fn:12"><p>Pugh, Emerson W.; Johnson, Lyle R.; Palmer, John H. (1991). IBM's 360 and Early 370 System. MIT Press. p. 425. ISBN 9780262161237. Retrieved August 8, 2022. <a href="9780262161237" target="_blank">9780262161237</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li>
</ol>

Solid Logic Technology open-in-new

Solid Logic Technology