Historical BackgroundBeginning in 1961, Fairchild offered one of the first Integrated Circuit product lines for commercial sale.  These ICs were silicon and contained a few transistors, diodes, resistors and even capacitors on the silicon “chip”.  These ICs implemented basic logic functions and used a type of circuitry known as RTL (Resistor Transistor Logic). The 923 is an RTL IC containing 15 transistors which performs the logic function defined as J-K Flip-Flop.  Initial prices were quite high ($50 for example), but began to fall as more companies entered the market.  Fairchild used the copyrighted name MicroLogic® and uLogic® for their first ICs.  Your 923 units are Fairchild uLogic RTL ICs from the early 70s.  Your units are type 923EC, which indicates commercial temperature range and epoxy case.  There are eight leads on the 923, with details provided in your documentation.





Fairchild uLogic® 923

RTL Integrated Circuit

J-K Flip-Flop



Your uLogic 923 integrated circuits as shown above are 40+ years old and represent the earliest type of integrated circuits made available commercially in large quantities by Fairchild.  You can use these devices to experiment with digital logic and computer circuits, or as replacements for products sold in the 1960s and 1970s that used these unique devices.  Your historic Fairchild uLogic 923 integrated circuits are “New Old Stock” and should function as designed.






$12 per Package (Two uL 923 ICs)

Add $3.00 Shipping/Handling within U.S.


For PayPal or Check Payment

Your Transistor Museum™ uL 923 Order Will Contain:

Two New Old Stock uL 923 ICs 

 (Style Shown Above)

Transistor Museum™ Classic Semiconductor Storage

And Display Envelope, with  Informational Insert

uL 923 Historic Semiconductor

Fact Sheet

Use this Link to See the Complete  Fairchild uLogic 923 FACT SHEET

Copyright © 2012 by Jack Ward.  All Rights Reserved.