CONCEPT 24 (Version 3) distributed by Zayre Corp.

Date of introduction:  October 10, 1976 Display technology:  Fluorescent
New price:  SRP $19.99 Display size:  8
Size:  5.3" x 2.9" x 0.8"
 134 x 74 x 21 mm3
Weight:  3.8 ounces, 108 grams Serial No:  C292547
Batteries:  2*AA Date of manufacture:  year 1976
AC-Adapter:   Origin of manufacture:  Hong Kong
Precision:  8 Integrated circuits:  Rockwell A5901CA
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Zayre Corporation was founded in 1956 by Stanley and Sumner Feldberg in Hyannis, Massachusetts as a discount department store chain. Zayre launched already in August 1975 the CONCEPT series of portable electronic calculators with the introduction of their first CONCEPT 24.

The Zayre CONCEPT Calculator Series culminated in June 1976 with the introduction of the Texas Instruments CONCEPT I, CONCEPT II, and CONCEPT III calculators based on the TI-1200, TI-1250, resp. SR-16 II but disappeared already in August 1979 with the clearance sales of the CONCEPT COMPACT calculators.

The CONCEPT 24 calculator in its 3rd design, aka Style 8161, looks familiar to us and we think immediately about the Canon Palmtronic 8M, i.e. the LD-8M 3. But comparing the two calculators side-by-side proofs easily that the CONCEPT 24 is an original design of an unknown OEM (original equipment manufacturer) in Hong Kong.

Concept-24_V3_PCB.jpg (372565 Byte)Concept-24_V3_PCB1.jpg (140747 Byte)We are eager to discover the true manufacturer of this CONCEPT 24 Version 3 calculator and decided to disassemble it completely. Not really difficult, the calculator doesn't use any screws, everything is snapped-together. The backside of the main printed circuit board (PCB) lists just a PCB identifier and the logo of the PCB manufacturer, not helpful for us. The keyboard assembly list a company named ETCO and a useless number of a patent application. The AW280 designator could be a model number of the calculator but we aren't sure about it.

Concept-24_V3_IC.jpg (121847 Byte)Concept-24_V3_PCB2.jpg (231638 Byte)The final step of removing the main PCB shows a nice layout centered around a Rockwell A5901CA single-chip calculator circuit but didn't reveal what we were looking for. Another "unknown" CONCEPT calculator, sold as Privileg Super 50 in Germany.

The 3rd design of the CONCEPT 24 calculator was introduced in October 1976 and discontinued already in January 1977 with the blow-out sales of the CONCEPT I, CONCEPT II, CONCEPT 10 and even the 2nd design of the CONCEPT 24 calculators.

Fellow collectors - if you own a Zayre CONCEPT calculator,  please report us the serial number and date code from the back of the calculator for our Database.

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If you have additions to the above article please email:

Joerg Woerner, February 5, 2010. No reprints without written permission.