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Canon Checkbook II

Date of introduction:  1985 Display technology:  LCD
New price:    Display size:  8
Size:  2.8" x 5.9" x 0.14"
 70 x 151 x 3.5 mm3
   
Weight:  2.6 ounces, 74 grams Serial No:  630407
Batteries:  1*LR55 Date of manufacture:  year 1985
AC-Adapter:   Origin of manufacture:  Japan
Precision:  8  Integrated circuits:  Toshiba T7752S
Memories:  3    
Program steps:   Courtesy of:  Joerg Woerner

Canon of Japan introduced already in 1982 with the Checkbook a portable Account Manager. We know a lot of spin offs from this design like the National Semiconductor NS-103 A, the Olivetti Chequebook, the Radio Shack EC-430 or the Texas Instruments TI-2200 II Checkwriter. 

But none of the products looks more beautiful than this Checkbook II and its twin. Due to the innovative membrane keypad its thickness is only 0.14" compared with nearly 0.30" of the original Checkbook calculator.

CheckbookII_1.jpg (79595 Byte)How was this possible? Removing the backside of the calculator gives a novel construction. Instead the usual printed circuit board (PCB) we notice a thin and flexible foil with single-sided traces.

CheckbookII_PCB.jpg (85507 Byte)The board itself uses only few components, and each one is thinner than usual. Even the Toshiba T7752S single-chip calculator circuit looks smarter than the NEC uPD1833 found inside the first Checkbook products.

 

This beauty was donated by Dale and Rhonda Hill. Thanks!

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If you have additions to the above article please email: joerg@datamath.org.

Joerg Woerner, February 19, 2004. No reprints without written permission.