JCE Percent Calculator

Date of introduction:  1973 Display technology:  LED-modules
New price:   Display size:  8
Size:  5.5" x 3.2" x 1.65"
 139 x 82 x 42 mm3
Weight:  7.1 ounces, 202 grams Serial No:  902547
Batteries:  4*AA Date of manufacture:  
AC-Adapter:   Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0128
Program steps:   Courtesy of:  Joerg Woerner

JCE (John Collins Enterprises) located in Palo Alto, CA developed and manufactured only few portable electronic calculators around 1972. All known models (JCE Mark II, Percent, Super D) use the famous Texas Instruments Klixon keypad and sport huge 8-digit LED displays. JCE went out of the calculator business sometimes in 1973 to 1974. 

Percent_02.jpg (25499 Byte)The side-view of the JCE Percent calculator gives an idea of the convenient reading angle of the display. 

Percent_Disp.jpg (21734 Byte)The display itself uses huge, single 7-segment modules manufactured by US-based company Fairchild. 

Percent_1.jpg (49283 Byte)The TMS0128 single-chip calculator IC added to the basic functions of the original TMS1802 circuit (better known as TMS0102) the %-function. Other calculators like the Litronix Checkmate 1002 used one position of the space-limited Klixon
keyboard for the decimal switch. JCE found another solution, the switch was hidden somewhere.

Another known calculator using the TMS0128 is the Canon LE-82. Engineers in Japan just removed that switch. 

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If you have additions to the above article please email:

Joerg Woerner, October 24, 2002. No reprints without written permission.