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Exactra 21 Prototype by Texas Instruments 

Date of introduction:  March 1974 Display technology:  LED-modules
New price:   Display size:  8
Size:  5.1" x 2.8" x 1.3"    
Weight:  7 ounces Serial No:  none
Batteries:  3*AA  Date of manufacture:  wk 09 yr 1974
AC-Adapter:   Origin of manufacture:  USA
Precision:   Integrated circuits:  TMS0803
Memories:      
Program steps:   Courtesy of:  Joerg Woerner

EX21_DISP.jpg (45644 Byte)The rare prototype of the Exactra 21 uses a different display construction compared to the later series model. Instead the cheap LED-stick we'll notice 9 small LED-modules with an additional magnifier lense.

EX21-1_PCB.jpg (66804 Byte)The printed circuit board (PCB) of the prototype is already in the final design stage. The date code found on the
TMS0803 single-chip calculator circuit indicates week 9 or early in March, 1974.


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

Joerg Woerner, October 17, 2003. No reprints without written permission.