DATAMATH CALCULATOR MUSEUM
Exactra 21 Prototype by Texas Instruments
|Date of introduction:||July 1974||Display technology:||LED-modules|
|New price:||Display size:||8|
|Size:|| 5.1" x 2.9" x 1.3"
130 x 74 x 34 mm3
|Weight:||5.1 ounces, 144 grams||Serial No:||none|
|Batteries:||3*AA||Date of manufacture:||wk 09 yr 1974|
|AC-Adapter:||Origin of manufacture:||USA|
|Program steps:||Courtesy of:||Joerg Woerner|
rare prototype of the Exactra 21 uses a different
display construction compared to the later series model. Instead the cheaper
Bowmar Opto-Stick or LED display with Chip-on-Board technology we noticed 9 small LED-modules with an additional magnifier lens. We we compiled an overview of all
Exactra Calculator LED Displays.
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 a manufacturing date of week 9 or early in March 1974.
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© Joerg Woerner, October 17, 2003. No reprints without written permission.