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|
The 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 (COB) technology we noticed 9 small LED-modules with an additional magnifier lens. We we compiled an overview of all Exactra Calculator LED Displays.
Fellow calculator collector David Butler reported recently a Eactra 21 calculator manufactured in week 34 sporting the 9 LED-modules and we assume that Texas Instruments switched in August 1974 to Bowmar Opto-Stick and in February 1975 to COB technology.
If you have additions to the above article please email: email@example.com.
© Joerg Woerner, October 17, 2003. No reprints without written permission.