DATAMATH CALCULATOR MUSEUM
|Date of introduction:||October 1969||Display technology:||Fluorescent|
|New price:||$495||Display size:||8|
|Size:||9.8" x 5.4" x 2.8"|
|Weight:||3 pounds 3 ounces||Serial No:||151087|
|Batteries:||Date of manufacture:||year 1970|
|AC-Adapter:||220 V||Origin of manufacture:||Japan|
|Precision:||8||Integrated circuits:||Rockwell Rockwell NRD2256, AC2261, DC2266, AU2271, CG1121|
|Program steps:||Courtesy of:||Joerg Woerner|
If we trace the Timeline of calculating device starting from the early abacus and the Napier bones to the 20th century we get some important milestones:
|• 1820 The Arithmometer
• 1874 The Ohdner calculator
• 1884 The Comptometer
• 1948 The Curta
• 1960 The first electronic calculators based on vacuum tubes
• 1964 The first transistor based calculators
• 1965 Texas Instruments started the Cal-Tech project leading
to the first hand-held calculator prototype
• 1969 Sharp introduced with the QT-8D the first calculator using
LSI-IC's (Large-Scale-Integration Chips) manufactured by
US company Rockwell Electronics
• 1970 Sharp introduced its first battery operated desktop calculator QT-8B
• 1970 First battery operated, handheld calculators:
Busicom LE-120, Canon Pocketronic, Sanyo ICC-82D and Sharp EL-8.
• 1971 First portable, battery operated calculator using a
"Calculator-on-a-chip" appeared with the Bowmar 901B
Sharp Electronics Corporation introduced end of the year 1969 this important desktop calculator. A later version of the QT-8 (the QT-8B from 1970) included a rechargeable battery pack in order to make it portable. It is very similar to the first "really" portable, battery operated calculator, the EL-8.
Dismantling a Sharp QT-8D manufactured in 1970 reveals an
impressive design similar to the later EL-8 using one printed circuit board
(PCB) for the integrated display drivers and display module.
The display itself makes use of individual Itron fluorescent tubes with the odd trademark segmentation of early Sharp calculators.
An additional printed circuit board (PCB) hosts the brain of the calculator - the famous Rockwell chip set based on 4 larger Integrated Circuits (ICs) labeled NRD2256, AC2261, DC2266, AU2271 and a smaller clock driver labeled CG1121.
Read more about Sharp Corporation’s Calculator Innovations.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.