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 AC2261, AU2271, DC2266, NRD2256|
|Program steps:||Courtesy of:||Joerg Woerner|
If we trace the Time-line 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
• 1969 Sharp introduced the 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.
Do get an impression about the valuable internal construction just take your time and watch the next five pictures carefully.
|This photo gives you an idea of the sleek design of the calculator.|
|The display uses its own printed circuit board with the driving electronics.|
|The display is made from single tubes with odd segmentation.|
|The printed circuit board of the calculator brain shows the famous chip-set developed by US company Rockwell. The same chips are used in the smaller EL-8.|
|An impressive view of one of the Rockwell calculator chips. Only Rockwell used the staggered layout of the pins. The datecode 7025 on top of the gold hood gives a manufacturing date mid of 1970.|
Read more about Sharp Corporation’s Calculator Innovations.
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© Joerg Woerner, December 5, 2001. No reprints without written permission.