DATAMATH CALCULATOR MUSEUM
Texas Instruments Business Edge
|Date of introduction:||1988||Display technology:||LCD Touchscreen|
|New price:||$60.00 (SRP 1988)||Display size:||10 (7+2)|
|Size:|| 5.8" x 2.9" x 0.5"
147 x 75 x 12 mm≥
|Weight:||3.7 ounces, 104 grams||Serial No:|
|Batteries:||Date of manufacture:||mth 01 year 1988|
|AC-Adapter:||Origin of manufacture:||Taiwan (I)|
|Precision:||13||Integrated circuits:||Toshiba T9728|
|Program steps:||Courtesy of:||Joerg Woerner|
(US: 17.1 MByte)
(DE: 10.9 MByte)
with the FIA-10 the Business Edge established a new human
interface within the calculator line of Texas Instruments. Both supported
function keys with different meaning.
The Business Edge features five pressure-sensitive areas on the LCD-screen and displays the actual function under these squares. The remaining functionality could be compared with other Financial calculators like the BA-35.
Dismantling this Business Edge manufactured in January 1988 by Inventec Corporation in Taiwan is a serious task because the printed circuit board (PCB) is molded down to the housing with small pins. We opened the housing nevertheless and traced down to a Toshiba T9728 single-chip calculator circuit connected with a small flexible cable to the 5 touch keys.
Inspecting the PCB of this Business Edge calculator brought our attention to a small mark reading IOST412-31D, we noticed similar marks already with other calculators manufactured by Inventec Corporation and started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.
The concept of variable function keys was later used on all Graphing calculators like the TI-81.
A similar financial calculator was introduced with Personal Banker featuring Help Cards.
Compare the Business Edge with its close relative EC-5500 sold by Radio Shack.Don't miss the APOTHECALC computer using a similarrsingle-chip calculator circuit for a completely different application.single-chip calculator circuit for a completely different application.
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© Joerg Woerner, December 5, 2001. No reprints without written permission.