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
    Download manuals:   (US: 17.1 MByte)
  (DE: 10.9 MByte)

Together 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.

BusinessEdge_1.jpg (17574 Byte)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.

BusinessEdge_IC.jpg (124597 Byte)BusinessEdge_PCB.jpg (119073 Byte)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.