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DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-508 PLUS
Date of introduction: | 1992 | Display technology: | LCD |
New price: | Display size: | 8 | |
Size: | 4.9" x 4.2" x 1.0" 125 x 106 x 25 mm3 |
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Weight: | 3.0 ounces, 84 grams | Serial No: | |
Batteries: | n.a. | Date of manufacture: | mth 06 year 1994 |
AC-Adapter: | Origin of manufacture: | Thailand (C) | |
Precision: | 8 | Integrated circuits: | Sharp LI3154 |
Memories: | 1 | ||
Program steps: | Courtesy of: | Joerg Woerner |
This
TI-508 PLUS was introduced in 1992 for the European market together with the
almost identical TI-1795+ for the American market.
It followed the original TI-508 and still hides the
secret why more or less identical calculators carry a "Handheld
(TI-5xx)" or "Desktop (TI-17xx)" designation.
Dismantling
this TI-508 LPUS manufactured in June 1994 by
Cal-Comp
Electronics in Thailand reveals a very simple construction centered
around a Sharp LI3154 single-chip calculator circuit soldered on a double-sided
printed circuit board (PCB) and powered by solar cells. We noticed this chip during our research about
so-called Checkbook Calculators with the Radio Shack
EC-455.
Learn more about single-chip calculator circuits used in
Account
Manager Calculators.
Inspecting the PCB of this
TI-508 PLUS calculator brought our attention to a small mark reading
SD9L1-10-1, most likely a reference to Type
Small Desktop 9. We spotted a very similar PCB-Mark already with the Radio Shack EC-2006A
and Privileg SOLAR 31 and started compiling a list of the PCB-Marks on calculators
manufactured by OEMs for Texas Instruments.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, January 12, 2004. No reprints without written permission.