DATAMATH CALCULATOR MUSEUM |
Texas Instruments TI-2500B / Datamath
Date of introduction: | January 1974 | Display technology: | LED-stick w/o lens |
New price: | $69.95 | Display size: | 8 |
Size: | 5.5" x 3.0" x 1.7" 139 x 76 x 42 mm3 |
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Weight: | 6.7 ounces, 191 grams | Serial No: | 2500B487035 |
Batteries: | 3*AA NiCd or 4*AA Alkaline | Date of manufacture: | |
AC-Adapter: | AC9130 or AC9120 | Origin of manufacture: | USA |
Precision: | Integrated circuits: | TMS0119 | |
Memories: | |||
Program steps: | Courtesy of: | Joerg Woerner | |
Download manual: | (US: 2.4M Bytes) |
The
Datamath TI-2500B could be easily recognized at the nice battery compartment on the
bottom. This calculator uses either 3 rechargeable NiCd batteries or 4 alkaline cells.
Dismantling the TI-2500B reveals a small switch to disconnect the charging
current from the alkaline batteries. At a first glance the use of either 3 NiCd
batteries (3*1.2V=3.6V) or 4 alkaline batteries (4*1.5V=6.0V) looks stupid.
Thinking about the high cost price of rechargeable batteries in 1974 gives the
answer.
The only known difference to the Version 3 of the Datamath is the letter
"B" in the name and serial number. This could be a hint to the LED-display manufactured by Bowmar
and marked Opto-Stick. Don't miss the first prototypes
of the TI-2500B.
In October 1973 with the TI-2510 a
Datamath with absence of rechargeable batteries was introduced.
A more detailed comparison between the ten known Datamath Versions could be found here.
In Spain a TI-2500B was manufactured with only 3 batteries under the hood.
A similar calculator to this TI-2500B was sold under the label of Longines Symphonette. View here.
Datamath™ is a trademark of Texas Instruments.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.