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
|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|
|Program steps:||Courtesy of:||Joerg Woerner|
|Download manual:||(US: 2.4M Bytes)|
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: firstname.lastname@example.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.