The Texas Instruments TI-2500 Datamath marked TI's entry into the calculator market. It was introduced somewhere in 1972.
A lot of info about the TI-2500 can be found on the excellent site http://www.datamath.org/ (link valid 2022-12-30)
The TI-2500 is a plain four-function calculator. A switch lets the user choose between chained and constant calculatons.
The serial number table (serial number 2500-80005) at the back of my TI-2500 shows "Rev. D".
According to http://www.datamath.org/Story/Datamath_Age.htm (link valid 2023-01-09), the TI-2500 in my collection is from the second series, made between October and December 1972, in Dallas, Texas. But I am a bit puzzled because mine has four instead of six NiCad cells.
To be on the safe side the (Varta) NiCad cells (shown on the right) were taken out of this calculator. Whilst this calculator is therefore not in its original state anymore I prefer to take rechargeable batteries out because of the danger of leaking cells.
Many thanks to Mr. Huseyin Avni Cinemre from Turkey who was so kind to donate this calculator to the museum.
©2023 Ernst Mulder