1972 · Single-Chip LED Calculator · Work 940 of 1,871
The electronics counter of a department store in Houston in summer, on a glass counter with a brass edge a hand-held calculator standing upright on a clear acrylic stand, a rounded body fourteen centimetres tall in pale tan plastic with a tall plain upper part, below it a dark brown front with a narrow slot of soft red glow, a tiny switch at the right, eighteen square cream keys and one wide orange key at the lower right, all plain smooth and unmarked, a saleswoman's hand in a short floral sleeve sliding the stand forward, a customer's forearm with a white handbag at the opposite edge, shelves and ceiling lights soft behind.
What it was used for
Texas Instruments announced the TI-2500 Datamath in April 1972 at a list price of 149.95 dollars. It had an 8-digit LED display and did the 4 basic operations with the TMS0119 chip, which held all the logic and the memory for 3 registers. Power came from 6 rechargeable AA cells giving about 4 to 6 hours of use, with charging taking 14 to 16 hours; a mains adapter was also possible. On the first version the display switched down to the first digit after about 15 seconds. The CE/D key cleared the last entry or brought the display back.
What was new
What marked it was not the technology but who sold it. In the account of the Centre for Computing History the Datamath was the first calculator TI put out under its own name, the company having until then supplied only components to other makers. With that the supplier became the competitor of its own customers: Bowmar built its machines around TI chips, lost the lead to TI and filed for bankruptcy in 1976, after prices had been plunging since 1974.
What the sources leave open: April 1972 is the date of the announcement, not of first sale. The datamath.org page, the fullest on the Datamath, could not be retrieved (redirect loop); unit numbers and places of manufacture therefore remain open here.