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The Texas Instruments SR-40 — TI’s Scientific Calculator
The Texas Instruments SR-40 was a scientific calculator from TI’s SR (Slide Rule) series — the product line that established Texas Instruments as a major calculator manufacturer in the early-to-mid 1970s. TI’s SR series competed directly with Hewlett-Packard’s scientific calculators, offering trigonometric, logarithmic, and exponential functions that made them indispensable tools for science and engineering students. Texas Instruments’ aggressive pricing strategy made scientific calculators accessible to a broader range of students than HP’s more expensive but technically superior RPN calculators, helping establish TI’s dominant position in the educational calculator market.