TI SR-50
From Wikipedia, the free encyclopedia
The SR-50 was Texas Instruments' first scientific pocket calculator with trigonometric and logarithm functions. It was an update of their SR-10 of 1973 which had featured scientific notation, squares, square root, and reciprocals, but no trig or log functins. The SR-50 was introduced in 1974 and sold for US$170.[1] The SR-50 had a display with ten digits plus a two digit exponent for floating point numbers. It used ordinary infix notation, as opposed to the reverse polish notation employed by its rival, the Hewlett Packard HP-35. The SR-50 measured 5-3/4 inch long by 3-1/8 inch wide by 1-3/16 inch high (147 mm by 78 mm by 31 mm) and was powered by a rechargeable NiCad battery pack. It had 40 keys, an on/off switch and a degrees/radians switch. "SR" reportedly stood for "slide rule."
The SR-50 was followed by the programmable model SR-52 in 1975. It could perform 224 program steps recorded on magnetic cards, similar to its competitor HP-65.
