- TI SR-50
The SR-50 was
Texas Instruments' first scientific pocket calculatorwith trigonometricand logarithmfunctions. It was an update of their SR-10 of 1973which had featured scientific notation, squares, square root, and reciprocals, but no trig or log functions. The SR-50 was introduced in 1974and sold for US$170. [ [http://www.thocp.net/hardware/ti_calculators.htm 20 Years of Texas Instruments Consumer Products] ] The SR-50 had a display with ten digits plus a two digit exponent for floating pointnumbers. It used ordinary infix notation, as opposed to the reverse polish notationemployed 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 NiCadbattery pack. It had 40 keys, an on/off switch and a degrees/ radians switch. "SR" stood for " slide rule."
The SR-50 was followed by an updated model the SR-51. It had the same physical dimensions but added a 2nd function on most buttons. Most notable among the added functions were the ability to enter x:y pairs and do linear regression analysis on them. A further update resulted in the programmable model SR-52 in late 1975. It was twice as thick and could perform 224 program steps recorded on magnetic cards, similar to its competitor
Wikimedia Foundation. 2010.