HP-35

HP-35

HP-35 (1st version) scientific electronic pocket calculator
Type	Scientific
Introduced	1972
Discontinued	1975
Calculator
Entry mode	RPN
Display type	Red LED seven-segment display
Display size	15 digits (decimal point uses one digit), (±10±99)
Programming
Memory register	Four-register operational stack with one memory register.
Other
Power supply	Internal rechargeable battery or 115/230 V AC, 5 W
Weight	Calculator: 9 oz (260 g), recharger: 5 oz (140 g)
Dimensions	Length: 5.8 inches (150 mm), width: 3.2 inches (81 mm), height: 0.7–1.3 inches (18–33 mm)

The HP-35 was Hewlett-Packard's first pocket calculator and the world's first scientific pocket calculator:^[1] a calculator with trigonometric and exponential functions. It was introduced in 1972.