Hewlett Packard HP-35
Hewlett Packard HP-35
Display is scientific, 10 digits mantissa and 2 digits exponent, red LED.
Scientific, using Reverse Polish Notation (RPN) - as evidenced by the lack of an "=" key.
Main integrated circuits in this example - Mostek MK6020, MK6021, MK6022, MK6023, MK6024, which comprise three ROMs, a control and timing chip, and a register and arithmetic chip. This chip set was also second-sourced by AMI.
3.75v (3 x AA re-chargeable).
79 mm x 147 mm x 34 mm (3.1" x 5.8" x 1.4").
Introduced February 1972, cost $395 (about £165 Sterling).
Made in U.S.A. & Singapore.
The article "The HP-35 Calculator: The first Electronic Slide Rule", in the Collecting Calculators section of this site, has further information about the HP-35.
There is a very interesting article "Made in the USA ... finally" about the development of the HP-35 on Rick Furr's calculator site at http://www.public.usit.net/rfurr/hp-35.htm .
If you would like to try out the "Reverse Polish Notation" operation of a very realistic virtual HP-35 visit Neil Fraser's site at http://vv.carleton.ca/~neil/hp-35/ and download his excellent Javascript simulation.
This was the first hand-held scientific calculator. Hewlett Packard calculators were very well made, and reliable, and their electronics instruments had (still have) a very good reputation. Together with the high specification, this made their calculators the models of choice for many professionals. 300,000 HP-35 calculators were sold ("New Scientist", Feb. 1975).
While nearly all of the other calculator manufacturers concentrated on reducing the cost of their calculators, Hewlett Packard kept the cost high and increased the functionality. They introduced the HP-65, the first hand-held programmable calculator, in 1974, and they are one of the few companies to continue making calculators from the early 1970s to the present day.
