The HP-55 was a programmable handheld calculator, a lower-cost alternative to the HP-65. Introduced by Hewlett-Packard in 1975, it featured twenty storage registers and room for 49 keystroke instructions. Its outward appearance was similar to the HP-65, but its silver band went through between the display and the keyboard like HP-45, and the functions of some keys were different from HP-65, and it did not have a magnetic card reader/writer. Like all Hewlett-Packard calculators of the era and most since, the HP-55 used Reverse Polish Notation (RPN) and a four-level automatic operand stack.
Another feature of the HP-55 was that it officially featured a stop-watch function much similar to the hidden stop-watch function of the earlier HP-45 calculator. This stop-watch function could be accessed by setting the mode-slider to the Timer position. A quartz-crystal inside the calculator provided an accurate timebase, and it was advertised that the timer ran with as little as +/- 0.01% error. The data format used by the stop-watch consisted of a combination of units (Hours, Minutes and Seconds), but the HP-55 featured a special conversion function to convert between this format and a pure unit (Hours). Because of this, data from the stop-watch could easily be used right away in calculations.
The HP-55 also featured several other conversion functions to instantly convert data between the Imperial and Metric systems.
Bill Hewlett's design requirement was that the calculator should fit in his shirt pocket. That is one reason for the tapered depth of the calculator. The documentation for the programs in the calculator is complete, including algorithms for hundreds of applications, including the solutions of differential equations, stock price estimation, statistics, and so forth.
The HP-55 at an unofficial Hewlett-Packard museum (MyCalcDB).
HP-55 page at the unofficial Museum of HP Calculators
January 01, 1970
programmable, handheld, calculator, lower, cost, alternative, introduced, hewlett, packard, 1975, featured, twenty, storage, registers, room, keystroke, instructions, outward, appearance, similar, silver, band, went, through, between, display, keyboard, like, . The HP 55 was a programmable handheld calculator a lower cost alternative to the HP 65 Introduced by Hewlett Packard in 1975 it featured twenty storage registers and room for 49 keystroke instructions Its outward appearance was similar to the HP 65 but its silver band went through between the display and the keyboard like HP 45 and the functions of some keys were different from HP 65 and it did not have a magnetic card reader writer Like all Hewlett Packard calculators of the era and most since the HP 55 used Reverse Polish Notation RPN and a four level automatic operand stack HP 55HP 55 TypeProgrammableIntroduced1975CalculatorEntry modeRPNDisplay typeRed LED seven segment displayDisplay size15 digits decimal point uses one digit 10 99 ProgrammingProgramming language s RPN key strokeOtherPower supplyInternal rechargeable battery or 115 230 V AC 5 WWeightCalculator 9 oz 260 g recharger 5 oz 140 g DimensionsLength 5 8 inches 150 mm width 3 2 inches 81 mm height 0 7 1 3 inches 18 33 mm Another feature of the HP 55 was that it officially featured a stop watch function much similar to the hidden stop watch function of the earlier HP 45 calculator This stop watch function could be accessed by setting the mode slider to the Timer position A quartz crystal inside the calculator provided an accurate timebase and it was advertised that the timer ran with as little as 0 01 error The data format used by the stop watch consisted of a combination of units Hours Minutes and Seconds but the HP 55 featured a special conversion function to convert between this format and a pure unit Hours Because of this data from the stop watch could easily be used right away in calculations The HP 55 also featured several other conversion functions to instantly convert data between the Imperial and Metric systems Bill Hewlett s design requirement was that the calculator should fit in his shirt pocket That is one reason for the tapered depth of the calculator The documentation for the programs in the calculator is complete including algorithms for hundreds of applications including the solutions of differential equations stock price estimation statistics and so forth See also editHP 45 HP 65External links editThe HP 55 at an unofficial Hewlett Packard museum MyCalcDB 1975 HP Calculator Christmas Guide HP 55 page at the unofficial Museum of HP Calculators Retrieved from https en wikipedia org w index php title HP 55 amp oldid 1162489311, wikipedia, wiki, book, books, library,
