HP-65
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RPN key stroke | |
Display type | Red LED seven-segment display |
---|---|
Display size | 15 digits (decimal point uses one digit), (±10±99) |
CPU | |
Processor | proprietary |
Programming | |
Programming language(s) | key codes |
Memory register | 8 (9) plus 4-level working stack |
Program steps | 100 |
Other | |
Power supply | Internal rechargeable battery or 115/230 V AC, 5 W |
Weight | Calculator: 11 oz (310 g), recharger: 5 oz (140 g) |
Dimensions | Length: 6.0 inches (150 mm), width: 3.2 inches (81 mm), height: 0.7–1.4 inches (18–36 mm) |
The HP-65 is the first magnetic card-programmable handheld calculator. Introduced by
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 magnetic program cards are fed in at the thick end of the calculator under the LED display. The documentation for the programs in the calculator is very complete, including algorithms for hundreds of applications, including the solutions of differential equations, stock price estimation, statistics, and so forth.
Features
The HP-65 introduced the "tall", trapezoid-shaped keys that would become iconic for many generations of HP calculators. Each of the keys had up to four functions. In addition to the "normal function" printed on the key's face, a "gold" function printed on the case above the key and a "blue" function printed on the slanted front surface of the key were accessed by pushing the gold f or blue g prefix key, respectively. For example, f followed by 4 would access the sine function, or g followed by 4 would calculate . For some mathematical functions, a gold f−1 prefix key would access the inverse of the gold-printed functions, e.g. f−1 followed by 4 would calculate the inverse sine ().
Functions included square root, inverse, trigonometric (sine, cosine, tangent and their inverses), exponentiation, logarithms and factorial. The HP-65 was one of the first calculators to include a base conversion function, although it only supported octal (base 8) conversion. It could also perform conversions between degrees/minutes/seconds (
Programming
The HP-65 had a program memory for up to 100 instructions of six bits which included subroutine calls and conditional branching based on comparison of x and y registers. Some (but not all) commands entered as multiple keystrokes were stored in a single program memory cell. When displaying a program, the key codes were shown without line numbers.
A program could be saved to mylar-based magnetically coated cards measuring 71 mm × 9.5 mm (2.8 in × 0.4 in), which were fed through the reader by a small electric motor through a worm gear and rubber roller at a speed of 6 cm/s (2.4 in/s).
Cards could be write-protected by diagonally clipping the top-left corner of the card. HP also sold a number of program collections for scientific and engineering applications on sets of prerecorded (and write-protected) cards.
The HP-65 had an issue/design flaw whereby storage register R9 was corrupted whenever the user (or program) executed trigonometric functions or performed comparison tests; this kind of issue was common in many early calculators, caused by a lack of memory due to cost, power, or size considerations. Since the limitation was intended from the beginning and documented in the manual, it is not, strictly speaking, a bug.
Significant applications
During the 1975
In the same year,
See also
References
- ^ "HP Virtual Museum: Hewlett-Packard-65 programmable pocket calculator, 1974". Retrieved 2011-01-29.
- ^ 1634–1699: McCusker, J. J. (1997). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States: Addenda et Corrigenda (PDF). American Antiquarian Society. 1700–1799: McCusker, J. J. (1992). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States (PDF). American Antiquarian Society. 1800–present: Federal Reserve Bank of Minneapolis. "Consumer Price Index (estimate) 1800–". Retrieved 2024-02-29.
- ^ Taggart, Robert B. (May 1974). "Designing a Tiny Magnetic Card Reader" (PDF). Hewlett-Packard Journal. Retrieved 2019-05-01.
External links
- The HP-65 at an unofficial Hewlett-Packard museum (MyCalcDB); includes a photograph of the magnetic card.
- 1975 HP Calculator Christmas Guide
- HP's Virtual Museum: HP-65
- HP-65 page at the unofficial Museum of HP Calculators
- One of the HP-65s carried on the ASTP space flight is in the collection of the National Air and Space Museum.