The Vintage HP - 35 Calculator The First Electronic Slide Rule Calculator
Item History & Price
| Reference Number: Avaluer:15597037 | Model: HP 35 |
| Features: Portable | Country/Region of Manufacture: United States |
| MPN: HP 35 | Type: Audio Cable Splitter |
| Brand: HP | UPC: Does not apply |
Description
HP-35 mainboard.The calculator used a traditional floating decimal display for numbers that could be displayed in that format, but automatically switched to scientific notation for other numbers. The fifteen-digit LED display was capable of displaying a ten-digit mantissa plus its sign and a decimal point and a two-digit exponent plus its sign. The display used a unique form of multiplexing, illuminating a single LED segment at a time rat...her than a single LED digit, because HP research had shown that this method was perceived by the human eye as brighter for equivalent power. Light emitting diodes were relatively new at the time and were much dimmer than high efficiency diodes developed in subsequent decades.
The calculator used three "AA"-sized NiCd batteries assembled into a removable proprietary battery pack. Replacement battery packs are no longer available, leaving existing HP-35 calculators to rely on AC power, or their users to rebuild the battery packs themselves using available cells. An external battery charger was available and the calculator could also run from the charger, with or without batteries installed.
Internally, the calculator was organized around a serial (one-bit) processor chipset made under contract by Mostek, processing 56-bit floating-point numbers, representing 14-digit BCD numbers.HP-35 functions Arithmetic +, −, ×, ÷Trigonometry - sin, arc sin; cos, arc cos; tan, arc tan (decimal degrees)Logarithms - log10x; logex, exOther - 1/x, √x, xy, πThe calculator had a four register stack (x, y, z and t), the 'enter' key pushed the displayed value (x) down the stack. Any binary operation popped the top two registers, and pushed the result. When the stack was popped the t register duplicated into the z register.Calculator triviaThe HP-35 was 5.8 inches (150 mm) long and 3.2 inches (81 mm) wide, said to have been designed to fit into one of William Hewlett's shirt pockets. Was the first scientific calculator to fly in space in 1972.[5] HP-35s were used on the US space station, Skylab, between May 1973 and February 1974.[6] Is the first pocket calculator with a numeric range that covered 200 decades (more precise 199, ±10±99).[5]The LED display power requirement was responsible for the HP-35's short battery life between charges — about three hours. To extend operating time and avoid wearing out the on/off slide switch, users would press the decimal point key to force the display to illuminate just a single LED junction.The HP-35 calculated arithmetic, logarithmic, and trigonometric functions but the complete implementation used only 767 carefully chosen instructions (7670 bits).One high quality feature of the HP-35 was its use of double-injected keys. Rather than printing the function on the key surface where it could wear off over time and use as with cheaper calculators, the keys were constructed with two colors of plastic, providing durable key top labels for the labeled keys. Introduction of the HP-35 and similar scientific calculators by Texas Instruments soon thereafter signaled the demise of the slide rule among science and engineering students. Slide rule holsters rapidly gave way to "electronic slide rule" holsters, and colleges began to drop slide-rule classes from their curricula.100, 000 HP-35 calculators were sold in the first year, and over 300, 000 by the time it was discontinued in 1975—3½ years after its introduction.[7]In 2007 HP introduced a revised HP 35s calculator in memory of the original.An emulation of the HP-35 is available for the Apple iPhone and iPad.
HP-35 mainboard.The calculator used a traditional floating decimal display for numbers that could be displayed in that format, but automatically switched to scientific notation for other numbers. The fifteen-digit LED display was capable of displaying a ten-digit mantissa plus its sign and a decimal point and a two-digit exponent plus its sign. The display used a unique form of multiplexing, illuminating a single LED segment at a time rat...her than a single LED digit, because HP research had shown that this method was perceived by the human eye as brighter for equivalent power. Light emitting diodes were relatively new at the time and were much dimmer than high efficiency diodes developed in subsequent decades.
The calculator used three "AA"-sized NiCd batteries assembled into a removable proprietary battery pack. Replacement battery packs are no longer available, leaving existing HP-35 calculators to rely on AC power, or their users to rebuild the battery packs themselves using available cells. An external battery charger was available and the calculator could also run from the charger, with or without batteries installed.
Internally, the calculator was organized around a serial (one-bit) processor chipset made under contract by Mostek, processing 56-bit floating-point numbers, representing 14-digit BCD numbers.HP-35 functions Arithmetic +, −, ×, ÷Trigonometry - sin, arc sin; cos, arc cos; tan, arc tan (decimal degrees)Logarithms - log10x; logex, exOther - 1/x, √x, xy, πThe calculator had a four register stack (x, y, z and t), the 'enter' key pushed the displayed value (x) down the stack. Any binary operation popped the top two registers, and pushed the result. When the stack was popped the t register duplicated into the z register.Calculator triviaThe HP-35 was 5.8 inches (150 mm) long and 3.2 inches (81 mm) wide, said to have been designed to fit into one of William Hewlett's shirt pockets. Was the first scientific calculator to fly in space in 1972.[5] HP-35s were used on the US space station, Skylab, between May 1973 and February 1974.[6] Is the first pocket calculator with a numeric range that covered 200 decades (more precise 199, ±10±99).[5]The LED display power requirement was responsible for the HP-35's short battery life between charges — about three hours. To extend operating time and avoid wearing out the on/off slide switch, users would press the decimal point key to force the display to illuminate just a single LED junction.The HP-35 calculated arithmetic, logarithmic, and trigonometric functions but the complete implementation used only 767 carefully chosen instructions (7670 bits).One high quality feature of the HP-35 was its use of double-injected keys. Rather than printing the function on the key surface where it could wear off over time and use as with cheaper calculators, the keys were constructed with two colors of plastic, providing durable key top labels for the labeled keys. Introduction of the HP-35 and similar scientific calculators by Texas Instruments soon thereafter signaled the demise of the slide rule among science and engineering students. Slide rule holsters rapidly gave way to "electronic slide rule" holsters, and colleges began to drop slide-rule classes from their curricula.100, 000 HP-35 calculators were sold in the first year, and over 300, 000 by the time it was discontinued in 1975—3½ years after its introduction.[7]In 2007 HP introduced a revised HP 35s calculator in memory of the original.An emulation of the HP-35 is available for the Apple iPhone and iPad.
