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HP-41C
The HP-41C series are programmable, expandable, continuous memory handheld RPN calculators made by Hewlett-Packard from 1979 to 1990. The original model, HP-41C, was the first of its kind to offer alphanumeric display capabilities. Later came the HP-41CV and HP-41CX, offering more memory and functionality. The alphanumeric "revolution" The alphanumeric LCD screen of the HP-41C revolutionized the way a pocket calculator could be used, providing user friendliness (for its time) and expandability (keyboard-unassigned functions could be spelled out alphabetically). By using an alphanumeric display, the calculator could tell the user what was going on: it could display error messages, such as showing ("DATA ERROR") upon attempting to divide by zero instead of simply displaying a blinking zero; it could also specifically prompt the user for arguments ("ENTER RADIUS") instead of just displaying a question mark. Earlier calculators needed a key, or key combination, for every av ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-41CV Calculator
The HP-41C series are programmable, expandable, continuous memory handheld RPN calculators made by Hewlett-Packard from 1979 to 1990. The original model, HP-41C, was the first of its kind to offer alphanumeric display capabilities. Later came the HP-41CV and HP-41CX, offering more memory and functionality. The alphanumeric "revolution" The alphanumeric LCD screen of the HP-41C revolutionized the way a pocket calculator could be used, providing user friendliness (for its time) and expandability (keyboard-unassigned functions could be spelled out alphabetically). By using an alphanumeric display, the calculator could tell the user what was going on: it could display error messages, such as showing ("DATA ERROR") upon attempting to divide by zero instead of simply displaying a blinking zero; it could also specifically prompt the user for arguments ("ENTER RADIUS") instead of just displaying a question mark. Earlier calculators needed a key, or key combination, for every avai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FOCAL Character Set
In computing FOCAL character set refers to a group of 8-bit single byte character sets introduced by Hewlett-Packard since 1979. It was used in several RPN calculators supporting the FOCAL programming language, like the HP-41C/ CV/ CX as well as the later HP-42S, which was introduced in 1988 and produced up to 1995. As such, it is also used by SwissMicros' DM41/ L, both introduced in 2015, and is implicitly supported by the DM42, introduced in 2017 (although the later calculator utilizes Free42, which is based on Unicode internally). Character set The character set is derived from ASCII, but with the control code range and some high bit characters replaced by various special characters. When Hewlett-Packard introduced the HP-42S in 1988, the FOCAL character set was revised to include more characters, including a number of characters already provided by the HP 82240A infrared thermo printer, which had been introduced in 1986, as part of its extended variant of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Calculator
Programmable calculators are calculators that can automatically carry out a sequence of operations under the control of a stored computer programming, program. Most are Turing complete, and, as such, are theoretically general-purpose computers. However, their user interfaces and programming environments are specifically tailored to make performing small-scale numerical computations convenient, rather than for general-purpose use. The first programmable calculators such as the IBM CPC used punched cards or other media for program storage. Hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, flash memory, or in battery-backed read/write memory. Since the early 1990s, most of these flexible handheld units belong to the class of graphing calculators. Before the mass-manufacture of inexpensive dot-matrix LCDs, however, programmable calculators usually featured a one-line numeric or alphanumeric display. The Big Four manufacturer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-IL
The HP-IL (''Hewlett-Packard Interface Loop'') was a short-range interconnection bus or network introduced by Hewlett-Packard in the early 1980s. It enabled many devices such as printers, plotters, displays, storage devices (floppy disk drives and tape drives), test equipment, etc. to be connected to programmable calculators such as the HP-41C, HP-71B and HP-75C/D, the Series 80 and HP-110 computers, as well as generic ISA bus based PCs. Principles As its name implies, an HP-IL network formed a loop (i.e. it was a Ring network): each device in the loop had a pair of two-wire connections, one designated ''in'', which received messages from the previous device in the loop; and one designated ''out'', which delivered messages to the next device in the loop. One device on the loop is designated the ''controller'', and manages all other devices on the loop. HP-IL cables utilize a unique two-pin connector design with polarizing D-shaped shells, and can be connected together withou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Polish Notation
Reverse Polish notation (RPN), also known as reverse Łukasiewicz notation, Polish postfix notation or simply postfix notation, is a mathematical notation in which operators ''follow'' their operands, in contrast to prefix or Polish notation (PN), in which operators ''precede'' their operands. The notation does not need any parentheses for as long as each operator has a fixed number of operands. The term ''postfix notation'' describes the general scheme in mathematics and computer sciences, whereas the term ''reverse Polish notation'' typically refers specifically to the method used to enter calculations into hardware or software calculators, which often have additional side effects and implications depending on the actual implementation involving a stack. The description "Polish" refers to the nationality of logician Jan Łukasiewicz, who invented Polish notation in 1924. The first computer to use postfix notation, though it long remained essentially unknown outside of G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-67
The HP-67 is a magnetic card-programmable handheld calculator, introduced by Hewlett-Packard in 1976 at an MSRP of $450. A desktop version with built-in thermal printer was sold as the HP-97 at a price of $750. Collectively, they are known as the HP-67/97. Marketed as improved successors to the HP-65, the HP-67/97 were based on the technology of the "20-series" of calculators ( HP-25, HP-19C etc.) introduced a year earlier. The two models are functionally equivalent, and programs on magnetic cards can be interchanged between them. Features The 67/97 provide a complete set of scientific, statistical and engineering operations, including trigonometric, logarithmic and exponential functions, coordinate conversions, average/standard deviation etc. The HP-67/97 series featured a program memory of 224 eight-bit words. The two extra bits per word compared to the HP-65's six allowed the designers to store any program instruction in a single memory cell ("fully merged keycodes") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dot Matrix
A dot matrix is a 2-dimensional patterned Array data structure, array, used to represent characters, symbols and images. Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and printers. The system is also used in textiles with sewing, knitting and weaving. An alternate form of information display using lines and curves is known as a vector display, was used with early computing devices such as air traffic control radar displays and pen-based plotters but is no longer used. Electronic vector displays were typically monochrome only, and either leave the interiors of closed vector shapes unfilled, or perform slow, time-consuming and often non-uniform shape-filling, as on pen-based plotters. In printers, the dots are usually the darkened areas of the paper. In displays, the dots may light up, as in an light-emitting diode, LED, cathode-ray tube, CRT, or plasma display, or darken, as in an liquid crystal display, LCD. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharp PC-1211
The Sharp PC-1211 is the first pocket computer ever released, marketed by Sharp Corporation in March 1980. The computer was powered by two 4-bit computing, 4-bit CPUs laid out in power-saving CMOS circuitry. One acted as the main CPU, the other dealt with the input/output and display interface. Users could write computer programs in BASIC. A badge-engineered version of the PC-1211, the TRS-80 Pocket Computer (model PC-1), was marketed by Radio Shack in July 1980 as the first iteration of the TRS-80 Pocket Computer with just a marginally different look (outer plastic parts in black, not brown, gray display frame) Technical specifications *24 digit dot matrix LCD *Full QWERTY-style keyboard *Integrated beeper *Connector for printer and tape drive *Programmable in BASIC *Uses four MR44 Mercury button cells *Battery life in excess of 200 hours *1424 program steps, 26 permanent variable locations (- or -) and 178 variables shared with program steps *Built out of off-the-shelf CMOS comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharp Electronics
is a Japanese electronics company. It is headquartered in Sakai, Osaka, and was founded by Tokuji Hayakawa in 1912 in Honjo, Tokyo, and established as the Hayakawa Metal Works Institute in Abeno-ku, Osaka, in 1924. Since 2016, it is majority owned by the Taiwan-based manufacturer Hon Hai Precision Industry Co., Ltd., better known as Foxconn. Sharp makes and has made throughout its history various different consumer electronic products, including kitchen appliances such as microwave ovens, cookers, washing machines and refrigerators; home appliances such as solar cells, vacuum cleaners, air purifiers and lighting; home and office devices such as printers, computer displays, TV sets, camcorders, VCRs, as well as calculators and various audio products such as radios, audio systems and wireless speakers. Sharp's net sales reached 2.55 trillion yen in fiscal year 2022 (ending 29 February 2024), according to Statista. This represents a slight increase from the previous year's f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-emitting Diode
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seven Segment Display
A seven-segment display is a display device for Arabic numerals, less complex than a device that can show more characters such as dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information. History Seven-segment representation of figures can be found in patents as early as 1903 (in ), when Carl Kinsley invented a method of telegraphically transmitting letters and numbers and having them printed on tape in a segmented format. In 1908, F. W. Wood invented an 8-segment display, which displayed the number 4 using a diagonal bar (). In 1910, a seven-segment display illuminated by incandescent bulbs was used on a power-plant boiler room signal panel. They were also used to show the dialed telephone number to operators during the transition from manual to automatic telephone dialing. They did not achieve widespread use until the advent of LEDs in the 1970s. Some e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourteen Segment Display
A fourteen-segment display (FSD) (sometimes referred to as a starburst display or Union Jack display) is a type of display based on 14 segments that can be turned on or off to produce letters and numerals. It is an expansion of the more common seven-segment display, having an additional four diagonal and two vertical segments with the middle horizontal segment broken in half. A seven-segment display suffices for numerals and certain letters, but unambiguously rendering the ISO basic Latin alphabet requires more detail. A slight variation is the sixteen-segment display which allows additional legibility in displaying letters or other symbols. A decimal point or comma may be present as an additional segment, or pair of segments; the comma (used for triple-digit groupings or as a decimal separator in many regions) is commonly formed by combining the decimal point with a closely 'attached' leftwards-descending arc-shaped segment. Electronic alphanumeric displays may use LEDs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
