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HP-41
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 a ... [...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 Set, single byte character sets introduced by Hewlett-Packard since 1979. It was used in several Reverse Polish Notation, RPN HP calculator, calculators supporting the HP FOCAL, FOCAL programming language, like the HP-41C/HP-41CV, CV/HP-41CX, 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' SwissMicros DM41, DM41/SwissMicros DM41L, L, both introduced in 2015, and is implicitly supported by the SwissMicros DM42, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Calculator
Programmable calculators are calculators that can automatically carry out a sequence of operations under 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 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 manufacturers of pro ... [...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 80-series 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-71B
The HP-71B was a hand-held computer or calculator programmable in BASIC, made by Hewlett-Packard from 1984 to 1989. Description Smaller and less expensive (US$595 $525 in 1984 ≈ $990 in 2005 (seInflation Conversion Factors for Dollars) MSRP) than the preceding model HP-75, the 71B had a single-line 22-character liquid crystal display, 64K system ROM and 17.5K user memory. It operated on four AAA batteries. Four plug-in ports permitted ROM-based programs or additional user memory to be added. Separate compartments could accommodate an optional magnetic card reader and an optional HP-IL interface (HP 82401A) that could be used to connect printers, storage and electronic test equipment. The 71B was the first handheld to implement the IEEE 854-1987 radix-independent floating-point standard. Programming features included a real-time clock, programmable timers and subroutine calls with parameter passing and recursion. It was also HP's first calculator based on the ''Saturn'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calculator
An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-sized devices became available in the 1970s, especially after the Intel 4004, the first microprocessor, was developed by Intel for the Japanese calculator company Busicom. Modern electronic calculators vary from cheap, give-away, credit-card-sized models to sturdy desktop models with built-in printers. They became popular in the mid-1970s as the incorporation of integrated circuits reduced their size and cost. By the end of that decade, prices had dropped to the point where a basic calculator was affordable to most and they became common in schools. Computer operating systems as far back as early Unix have included interactive calculator programs such as dc and hoc, and interactive BASIC could be used to do calculations on most 1970s a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro-cassette
The Microcassette (often written generically as microcassette) is an audio storage medium, introduced by Olympus in 1969. It has the same width of magnetic tape as the Compact Cassette but in a cassette roughly one quarter the size. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact cassette but in a smaller package. History Microcassettes have mostly been used for recording voice. In particular, they are commonly used in dictation machines and answering machines. Microcassettes have also been used in computer data storage and to record music. For the latter purpose, devices for recording in stereo were produced in 1982 and, for higher fidelity, microcassettes using Type IV ("metal", i.e. coated with pure metal particles rather than oxide) tape were sold. This was an attempt by Olympus to cash in on the burgeoning Walkman market; one model, the Olympus SR-11, had a built-in radio and offered a stereo ... [...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] |
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 Polish notation (PN), in which operators ''precede'' their operands. It does not need any parentheses as long as each operator has a fixed number of operands. 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 Germany, was Konrad Zuse's Z3 in 1941 as well as his Z4 in 1945. The reverse Polish scheme was again proposed in 1954 by Arthur Burks, Don Warren, and Jesse Wright and was independently reinvented by Friedrich L. Bauer and Edsger W. Dijkstra in the early 1960s to reduce computer memory access and use the stack to evaluate expressions. The algorithms and notation for this scheme were extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N Battery
An N battery (or N cell) is a standard size of dry-cell battery. An N battery is cylindrical with electrical contacts on each end; the positive end has a bump on the top. The battery has a length of 30.2 mm and a diameter of 12.0 mm, and is approximately three-fifths the length of a AA battery. Overview A zinc–carbon battery in this type is designated as ''R1'' by IEC standards; likewise, an alkaline battery in this type is designated as ''LR1''. ANSI designates this battery as ''910A'' and ''910D'' for alkaline and zinc–carbon chemistries, respectively. Energizer calls this type ''E90''. Mercury batteries of the same dimensions are no longer manufactured because of their toxicity. Former mercury cells such as the Mallory RM401, Duracell RM-401, IEC-MR1, etc. were supplanted by the alkaline Kodak KN. Rechargeable N-size batteries are also available, in nickel-cadmium (''KR1'') and nickel-metal hydride (''HR1'') chemistries. However, these are far less comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components, as well as software and related services to consumers, small and medium-sized businesses ( SMBs), and large enterprises, including customers in the government, health, and education sectors. The company was founded in a one-car garage in Palo Alto by Bill Hewlett and David Packard in 1939, and initially produced a line of electronic test and measurement equipment. The HP Garage at 367 Addison Avenue is now designated an official California Historical Landmark, and is marked with a plaque calling it the "Birthplace of 'Silicon Valley'". The company won its first big contract in 1938 to provide test and measurement instruments for Walt Disney's production of the animated film ''Fantasia'', which allowed Hewlett and Packard to formally esta ... [...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] |
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. 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") even if it required multiple keystrokes to enter. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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