|
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] |
Hp-97 Front-2
The HP-67 is a magnetic card-programmable handheld calculator, introduced by Hewlett-Packard in 1976 at an list price, 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 trigonometry, trigonometric, logarithm, logarithmic and exponential function, exponential functions, coordinate conversions, average/standard deviation etc. The HP-67/97 series featured a program memory of 224 eight-bit computer word, words. The two extra bits per word compared to the HP-65's six allowed the designers to store any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
TI-59 / TI-58
The TI-59 is an early programmable calculator, that was manufactured by Texas Instruments from 1977. It is the successor to the TI SR-52, quadrupling the number of "program steps" of storage, and adding "ROM Program Modules" (an insertable ROM chip, capable of holding 5000 program steps). Just like the SR-52, it has a magnetic card reader for external storage. One quarter of the memory is stored on each side of one card. The TI-58 (May 1977), and later TI-58C (1979), are cut-down versions of the TI-59, lacking the magnetic card reader and having half the memory, but otherwise identical. Although the TI-58C uses a different chip than the TI-58, the technical data remain identical. The "C" in a TI (or Hewlett-Packard) model name indicates that the calculator has a ''constant'' memory (or continuous memory, respectively) allowing retention of programs and data when turned off. These calculators use a parenthesized infix calculation system called " Algebraic Operating System" (AOS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP-25
The HP-25 was a hand-held programmable scientific/engineering calculator made by Hewlett-Packard between early January 1975 and 1978. The HP-25 was introduced as a cheaper (US$195 MSRP) alternative to the ground-breaking HP-67. Similar to the way the HP-55 was a cheaper alternative to the HP-65. To reduce cost, the HP-25 omitted the HP-67's magnetic card reader, so it could only be programmed using the keyboard. After switching off, the program was lost and had to be typed in again. The model HP-25C, introduced in 1976, addressed that shortcoming through the first use of battery-backed CMOS memory in a calculator, termed ''continuous memory'' by HP. Like all early HP calculators, the 25 used the Reverse Polish Notation (RPN) for entering calculations, working on a four-level stack (x,y,z,t). Nearly all buttons had two alternative functions, accessed by a blue and yellow prefix key. A small sliding switch was used to change between "run" and "program" mode. The HP-25 used a 10-d ... [...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-65
The HP-65 is the first magnetic card-programmable handheld calculator. Introduced by Hewlett-Packard in 1974 at an MSRP of $795 (), it featured nine storage registers and room for 100 keystroke instructions. It also included a magnetic card reader/writer to save and load programs. Like all Hewlett-Packard calculators of the era and most since, the HP-65 used Reverse Polish Notation (RPN) and a four-level automatic operand stack. 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 iconi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Function
In applied mathematics, comparison functions are several classes of continuous functions, which are used in stability theory to characterize the stability properties of control systems as Lyapunov stability, uniform asymptotic stability etc. Let C(X,Y) be a space of continuous functions acting from X to Y. The most important classes of comparison functions are: : \begin \mathcal &:= \left\ \\ pt\mathcal &:= \left\\\ pt\mathcal_\infty &:=\left\\\ pt\mathcal &:=\\\ pt\mathcal &:= \left\ \end Functions of class are also called ''positive-definite functions''. One of the most important properties of comparison functions is given by Sontag’s -Lemma, named after Eduardo Sontag. It says that for each \beta \in and any \lambda>0 there exist \alpha_1,\alpha_2 \in : Many further useful properties of comparison functions can be found in.C. M. Kellett. A compendium of comparison function results. ''Mathematics of Control, Signals, and Systems'', 26(3):339–374, 2014. Comparison ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motherboard
A motherboard, also called a mainboard, a system board, a logic board, and informally a mobo (see #Nomenclature, "Nomenclature" section), is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit (CPU) and computer memory, memory, and provides connectors for other peripherals. Unlike a backplane, a motherboard usually contains significant sub-systems, such as the CPU, the chipset's input/output and Memory controller, memory controllers, interface (computing), interface connectors, and other components integrated for general use. Nomenclature ''Oxford English Dictionary'' traces the origin of the word ''motherboard'' to 1965, its earliest-found attestation occurring in the magazine ''Electronics (magazine), Electronics''. The term alludes to its importance and size compared to the components attached to i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Head
''Tape Head'' is the seventh studio album by American rock band King's X, released in 1998 via Metal Blade Records. A music video was made for the song "Fade". "World" is a reworked song from the band's ''Sneak Preview'' demos. The controversial unreleased track "Quality Control" is included on the album, but has been re-titled to "Happy". The majority of the lyrics are now different, including the lack of profanity. The album cover picture is that of Doug Pinnick wrapped in recording tape. According to Pinnick, he brought the songs "Happy", "Cupid" and "Hate You", and Ty Tabor brought "Ocean" to the ''Tape Head'' recording sessions. All other songs were band created during the recording session. The song "Walter Bela Farkas" was recorded live August 8, 1996, at the Tramps nightclub in New York City. Track listing All songs written by King's X. Personnel * Doug Pinnick – bass, vocals * Ty Tabor – guitar, vocals * Jerry Gaskill – drums, vocals Additional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PPC Journal
''PPC Journal'' was an early hobbyist computer magazine, originally targeted at users of HP's first programmable calculator, the HP-65. It originated as ''65 Notes'' and the first issue was published in 1974. It later changed names in 1978 to ''PPC Journal'' and in 1980 to ''PPC Calculator Journal''. With Volume 12 published in 1984 the magazine was renamed ''PPC Journal''. The magazine ended publication in July 1987 (Volume 14). The founder of the ''PPC'' (Personal Programming Center) and editor of the journal was Richard J. Nelson. This hobbyist group worked around the journal and was known because Nelson discovered hidden instructions on the HP-65 calculator. Later the club and the journal got maximum notoriety when several club members discovered the " synthetic instructions" of the HP-41C. Competition A similar journal since 1976 was ''52-Notes'' for the Texas Instruments Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after the commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is divided into a wide range of different fields, including computer engineering, systems engineering, power engineering, telecommunications, radio-frequency engineering, signal processing, instrumentation, photovoltaic cells, electronics, and optics and photonics. Many of these disciplines overlap with other engineering branches, spanning a huge number of specializations including hardware engineering, power electronics, Electromagnetism, electromagnetics and waves, microwave engineering, nanotechnology, electrochemistry, renewable energies, mechatronics/control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Engineering
Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural element, structural components of buildings, and railways. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to Fortune Global 500, ''Fortune'' Global 500 companies. History Civil engineering as a discipline Civil engineering is the application of physical and scientific principles for solv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
