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HP2640
The HP 2640A and other HP 264X models were block-mode "smart" and intelligent ASCII standard serial Computer terminal, terminals produced by Hewlett-Packard using the Intel 8008 and Intel 8080, 8080 microprocessors. History The HP 2640A was introduced in November 1974 at a list price of US$3000. Based on the Intel 8008 CPU, it had 8 KB of ROM firmware and came standard with 1 KB of RAM, expandable up to 8 KB (two 4 KB semiconductor RAM cards). In September 1975 Hewlett-Packard introduced the HP 2644A, which was an HP 2640A with mass storage (two mini-tape cartridges, 110 KB each), for US$5000. HP followed up in 1976 with the 2640B, an updated, cost-reduced version of the 2640A with a list price of US$2600, along with three international versions: the Cyrillic-oriented 2640C, the Swedish/Finnish-oriented 2640S, and the Danish/Norwegian-oriented 2640N. All of these early members of the 2640 series had the relatively slow 8008 CPU running at 700 kHz, and they were thus limited to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP 9800 Series
The HP 9800 is a family of what were initially called programmable calculators and later desktop computers that were made by Hewlett-Packard, replacing their first HP 9100 calculator. It is also named "98 line". The 9830 and its successors were true computers in the modern sense of the term, complete with a powerful BASIC language interpreter. Models Second generation Chronologically, the models of the family were: * HP 9810A, a keystroke programmable computer with magnetic cards and LED display, introduced in 1971, * HP 9820A, introduced in 1972, was the first HP model that deals with algebraic input (not only RPN) featured a high level language simpler than BASIC that was later named HP 9800 series#HPL, high performance language (HPL), * HP 9821A, similar to the HP 9820A, however, with Compact Cassette tape drive with clear leaders instead of using magnetic cards. Tapes created on the HP 9821A could be read by the HP 9830A. Unlike later home computers which used standard c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Survey65 (38349185954)
Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the ice crystals form in the atmosphere, increase to millimeter size, precipitate and accumulate on surfaces, then metamorphose in place, and ultimately melt, slide, or sublimate away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, which freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns, and rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow metamorphoses, by sintering, sublimation, and freeze-thaw. Where the clima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP 2100
The HP 2100 is a series of 16-bit minicomputers that were produced by Hewlett-Packard (HP) from the mid-1960s to early 1990s. Tens of thousands of machines in the series were sold over its 25-year lifetime, making HP the fourth-largest minicomputer vendor during the 1970s. The design started at Data Systems Inc (DSI), and was originally known as the DSI-1000. HP purchased the company in 1964 and merged it into their Dymec division. The original model, the 2116A built using integrated circuits and magnetic-core memory, was released in 1966. Over the next four years, models A through C were released with different types of memory and expansion, as well as the cost-reduced 2115 and 2114 models. All of these models were replaced by the HP 2100 series in 1971, and then again as the 21MX series in 1974 when the magnetic-core memory was replaced with semiconductor memory. All of these models were also packaged as the HP 2000 series, combining a 2100-series machine with optional compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HP 300
The HP 300 "Amigo" was a computer produced by Hewlett-Packard (HP) in the late 1970s based loosely on the stack-based HP 3000, but with virtual memory for both code and data. The HP300 was cut-short from being a commercial success despite the huge engineering effort, which included HP-developed and -manufactured silicon on sapphire (SOS) processor and I/O chips. The HP300 was initially designed as a single-user workstation by a totally separate program within the General Systems Division (GSD), the Cupertino, California home of the HP 3000 business computers (the division was later renamed Computer Systems Division CSY). Later, the HP300 design team developed multi-user abilities, and an ahead of its time inter-unit processor interconnect that let one HP300 change registers in other inter-connected HP300's system. Features The circuit boards were in a floor pedestal box, with CRT on top with built-in soft keys, and fixed keyboard protruding in front. It pioneered such ideas as bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screen-labeled Function Keys
A soft key is a button flexibly programmable to invoke any of a number of functions rather than being associated with a single fixed function or a fixed set of functions. A softkey often takes the form of a screen-labeled function key located alongside a display device, where the button invokes a function described by the text at that moment shown adjacent to the button on the display. Soft keys are also found away from the display device, for example on the sides of cellular phones, where they are typically programmed to invoke functions such as PTT, memo, or volume control. Function keys on keyboards are a form of soft key. In contrast, a hard key is a key with dedicated function such as the keys on a number keypad. Screen-labeled function keys are today most commonly found in kiosk applications, such as automated teller machines and gas pumps. Screen-label function keys date to aviation applications in the late 1960s. Kiosk applications were particularly common in the 1990s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point (telecommunications), point-to-point and point-to-multipoint communication, point-to-multipoint configurations. Initially, from 1887 at the earliest, teleprinters were used in telegraphy. Electrical telegraphy had been developed decades earlier in the late 1830s and 1840s, then using simpler Morse key equipment and telegraph operators. The introduction of teleprinters automated much of this work and eventually largely replaced skilled labour, skilled operators versed in Morse code with Data entry clerk, typists and machines communicating faster via Baudot code. With the development of early computers in the 1950s, teleprinters were adapted to allow typed data to be sent to a computer, and responses printed. Some teleprinter models could also be used to create punched tape for Compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bit-paired Keyboard
A bit-paired keyboard is a keyboard where the layout of shifted keys corresponds to columns in the ASCII (1963) table, archetypally the Teletype Model 33 (1963) keyboard. This was later contrasted with a typewriter-paired keyboard, where the layout of shifted keys corresponds to ''electric'' typewriter layouts, notably the IBM Selectric (1961). The difference is most visible in the digits row (top row): compared with mechanical typewriters, bit-paired keyboards remove the _ character from 6 and shift the remaining &*() from 7890 to 6789, while typewriter-paired keyboards replace 3 characters: from " to @ from _ to ^ and from ' to *. An important subtlety is that ASCII was based on mechanical typewriters, but electric typewriters became popular during the same period that ASCII was adopted, and made their own changes to layout. Thus differences between bit-paired and (electric) typewriter-paired keyboards are due to the differences of both of these from earlier mechanical ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Function Key
A function key is a key on a computer or computer terminal, terminal computer keyboard, keyboard that can be programmed to cause the operating system or an application program to perform certain actions, a form of soft key. On some keyboards/computers, function keys may have default actions, accessible on power-on. Function keys on a terminal may either generate short fixed sequences of characters, often beginning with the escape character (ASCII 27), or the characters they generate may be configured by sending special character sequences to the terminal. On a standard computer keyboard, the function keys may generate a fixed, single byte code, outside the normal ASCII range, which is translated into some other configurable sequence by the keyboard device driver or interpreted directly by the application program. Function keys may have abbreviations or pictographic representations of default actions printed on/besides them, or they may have the more common "F-number" designatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Keyboard
A computer keyboard is a built-in or peripheral input device modeled after the typewriter keyboard which uses an arrangement of buttons or Push-button, keys to act as Mechanical keyboard, mechanical levers or Electronic switching system, electronic switches. Replacing early punched cards and paper tape technology, interaction via teleprinter-style keyboards have been the main input device, input method for computers since the 1970s, supplemented by the computer mouse since the 1980s, and the touchscreen since the 2000s. Keyboard keys (buttons) typically have a set of characters Engraving, engraved or Printing, printed on them, and each press of a key typically corresponds to a single written symbol. However, producing some symbols may require pressing and holding several keys simultaneously or in sequence. While most keys produce character (computing), characters (Letter (alphabet), letters, Numerical digit, numbers or symbols), other keys (such as the escape key) can prompt the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode-ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms on an oscilloscope, a Film frame, frame of video on an Analog television, analog television set (TV), Digital imaging, digital raster graphics on a computer monitor, or other phenomena like radar targets. A CRT in a TV is commonly called a picture tube. CRTs have also been Williams tube, used as memory devices, in which case the screen is not intended to be visible to an observer. The term ''cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT TVs and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster scan, raster. In color devices, an image is produced by con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3 Aspect Ratio
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious and cultural significance in many societies. Evolution of the Arabic digit The use of three lines to denote the number 3 occurred in many writing systems, including some (like Roman and Chinese numerals) that are still in use. That was also the original representation of 3 in the Brahmic (Indian) numerical notation, its earliest forms aligned vertically. However, during the Gupta Empire the sign was modified by the addition of a curve on each line. The Nāgarī script rotated the lines clockwise, so they appeared horizontally, and ended each line with a short downward stroke on the right. In cursive script, the three strokes were eventually connected to form a glyph resembling a with an additional stroke at the bottom: ३. The Indian digits spread to the Caliphate in the 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Widescreen
Widescreen images are displayed within a set of aspect ratio (image), aspect ratios (relationship of image width to height) used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than 4:3 (1.33:1). For TV, the original screen ratio for broadcasts was in 4:3 (1.33:1). Largely between the 1990s and early 2000s, at varying paces in different countries, 16:9 (e.g. 1920×1080p 60p) widescreen displays came into increasingly common use by high-definition video, high definitions. With computer displays, aspect ratios other than 4:3 (e.g. 1920×1440) are also referred to as "widescreen". Widescreen computer displays were previously made in a 16:10 aspect ratio (e.g. 1920×1200), but nowadays they are 16:9 (e.g. 1920×1080, 2560×1440, 3840×2160). Film History Widescreen was first used for ''The Corbett-Fitzsimmons Fight'' (1897). This was not only the longest film that had been released to date at 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
