APL is a programming language developed in the 1960s by Kenneth E. Iverson. Its central datatype is the multidimensional array. It uses a large range of special graphic symbols to represent most functions and operators, leading to very concise code. It has been an important influence on the development of concept modeling, spreadsheets, functional programming, and computer math packages. It has also inspired several other programming languages.
Mainframe computers or mainframes are computers used primarily by large organizations for critical applications; bulk data processing, such as census, industry and consumer statistics, enterprise resource planning; and transaction processing. They are larger and have more processing power than some other classes of computers: minicomputers, servers, workstations, and personal computers.
Scroll lock is a lock key on most IBM-compatible computer keyboards.
In computing, booting is starting up a computer or computer appliance until it can be used. It can be initiated by hardware such as a button press or by software command. After the power is switched on, the computer is relatively dumb and can read only part of its storage called read-only memory (ROM). There, a small program is stored called firmware. It does power-on self-tests and, most importantly, allows accessing other types of memory like a hard disk and main memory. The firmware loads bigger programs into the computer's main memory and runs it. In general purpose computers, but additionally in smartphones and tablets, optionally a boot manager is run. The boot manager lets a user choose which operating system to run and set more complex parameters for it. The firmware or the boot manager then loads the boot loader into the memory and runs it. This piece of software is able to place an operating system kernel like Windows or Linux into the computer's main memory and run it. Afterwards, the kernel runs so-called user space software – well known is the graphical user interface (GUI), which lets the user log in to the computer or run some other applications. The whole process may take seconds to tenths of seconds on modern day general purpose computers.
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display.
A terminal emulator, terminal application, or term, is a program that emulates a video terminal within some other display architecture. Though typically synonymous with a shell or text terminal, the term terminal covers all remote terminals, including graphical interfaces. A terminal emulator inside a graphical user interface is often called a terminal window.
The IBM 1620 was announced by IBM on October 21, 1959, and marketed as an inexpensive "scientific computer". After a total production of about two thousand machines, it was withdrawn on November 19, 1970. Modified versions of the 1620 were used as the CPU of the IBM 1710 and IBM 1720 Industrial Process Control Systems
Typesetting is the composition of text by means of arranging physical types or the digital equivalents. Stored letters and other symbols are retrieved and ordered according to a language's orthography for visual display. Typesetting requires one or more fonts. One significant effect of typesetting was that authorship of works could be spotted more easily, making it difficult for copiers who have not gained permission.
In computing, a Control key is a modifier key which, when pressed in conjunction with another key, performs a special operation ; similar to the Shift key, the Control key rarely performs any function when pressed by itself. The Control key is located on or near the bottom left side of most keyboards, with many featuring an additional one at the bottom right.
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying or printing data from, a computer or a computing system. The teletype was an example of an early day hardcopy terminal, and predated the use of a computer screen by decades.
Kenneth Eugene Iverson was a Canadian computer scientist noted for the development of the programming language APL. He was honored with the Turing Award in 1979 "for his pioneering effort in programming languages and mathematical notation resulting in what the computing field now knows as APL; for his contributions to the implementation of interactive systems, to educational uses of APL, and to programming language theory and practice".
The game port, originally introduced on the Game Control Adapter, is a device port that was found on IBM PC compatible and other computer systems throughout the 1980s and 1990s. It was the traditional connector for joystick input, and occasionally MIDI devices, until replaced by USB in the 21st century.
In electronics and technology, a reset button is a button that can reset a device. On video game consoles, the reset button restarts the game, losing the player's unsaved progress. On personal computers, the reset button clears the memory and reboots the machine forcibly. Reset buttons are found on circuit breakers to reset the circuit. This button can cause data corruption so this button often doesn't exist on many machines. Usually, in computers and other electronic devices, it is present as a small button, possibly recessed into the case or only accessible by a pin or similar thin object, to prevent it being pressed accidentally.
Caps Lock is a button on a computer keyboard that causes all letters of Latin-based scripts to be generated in capitals. It is a toggle key: each press reverses its action. Some keyboards also implement a light, so as to give visual feedback about whether it is on or off. Exactly what Caps Lock does depends on the keyboard hardware, the operating system, the device driver, and the keyboard layout. Usually, the effect is limited to letter keys; letters of Latin-based scripts are capitalised, while letters of other scripts and non-letter characters are generated normally.
Common User Access (CUA) is a standard for user interfaces to operating systems and computer programs. It was developed by IBM and first published in 1987 as part of their Systems Application Architecture. Used originally in the MVS/ESA, VM/CMS, OS/400, OS/2 and Microsoft Windows operating systems, parts of the CUA standard are now implemented in programs for other operating systems, including variants of Unix. It is also used by Java AWT and Swing.
On personal computers, the turbo button is a button which provides two run states for the computer: normal speed or an enhanced "turbo" speed. It was relatively common on personal computers using the Intel 80286, Intel 80386 and Intel 80486 processors, from the mid 1980s to mid 1990s.
The Option key is a modifier key (ALT) present on Apple keyboards. It is located between the Control key and Command key on a typical Mac keyboard. There are two option keys on modern Mac desktop and notebook keyboards, one on each side of the space bar.
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.
The Microwriter is a hand-held portable word-processor with a chording keyboard. First demonstrated in 1978, it was invented by UK-based, US-born film director Cy Endfield and his partner Chris Rainey and was marketed in the early 1980s by Microwriter Ltd, of Mitcham, Surrey, UK. By using a mnemonic alphabet, it was claimed to allow note-taking of up to 8,000 characters at an input rate averaging 1.5 times that of handwriting.
In computing, a computer keyboard is a typewriter-style device which uses an arrangement of buttons or keys to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input method for computers.
