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Xerox 820
The Xerox 820 Information Processor is an 8-bit desktop computer sold by Xerox in the early 1980s. The computer runs under the CP/M operating system and uses floppy disk drives for mass storage. The microprocessor board is a licensed variant of the Big Board computer. 820 Xerox introduced the 820 in June 1981 for $2,995 with two -inch single-density disk drives with 81K of capacity per diskette, or $3,795 with two 8-inch drives with 241K capacity. To beat the IBM PC to market Xerox created little of the computer's design; it is based on the Ferguson Big Board computer kit and other off-the-shelf components, including a Zilog Z80 processor clocked at 2.5 MHz, and 64 KB of RAM. Xerox chose CP/M as its operating system because of the large software library—The 820 is compatible with all Big Board software—and sold a customized version of WordStar for $495, although by 1982 the company offered the standard version for the same price. By 1984, surplus 820 mainboards wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox 820
The Xerox 820 Information Processor is an 8-bit desktop computer sold by Xerox in the early 1980s. The computer runs under the CP/M operating system and uses floppy disk drives for mass storage. The microprocessor board is a licensed variant of the Big Board computer. 820 Xerox introduced the 820 in June 1981 for $2,995 with two -inch single-density disk drives with 81K of capacity per diskette, or $3,795 with two 8-inch drives with 241K capacity. To beat the IBM PC to market Xerox created little of the computer's design; it is based on the Ferguson Big Board computer kit and other off-the-shelf components, including a Zilog Z80 processor clocked at 2.5 MHz, and 64 KB of RAM. Xerox chose CP/M as its operating system because of the large software library—The 820 is compatible with all Big Board software—and sold a customized version of WordStar for $495, although by 1982 the company offered the standard version for the same price. By 1984, surplus 820 mainboards wer ... [...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 ( oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been 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 television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daisy Chain (information Technology)
In electrical and electronic engineering, a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring, similar to a garland of daisy flowers. Daisy chains may be used for power, analog signals, digital data, or a combination thereof. The term ''daisy chain'' may refer either to large scale devices connected in series, such as a series of power strips plugged into each other to form a single long line of strips, or to the wiring patterns embedded inside of devices. Other examples of devices which can be used to form daisy chains are those based on Universal Serial Bus (USB), FireWire, Thunderbolt and Ethernet cables. Signal transmission For analog signals, connections usually consist of a simple electrical bus and, especially in the case of a chain of many devices, may require the use of one or more repeaters or amplifiers within the chain to counteract attenuation (the natural loss of energy in such a system). Digital signals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaypro II
Kaypro Corporation was an American home and personal computer manufacturer based out of San Diego in the 1980s. The company was founded by Non-Linear Systems (NLS) to compete with the popular Osborne 1 portable microcomputer. Kaypro produced a line of rugged, "luggable" CP/M-based computers sold with an extensive software bundle which supplanted its competitors and quickly became one of the top-selling personal computer lines of the early 1980s. Kaypro was exceptionally loyal to its original customer base but slow to adapt to the changing computer market and the advent of IBM PC compatible technology. It faded from the mainstream before the end of the decade and was eventually forced into bankruptcy in 1992. History Kaypro began as Non-Linear Systems, a maker of electronic test equipment, founded in 1952 by Andrew Kay, the inventor of the digital voltmeter. In the 1970s, NLS was an early adopter of microprocessor technology, which enhanced the flexibility of products such as pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Array Logic
Programmable Array Logic (PAL) is a family of programmable logic device semiconductors used to implement logic functions in digital circuits introduced by Monolithic Memories, Inc. (MMI) in March 1978. Introductory advertisement on PAL (Programmable Array Logic). MMI obtained a registered trademark on the term PAL for use in "Programmable Semiconductor Logic Circuits". The trademark is currently held by Lattice Semiconductor.Monolithic Memories, Inc (MMI) filed for a work mark on the term "PAL" for use in "Programmable Semiconductor Logic Circuits" on April 13, 1978. A registered trademark was granted on April 29, 1980, registration number 1134025. MMI's first use of the term PAL in commerce was on February 21, 1978. The trademark is currently held by Lattice Semiconductor Corporation of Hillsboro, Oregon. Source: United States Patent and Trademark Office online database. PAL devices consisted of a small PROM (programmable read-only memory) core and additional output logic used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SCSI
Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interfaces. The SCSI standard defines command sets for specific peripheral device types; the presence of "unknown" as one of these types means that in theory it can be used as an interface to almost any device, but the standard is highly pragmatic and addressed toward commercial requirements. The initial Parallel SCSI was most commonly used for hard disk drives and tape drives, but it can connect a wide range of other devices, including scanners and CD drives, although not all controllers can handle all devices. The ancestral SCSI standard, X3.131-1986, generally referred to as SCSI-1, was published by the X3T9 technical committee of the American National Standards Institute (ANSI) in 1986. SCSI-2 was published in August 1990 as X3.T9.2/86-109 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital FD1771
The FD1771, sometimes WD1771, is the first in a line of floppy disk controllers produced by Western Digital. It uses single density FM encoding introduced in the IBM 3740. It is packaged in a 40-pin DIP."The FD1771 is a single-chip floppy disk formatter/controller that interfaces with most available disk drives and virtually all types of computers." The FD1771 was announced on July 19, 1976, and sold for $60 each in lots of 100. Later models in the series added support for MFM encoding and increasingly added onboard circuitry that formerly had to be implemented in external components. Originally packaged as 40-pin dual in-line package (DIP) format, later models moved to a 28-pin format that further lowered implementation costs. Derivatives The FD1771 was succeeded by many derivatives that were mostly software-compatible: *The FD1781 was designed for double density, but required external modulation and demodulation circuitry, so it could support MFM, M2FM, GCR or other dou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined by a formal language. Some languages are defined by a specification document (for example, the C programming language is specified by an ISO Standard) while other languages (such as Perl) have a dominant implementation that is treated as a reference. Some languages have both, with the basic language defined by a standard and extensions taken from the dominant implementation being common. Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages. Definitions There are many considerations when defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox BASIC-80
Microsoft BASIC is the foundation software product of the Microsoft company and evolved into a line of BASIC interpreters and compiler(s) adapted for many different microcomputers. It first appeared in 1975 as Altair BASIC, which was the first version of BASIC published by Microsoft as well as the first high-level programming language available for the Altair 8800 microcomputer. During the home computer craze during the late-1970s and early-1980s, BASIC was ported to and supplied with many home computer designs. Slight variations to add support for machine-specific functions, especially graphics, led to a profusion of related designs like Commodore BASIC and Atari Microsoft BASIC. As the early home computers gave way to newer designs like the IBM Personal Computer and Apple Macintosh, BASIC was no longer as widely used, although it retained a strong following. The release of Visual Basic reboosted its popularity and it remains in wide use on Microsoft Windows platforms in its mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washington, United States. Its best-known software products are the Windows line of operating systems, the Microsoft Office suite, and the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers. Microsoft ranked No. 21 in the 2020 Fortune 500 rankings of the largest United States corporations by total revenue; it was the world's largest software maker by revenue as of 2019. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Apple, and Meta. Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800. It rose to do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pin Header
A pin header (or simply header) is a form of electrical connector. A male pin header consists of one or more rows of metal pins molded into a plastic base, often apart, though available in many spacings. Male pin headers are cost-effective due to their simplicity. The female counterparts are sometimes known as female socket headers, though there are numerous naming variations of male and female connectors. Historically, headers have sometimes been called "Berg connectors", but headers are manufactured by many companies. Overview Normally pin headers are through-hole devices (THD / THT), but surface-mount devices (SMD / SMT) exist too. In the SMD case, the solder side of the pins are bent on a 90 degree angle so as to be soldered to pads on the PCB. On single row SMD headers the pins are bent alternating to one side or the other, on dual row SMD headers the pins are simply bent outwards. If pin headers are optional, the THD variant is often chosen for ease of manual assembl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerox 630
The Diablo 630 is a discontinued daisy wheel style computer printer sold by the Diablo Data Systems division of the Xerox Corporation beginning in 1980. The printer is capable of letter-quality printing; that is, its print quality is equivalent to the quality of an IBM Selectric typewriter or printer, the de facto quality standard of the time. Overview The printer is capable of this quality at a nominal speed of 30 characters per second (roughly twice the speed of the Selectric). Several technologies were introduced to enable this quality and speed: * The lightweight daisy wheel is rotated by a closed-loop servo and can be positioned rapidly and accurately. Because the wheel can turn in either direction, the next character is never more than 180° away from the previous character (and related characters are grouped together so the average "seek" is much less than 180°). * Like the "typeball" element on a Selectric, the daisy wheel can be easily changed, allowing for a wide va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
