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Acorn System 2
The Acorn Eurocard systems were a series of modular microcomputer systems based on rack-mounted Eurocards developed by Acorn Computers from 1979 to 1982, aimed primarily at industrial and laboratory use, but also home enthusiasts. The experience gained in developing this modular system strongly influenced the design of Acorn's first all-in-one home computer, the Acorn Atom, released in March 1980; and also much of the circuitry in its successor, the BBC Micro, first shown in late 1981. Acorn's final rack-based machine was the System 5, released in late 1982. The Eurocard business was then sold on to one of its principal resellers, Control Universal Ltd, which continued to develop various cards for industrial use based on the Acorn-standard bus during the 1980s, but ultimately went into receivership in 1989. Eurocards Placing the two Eurocards from the original Acorn Microcomputer onto a backplane made the system straightforward to expand in a modular way. The original I/O card, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Computers Ltd
The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns are long and on the fat side. Acorns take between 5 and 24 months (depending on the species) to mature; see the list of ''Quercus'' species for details of oak classification, in which acorn morphology and phenology are important factors. Etymology The word ''acorn'' (earlier ''akerne'', and ''acharn'') is related to the Gothic name ''akran'', which had the sense of "fruit of the unenclosed land". The word was applied to the most important forest produce, that of the oak. Chaucer spoke of "achornes of okes" in the 14th century. By degrees, popular etymology connected the word both with "corn" and "oak-horn", and the spelling changed accordingly. The current spelling (emerged 15c.-16c.), derives from associat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Atom Zx1
The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns are long and on the fat side. Acorns take between 5 and 24 months (depending on the species) to mature; see the list of ''Quercus'' species for details of oak classification, in which acorn morphology and phenology are important factors. Etymology The word ''acorn'' (earlier ''akerne'', and ''acharn'') is related to the Gothic name ''akran'', which had the sense of "fruit of the unenclosed land". The word was applied to the most important forest produce, that of the oak. Chaucer spoke of "achornes of okes" in the 14th century. By degrees, popular etymology connected the word both with "corn" and "oak-horn", and the spelling changed accordingly. The current spelling (emerged 15c.-16c.), derives from associat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Computers
Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the United Kingdom, UK, including the Acorn Electron and the Acorn Archimedes. Acorn's computer dominated the UK educational computer market during the 1980s. Though the company was acquired and largely dismantled in early 1999, with various activities being dispersed amongst new and established companies, its legacy includes the development of reduced instruction set computing (RISC) personal computers. One of its operating systems, , continues to be developed by RISC OS Open. Some activities established by Acorn lived on: technology developed by Arm (company), Arm, created by Acorn as a joint venture with Apple, Inc., Apple and VLSI Technology, VLSI in 1990, is dominant in the mobile phone and personal digital assistant (PDA) microprocessor market. Acorn is sometimes referred to as the "British Apple" and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel. Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floppy Disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks store digital data which can be read and written when the disk is inserted into a floppy disk drive (FDD) connected to or inside a computer or other device. The first floppy disks, invented and made by IBM, had a disk diameter of . Subsequently, the 5¼-inch and then the 3½-inch became a ubiquitous form of data storage and transfer into the first years of the 21st century. 3½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for 5¼-inch, 8-inch, and other-size floppy disks are rare to non-existent. Some individuals and organizations continue to use older equipment to read or transfer data from floppy disks. Floppy disk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BASIC
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963. They wanted to enable students in non-scientific fields to use computers. At the time, nearly all computers required writing custom software, which only scientists and mathematicians tended to learn. In addition to the program language, Kemeny and Kurtz developed the Dartmouth Time Sharing System (DTSS), which allowed multiple users to edit and run BASIC programs simultaneously on remote terminals. This general model became very popular on minicomputer systems like the PDP-11 and Data General Nova in the late 1960s and early 1970s. Hewlett-Packard produced an entire computer line for this method of operation, introducing the HP2000 series in the late 1960s and continuing sales into the 1980s. Many early video games trace their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAA5050
The Mullard SAA5050 was a character generator chip for implementing the Teletext character set. The SAA5050 was used in teletext-equipped television sets, viewdata terminals, and microcomputers, most notably on computers like the Philips P2000 (1980), Acorn System 2 (1980), BBC Micro (1982), Malzak and the Poly-1. This chip was also manufactured by Mullard for Philips. Operation The chip generated appropriate video output for a 7-bit input character code representing the current character on the text line, while keeping track of the effect of any of the various control characters defined by the teletext standard that had previously occurred in that text line, which could be used to change the foreground and background colour, switch to or from the alternate block graphics character set, or various other effects. Full-screen resolution generated by the SAA5050 was 480×500 pixels, corresponding to 40×25 characters. Each character position therefore corresponded to a 12×20 pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MC6845
The Motorola 6845, or MC6845, is a display controller that was widely used in 8-bit computers during the 1980s. Originally intended for designs based on the Motorola 6800 CPU and given a related part number, it was more widely used alongside various other processors, and was most commonly found in machines based on the Zilog Z80 and MOS 6502. The 6845 is not an entire display solution on its own; the chip's main function is to properly time access to the display memory, and to calculate the memory address of the next portion to be drawn. Other circuitry in the machine then uses the address provided by the 6845 to fetch the pattern and then draw it. The implementation of that hardware is entirely up to the designer and varied widely among machines. The 6845 is intended for character displays, but could also be used for pixel-based graphics, with some clever programming. Among its better-known uses is the BBC Micro, Amstrad CPC, and Videx VideoTerm display cards for the Apple II ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets. Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen. The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format, typically displayed on a television or a dumb terminal, but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel. Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Printed Circuit Boards
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component's terminals, generally by means of soldering, to both electrically connect and mechanically fasten them to it. Another manufacturing process adds vias: plated-through holes that allow interconnections between layers. Printed circuit boards are used in nearly all electronic products. Alternatives to PCBs include wire wrap a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn System 1
The Acorn System 1, initially called the Acorn Microcomputer (Micro-Computer), was an early 8-bit microcomputer for hobbyists, based on the MOS 6502 CPU, and produced by British company Acorn Computers from 1979. The main parts of the system were designed by then-Cambridge-undergraduate student Sophie Wilson, with a cassette interface designed by Steve Furber.http://www.stairwaytohell.com/articles/SG-SophieWilson.html Sophie Wilson - 2007 Interview with Stuart Goodwin It was Acorn's first product, and was based on an automated cow feeder. It was a small machine built on two Eurocard-standard circuit boards and it could be purchased ready-built or in kit form. *one card (shown right) with the I/O part of the computer: a LED seven segment display, a 25-key keypad ( hex+function keys), and a cassette CUTS interface (the circuitry to the left of the keypad) *the second card (the computer board - see below), which included the CPU, RAM/ROM memory, and support chips *the two boar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motorola 6809
The Motorola 6809 ("''sixty-eight-oh-nine''") is an 8-bit microprocessor with some 16-bit features. It was designed by Motorola's Terry Ritter and Joel Boney and introduced in 1978. Although source compatible with the earlier Motorola 6800, the 6809 offered significant improvements over it and 8-bit contemporaries like the MOS Technology 6502, including a hardware multiplication instruction, 16-bit arithmetic, system and user stack registers allowing re-entrant code, improved interrupts, position-independent code and an orthogonal instruction set architecture with a comprehensive set of addressing modes. Among the most powerful 8-bit processors of its era, it was also much more expensive. In 1980 a 6809 in single-unit quantities was compared to for a Zilog Z80 and for a 6502. It was launched when a new generation of 16-bit processors were coming to market, like the Intel 8086, and 32-bit designs were on the horizon, including Motorola's own 68000. It was not feature competitiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
