|
TV Typewriter
The TV Typewriter is a video terminal that could display two pages of 16 lines of 32 upper case characters on a standard television set. The design, by Don Lancaster, appeared on the cover of ''Radio-Electronics'' magazine in September 1973. The magazine included a 6-page description of the design but readers could send off for a 16-page package of construction details. ''Radio-Electronics'' sold thousands of copies for $2.00 each. The TV Typewriter is considered a milestone in the home computer revolution along with the Mark-8 and Altair 8800 computers. "A giant step toward the realization of the personal-computer dream happened in 1973, when Radio Electronics published an article by Don Lancaster that described a 'TV Typewriter'.""One influential project was the TV-Typewriter, designed by Don Lancaster and published in ''Radio-Electronics'' in September 1973." Sometimes the term was used generically for any interactive computer display on a screen; until CRT displays were develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signetics
Signetics Corporation was an American electronics manufacturer specifically established to make integrated circuits. Founded in 1961, they went on to develop a number of early microprocessors and support chips, as well as the widely used 555 timer IC, 555 timer chip. The company was bought by Philips in 1975 and incorporated in NXP Semiconductors, Philips Semiconductors (now NXP). History Signetics was started in 1961, by a group of engineers (David Allison, David James, Lionel Kattner, and Mark Weissenstern) who had left Fairchild Semiconductor. At the time, Fairchild was concentrating on its discrete component business (mostly transistors), and its management felt that by making integrated circuits (ICs) it would lose its customers. Signetics founders believed that ICs were the future of electronics (much like another contemporary Fairchild spinoff, Amelco) and wished to commercialize them. The name of the new company was coined from Signal Network Electronics. The venture was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Electronics Cover Sept 1973
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shift Register
A shift register is a type of digital circuit using a cascade of flip-flop (electronics), flip-flops where the output of one flip-flop is connected to the input of the next. They share a single clock signal, which causes the data stored in the system to shift from one location to the next. By connecting the last flip-flop back to the first, the data can cycle within the shifters for extended periods, and in this configuration they were used as computer memory, displacing delay-line memory systems in the late 1960s and early 1970s. In most cases, several parallel shift registers would be used to build a larger memory pool known as a "bit array". Data was stored into the array and read back out in parallel, often as a computer word, while each bit was stored serially in the shift registers. There is an inherent trade-off in the design of bit arrays; putting more flip-flops in a row allows a single shifter to store more bits, but requires more clock cycles to push the data through all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CT1024 Monitor
CT1 stands for ''Cordless telephone generation 1'' and is an analog cordless telephone standard that was standardized by the European Conference of Postal and Telecommunications Administrations (CEPT) in 1984 and deployed in eleven European countries. The initial set of frequencies provided for a set 40 duplex channels using 25 kHz separation, with the phones transmitting in the 914-915 MHz band and the base stations in the 959-960 MHz band. These frequencies overlap with those used by channels 120-124 on GSM cellular phones and thus these original frequencies have been withdrawn from use for cordless phones in the countries that originally authorized them. CT1+ provided in 1987 for a set of 80 additional channels using the same technical standard with 885–887 MHz used by the phones and 930–932 MHz used by the base stations. While not part of the original GSM-900 band, the frequencies do overlap with the extended GSM-900 band. Thus between the adve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistor–transistor Logic
Resistor–transistor logic (RTL), sometimes also known as transistor–resistor logic (TRL), is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit; it was succeeded by diode–transistor logic (DTL) and transistor–transistor logic (TTL). RTL circuits were first constructed with discrete components, but in 1961 it became the first digital logic family to be produced as a monolithic integrated circuit. RTL integrated circuits were used in the Apollo Guidance Computer, whose design began in 1961 and which first flew in 1966. Implementation RTL inverter A bipolar Transistor#Transistor as a switch, transistor switch is the simplest RTL gate (Inverter (logic gate), inverter or NOT gate) implementing logical negation. It consists of a Common emitter, common-emitter stage with a base resistor connected between the base and the input v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer History Museum
The Computer History Museum (CHM) is a computer museum in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the Information Age, and explores the Digital Revolution, computing revolution and its impact on society. History The museum's origins date to 1968 when Gordon Bell began a quest for a historical collection and, at that same time, others were looking to preserve the Whirlwind (computer), Whirlwind computer. The resulting ''Museum Project'' had its first exhibit in 1975, located in a converted coat closet in a Digital Equipment Corporation, DEC lobby. In 1978, the museum, now ''The Digital Computer Museum'' (TDCM), moved to a larger DEC lobby in Marlborough, Massachusetts and opened to the public in September 1979. Maurice Wilkes presented the first lecture at TDCM in 1979 – the presentation of such lectures has continued to the present time. TDCM incorporated as ''The Computer Museum, Boston, The Computer Museum'' (TCM) in 1982. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EBCDIC
Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight- bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six-bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s. It is supported by various non-IBM platforms, such as Fujitsu-Siemens' BS2000/OSD, OS-IV, MSP, and MSP-EX, the SDS Sigma series, Unisys VS/9, Unisys MCP and ICL VME. History EBCDIC was devised in 1963 and 1964 by IBM and was announced with the release of the IBM System/360 line of mainframe computers. It is an eight-bit character encoding, developed separately from the seven-bit ASCII encoding scheme. It was created to extend the existing Binary-Coded Decimal (BCD) Interchange Code, or BCDIC, which itself was devised as an efficient means of encoding the two ''zone'' and ''number'' punches on punched cards into six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baudot Code
The Baudot code () is an early character encoding for telegraphy invented by Émile Baudot in the 1870s. It was the predecessor to the International Telegraph Alphabet No. 2 (ITA2), the most common teleprinter code in use before ASCII. Each character in the alphabet is represented by a series of five bits, sent over a communication channel such as a telegraph wire or a radio signal by asynchronous serial communication. The symbol rate measurement is known as baud, and is derived from the same name. History Baudot code (ITA1) In the below table, Columns I, II, III, IV, and V show the code; the Let. and Fig. columns show the letters and numbers for the Continental and UK versions; and the sort keys present the table in the order: alphabetical, Gray and UK Baudot developed his first multiplexed telegraph in 1872 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII. ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits ''0'' to ''9'', lowercase letters ''a'' to ''z'', uppercase letters ''A'' to ''Z'', and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SWTPC Keyboard
Southwest Technical Products Corporation, or SWTPC, was an American producer of electronic kits, and later complete computer systems. It was incorporated in 1967 in San Antonio, Texas, succeeding the Daniel E. Meyer Company. In 1990, SWTPC became Point Systems, before ceasing a few years later. History In the 1960s, many hobbyist electronics magazines such as ''Popular Electronics'' and ''Radio-Electronics'' published construction articles, for many of which the author would arrange for a company to provide a kit of parts to build the project. Daniel Meyer published several popular projects and successfully sold parts kits. He soon started selling kits for other authors such as Don Lancaster and Louis Garner. Between 1967 and 1971, SWTPC sold kits for over 50 ''Popular Electronics'' articles. Most of these kits were intended for audio use, such as hi-fi, utility amplifiers, and test equipment such as a function generator based on the Intersil ICL8038. Many of these early ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Cassette
The Compact Cassette, also commonly called a cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens and his team at the Dutch company Philips, the Compact Cassette was released in August 1963. Compact Cassettes come in two forms, either containing content as a prerecorded cassette (''Musicassette''), or as a fully recordable "blank" cassette. Both forms have two sides and are reversible by the user. Although other tape cassette formats have also existed—for example the Microcassette—the generic term ''cassette tape'' is normally used to refer to the Compact Cassette because of its ubiquity. From 1983 to 1991 the cassette tape was the most popular audio format for new music sales in the United States. Compact Cassettes contain two miniature spools, between which the magnetically coated, polyester-type plastic film (magnetic tape) is passed and wound—essentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
