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Decsystem-20
The DECSYSTEM-20 was a family of 36-bit Digital Equipment Corporation PDP-10 mainframe computers running the TOPS-20 operating system and was introduced in 1977. PDP-10 computers running the TOPS-10 operating system were labeled ''DECsystem-10'' as a way of differentiating them from the PDP-11. Later on, those systems running TOPS-20 (on the KL10 PDP-10 processors) were labeled ''DECSYSTEM-20'' (the block capitals being the result of a lawsuit brought against DEC by Singer, which made its own System Ten model, occasionally referenced in reporting as the "System 10"). The DECSYSTEM-20 was sometimes called PDP-20, although this designation was never used by DEC. Models The following models were produced: *DECSYSTEM-2020: KS10 bit-slice processor with up to 512 kilowords of solid state RAM (The ADP OnSite version of the DECSYSTEM-2020 supported 1 MW of RAM) *DECSYSTEM-2040: KL10 ECL processor with up to 1024 kilowords of magnetic core RAM *DECSYSTEM-2050: KL10 ECL proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDP-10
Digital Equipment Corporation (DEC)'s PDP-10, later marketed as the DECsystem-10, is a mainframe computer family manufactured beginning in 1966 and discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especially as the TOPS-10 operating system became widely used. The PDP-10's architecture is almost identical to that of DEC's earlier PDP-6, sharing the same 36-bit Word (computer architecture), word length and slightly extending the instruction set. The main difference was a greatly improved hardware implementation. Some aspects of the instruction set are unusual, most notably the ''byte'' instructions, which operate on bit fields of any size from 1 to 36 bits inclusive, according to the general definition of a byte as ''a contiguous sequence of a fixed number of bits''. The PDP-10 was found in many university computing facilities and research labs during the 1970s, the most notable being Harvard University's Aiken Computation Laboratory, Mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmed Data Processor
Programmed Data Processor (PDP), referred to by some customers, media and authors as "Programmable Data Processor," is a term used by the Digital Equipment Corporation from 1957 to 1990 for several lines of minicomputers. The name "PDP" intentionally avoids the use of the term "computer". At the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines. The venture capitalists behind Digital (especially Georges Doriot) would not support Digital's attempting to build a "computer" and the term "minicomputer" had not yet been coined. So instead, Digital used their existing line of logic modules to build a ''Programmed Data Processor'' and aimed it at a market that could not afford the larger computers. The various PDP machines can generally be grouped into families based on word length. Series Members of the PDP series include: ;PDP-1: The original PDP, an 18-bit computing, 18-bit four-19-inch rack, rack machine used in early tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOPS-20
The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP-10 and the DECSYSTEM-20). TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman (BBN) and shipped as a product by DEC starting in 1976. TOPS-20 is almost entirely unrelated to the similarly named TOPS-10, but it was shipped with the PA1050 TOPS-10 Monitor Calls emulation facility which allowed most, but not all, TOPS-10 executables to run unchanged. As a matter of policy, DEC did not update PA1050 to support later TOPS-10 additions except where required by DEC software. TOPS-20 competed with TOPS-10, ITS and WAITS—all of which were notable time-sharing systems for the PDP-10 during this timeframe. TOPS-20 is informally known as TWENEX. TENEX TOPS-20 was based upon the TENEX operating system, which had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living Computer Museum
Living Computers: Museum + Labs (LCM+L) was a computer and technology museum located in the SoDo neighborhood of Seattle, Washington. LCM+L showcased vintage computers which provided interactive sessions, either through time-sharing operating systems or single-user interfaces. This gave users a chance to actually use the computers online or in-person in the museum. An expansion had added direct touch experiences with contemporary technologies such as self-driving cars, the internet of things, big data, and robotics. LCM+L had also hosted a wide range of educational programs and events in their state-of-the art classroom and lab spaces. According to an archived version of LCM+L's website, their goal was "to breathe life back into our machines so the public can experience what it was like to see them, hear them, and interact with them. We make our systems accessible by allowing people to come and interact with them, and by making them available over the Internet." The museum cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DECsystem 2020 Logo
DECsystem was a line of server computers from Digital Equipment Corporation. They were based on MIPS architecture processors and ran DEC's version of the UNIX operating system, called ULTRIX. They ranged in size from workstation-style desktop enclosures to large pedestal cabinets. The DECSYSTEM name was used for later models of the PDP-10, namely the DECSYSTEM-10 and DECSYSTEM-20 series. Models DECsystem 3100 Identical to the DECstation 3100, but intended as a multiuser system. It was announced in early May 1989 at the UniForum exhibition in San Francisco. It was shipped in June 1989. Code name PMAX. DECsystem 5000 Series Rebranded Personal DECstation 5000 Series without graphics. Code name MAXINE. DECsystem 5000 Model 100 Series Rebranded DECstation 5000 Model 100 Series without graphics. Codename 3MIN. DECsystem 5000 Model 200 Series Rebranded DECstation 5000 Model 200 Series without graphics. Code name 3MAX. (5000/260 3MAX+). DECsystem 5100 A desktop uniproc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until he was forced to resign in 1992, after the company had gone into precipitous decline. The company produced many different product lines over its history. It is best known for the work in the minicomputer market starting in the early 1960s. The company produced a series of machines known as the Programmed Data Processor, PDP line, with the PDP-8 and PDP-11 being among the most successful minis in history. Their success was only surpassed by another DEC product, the late-1970s VAX "supermini" systems that were designed to replace the PDP-11. Although a number of competitors had successfully competed with Digital through the 1970s, the VAX cemented the company's place as a leading vendor in the computer space. As microcomputers improved in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
36-bit
36-bit computers were popular in the early mainframe computer era from the 1950s through the early 1970s. Starting in the 1960s, but especially the 1970s, the introduction of 7-bit ASCII and 8-bit EBCDIC led to the move to machines using 8-bit bytes, with word sizes that were multiples of 8, notably the 32-bit IBM System/360 mainframe and Digital Equipment VAX and Data General MV series superminicomputers. By the mid-1970s the conversion was largely complete, and microprocessors quickly moved from 8-bit to 16-bit to 32-bit over a period of a decade. The number of 36-bit machines rapidly fell during this period, offered largely for backward compatibility purposes running legacy programs. History Prior to the introduction of computers, the state of the art in precision scientific and engineering calculation was the ten-digit, electrically powered, mechanical calculator, such as those manufactured by Friden, Marchant and Monroe. These calculators had a column of keys for eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Allen
Paul Gardner Allen (January 21, 1953 – October 15, 2018) was an American businessman, computer programmer, and investor. He co-founded Microsoft, Microsoft Corporation with his childhood friend Bill Gates in 1975, which was followed by the microcomputer revolution of the 1970s and 1980s. Allen was ranked as the The World's Billionaires, 44th-wealthiest person in the world by ''Forbes'' with an estimated net worth of $20.3 billion at the time of his death in October 2018. Allen quit from day-to-day work at Microsoft in early 1983 after a Hodgkin lymphoma diagnosis, remaining on its board as vice-chairman. He and his sister, Jody Allen, founded Vulcan Inc. in 1986, a privately held company that managed his business and philanthropic efforts. At the time of his death, he had a multi-billion dollar investment portfolio, including technology and media companies, scientific research, real estate holdings, private space flight ventures, and stakes in other sectors. He owned the Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emitter-coupled Logic
In electronics, emitter-coupled logic (ECL) is a high-speed integrated circuit bipolar transistor logic family. ECL uses a bipolar junction transistor (BJT) differential amplifier with single-ended input and limited emitter current to avoid the saturated (fully on) region of operation and the resulting slow turn-off behavior. As the current is steered between two legs of an emitter-coupled pair, ECL is sometimes called ''current-steering logic'' (CSL), ''current-mode logic'' (CML) or ''current-switch emitter-follower'' (CSEF) logic. In ECL, the transistors are never in saturation, the input and output voltages have a small swing (0.8 V), the input impedance is high and the output impedance is low. As a result, the transistors change states quickly, gate delays are low, and the fanout capability is high. In addition, the essentially constant current draw of the differential amplifiers minimizes delays and glitches due to supply-line inductance and capacitance, and the compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARPANET
The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first computer networks to implement the TCP/IP protocol suite. Both technologies became the technical foundation of the Internet. The ARPANET was established by the Advanced Research Projects Agency (now DARPA) of the United States Department of Defense. Building on the ideas of J. C. R. Licklider, Robert Taylor (computer scientist), Bob Taylor initiated the ARPANET project in 1966 to enable resource sharing between remote computers. Taylor appointed Lawrence Roberts (scientist), Larry Roberts as program manager. Roberts made the key decisions about the request for proposal to build the network. He incorporated Donald Davies' concepts and designs for packet switching, and sought input from Paul Baran on dynamic routing. In 1969, ARPA awarded the contract to build the Interface Message Processors (IMPs) for the network to Bolt Berane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email Spam
Email spam, also referred to as junk email, spam mail, or simply spam, refers to unsolicited messages sent in bulk via email. The term originates from a Spam (Monty Python), Monty Python sketch, where the name of a canned meat product, "Spam (food), Spam," is used repetitively, mirroring the intrusive nature of unwanted emails. Since the early 1990s, spam has grown significantly, with estimates suggesting that by 2014, it comprised around 90% of all global email traffic. Spam is primarily a financial burden for the recipient, who may be required to manage, filter, or delete these unwanted messages. Since the expense of spam is mostly borne by the recipient, it is effectively a form of "postage due" advertising, where the recipient bears the cost of unsolicited messages. This cost imposed on recipients, without compensation from the sender, makes spam an example of a "negative externality" (a side effect of an activity that affects others who are not involved in the decision). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
