|
Digital Ethernet Local Network Interconnect
DECnet is a suite of network protocols created by Digital Equipment Corporation. Originally released in 1975 in order to connect two PDP-11 minicomputers, it evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s. Initially built with three layers, it later (1982) evolved into a seven-layer OSI-compliant networking protocol. DECnet was built right into the DEC flagship operating system OpenVMS since its inception. Later Digital ported it to Ultrix, OSF/1 (later Tru64) as well as Apple Macintosh and IBM PC running variants of DOS, OS/2 and Microsoft Windows under the name PATHWORKS, allowing these systems to connect to DECnet networks of VAX machines as terminal nodes. While the DECnet protocols were designed entirely by Digital Equipment Corporation, DECnet Phase II (and later) were open standards with published specifications, and several implementations were developed outside DEC, including ones for Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols are to communicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Standard
An open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to their inherently open nature. There is no single definition, and interpretations vary with usage. Examples of open standards include the GSM, 4G, and 5G standards that allow most modern mobile phones to work world-wide. Definitions The terms ''open'' and ''standard'' have a wide range of meanings associated with their usage. There are a number of definitions of open standards which emphasize different aspects of openness, including the openness of the resulting specification, the openness of the drafting process, and the ownership of rights in the standard. The term "standard" is sometimes restricted to technologies approved by formalized committees that are open to participation by all interested parties and operate on a consensus basis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RSTS/E
RSTS () is a multi-user time-sharing operating system developed by Digital Equipment Corporation (DEC, now part of Hewlett-Packard) for the PDP-11 series of 16-bit minicomputers. The first version of RSTS (RSTS-11, #Versions, Version 1) was implemented in 1970 by DEC Software engineering, software engineers that developed the TSS-8 time-sharing operating system for the PDP-8. The last version of RSTS (RSTS/E, #Versions, Version 10.1) was released in September 1992. RSTS-11 and RSTS/E are usually referred to just as "RSTS" and this article will generally use the shorter form. RSTS-11 supports the BASIC programming language, an extended version called BASIC-PLUS, developed under contract by ''Evans Griffiths & Hart'' of Boston. Starting with RSTS/E version 5B, DEC added support for additional programming languages by emulating the execution environment of the RT-11 and RSX-11 operating systems. Acronyms and abbreviations *BTSS (Basic Time Sharing System – never marketed) – The f ... [...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] |
DDCMP
Digital Data Communications Message Protocol (DDCMP) is a byte-oriented communications protocol devised by Digital Equipment Corporation in 1974 to allow communication over point-to-point network links for the company's DECnet Phase I network protocol suite. The protocol uses full or half duplex synchronous and asynchronous Asynchrony is any dynamic far from synchronization. If and as parts of an asynchronous system become more synchronized, those parts or even the whole system can be said to be in sync. Asynchrony or asynchronous may refer to: Electronics and com ... links and allowed errors introduced in transmission to be detected and corrected. It was retained and extended for later versions of the DECnet protocol suite. DDCMP has been described as the "most popular and pervasive of the commercial byte-count data link protocols". See also * DEX References Overview of the protocolProtocol specification(courtesy of DEC) ;Notes Network protocols {{compu-networ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDP-8
The PDP-8 is a family of 12-bit minicomputers that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units sold during the model's lifetime. Its basic design follows the pioneering LINC but has a smaller instruction set, which is an expanded version of the PDP-5 instruction set. Similar machines from DEC are the PDP-12 which is a modernized version of the PDP-8 and LINC concepts, and the PDP-14 industrial controller system. Overview The earliest PDP-8 model, informally known as a "Straight-8", was introduced on 22 March 1965 priced at $18,500 (). It uses diode–transistor logic packaged on flip chip cards in a machine about the size of a small household refrigerator. It was the first computer to be sold for under $20,000, making it the best-selling computer in history at that time. The Straight-8 was supplanted in 1966 by the PDP-8/S, which was available in desktop and rack-mount models. Using a on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RSX-11
RSX-11 is a discontinued family of multi-user real-time operating systems for PDP-11 computers created by Digital Equipment Corporation. In widespread use through the late 1970s and early 1980s, RSX-11 was influential in the development of later operating systems such as OpenVMS, VMS and Windows NT. As the original ''Real-Time System Executive'' name suggests, RSX was designed (and commonly used) for real time use, with process control a major use. It was also popular for program development and general computing. History Name and origins RSX-11 began as a port to the PDP-11 architecture of the earlier RSX-15 operating system for the PDP-15 minicomputer, first released in 1971. The main architect for RSX-15 (later renamed XVM/RSX) was Dennis “Dan” Brevik. Commenting on the ''RSX'' acronym, Brevik says: RSX-11D and IAS The porting effort first produced small paper tape based real-time executives (RSX-11A, RSX-11C) which later gained limited support for disks (RSX-11B). RSX ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systems Network Architecture
Systems Network Architecture (SNA) is IBM's proprietary computer network, networking architecture, created in 1974. It is a complete protocol stack for interconnecting computers and their resources. SNA describes formats and protocols but, in itself, is not a piece of software. The implementation of SNA takes the form of various communications packages, most notably Virtual Telecommunications Access Method (VTAM), the mainframe computer, mainframe software package for SNA communications. History SNA was made public as part of IBM's "Advanced Function for Communications" announcement in September, 1974, which included the implementation of the SNA/SDLC (Synchronous Data Link Control) protocols on new communications products: *IBM 3767 communication terminal (printer) *IBM 3770 data communication system They were supported by IBM 3705 Communications Controller, IBM 3704/3705 communication controllers and their IBM Network Control Program, Network Control Program (NCP), and by Syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Area Transport
Local Area Transport (LAT) is a non-routable (data link layer) networking technology developed by Digital Equipment Corporation to provide connection between the DECserver terminal servers and Digital's VAX and Alpha and MIPS host computers via Ethernet, giving communication between those hosts and serial devices such as video terminals and printers. The protocol itself was designed in such a manner as to maximize packet efficiency over Ethernet by bundling multiple characters from multiple ports into a single packet for Ethernet transport. One ''LAT'' strength was efficiently handling time-sensitive data transmission. Over time, other host implementations of the LAT protocol appeared allowing communications to a wide range of Unix and other non-Digital operating systems using the LAT protocol. History In 1984, the first implementation of the LAT protocol connected a terminal server to a VMS VAX-Cluster in Spit Brook Road, Nashua, NH. By "virtualizing" the terminal port at the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Packet Sniffer
A packet analyzer (also packet sniffer or network analyzer) is a computer program or computer hardware such as a packet capture appliance that can Traffic analysis, analyze and Logging (computing), log traffic that passes over a computer network or part of a network. Packet capture is the process of intercepting and logging traffic. As data streams flow across the network, the analyzer captures each Network packet, packet and, if needed, decodes the packet's raw data, showing the values of various fields in the packet, and analyzes its content according to the appropriate Request for Comments, RFC or other specifications. A packet analyzer used for intercepting traffic on wireless networks is known as a wireless analyzer - those designed specifically for Wi-Fi networks are Wi-Fi analyzers. While a packet analyzer can also be referred to as a Network analyzer (other), network analyzer or protocol analyzer these terms can also have other meanings. Protocol analyzer can t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocol Stack
The protocol stack or network stack is an implementation of a computer networking protocol suite or protocol family. Some of these terms are used interchangeably but strictly speaking, the ''suite'' is the definition of the communication protocols, and the ''stack'' is the software implementation of them. Individual protocols within a suite are often designed with a single purpose in mind. This modularization simplifies design and evaluation. Because each protocol module usually communicates with two others, they are commonly imagined as layers in a stack of protocols. The lowest protocol always deals with low-level interaction with the communications hardware. Each higher layer adds additional capabilities. User applications usually deal only with the topmost layers. General protocol suite description T ~ ~ ~ T ____ Imagine three computers: ''A'', ''B'', and ''C''. ''A'' and ''B'' both have radio equipment and can communicate via the airwaves using a suitable net ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
