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Binary Synchronous
Binary Synchronous Communication (BSC or Bisync) is an IBM character-oriented, half-duplex link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous transmit-receive (STR) protocol used with second generation computers. The intent was that common link management rules could be used with three different character encodings for messages. Six-bit Transcode looked backward to older systems; USASCII with 128 characters and EBCDIC with 256 characters looked forward. Transcode disappeared very quickly but the EBCDIC and USASCII dialects of Bisync continued in use. At one time Bisync was the most widely used communications protocol and is still in limited use in 2013. Framing Bisync differs from protocols that succeeded it in the complexity of message framing. Later protocols use a single framing scheme for all messages sent by the protocol. HDLC, Digital Data Communications Message Protocol (DDCMP), Point-to-Point Protocol (PPP), etc. ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link Protocol
In computer networking, the link layer is the lowest layer in the Internet protocol suite, the networking architecture of the Internet. The link layer is the group of methods and communications protocols confined to the link that a host is physically connected to. The link is the physical and logical network component used to interconnect hosts or nodes in the network and a link protocol is a suite of methods and standards that operate only between adjacent network nodes of a network segment. Despite the different semantics of layering between the Internet protocol suite and OSI model, the link layer is sometimes described as a combination of the OSI's data link layer (layer 2) and physical layer (layer 1). The link layer is described in and . RFC 1122 considers local area network protocols such as Ethernet and other IEEE 802 networks (e.g. Wi-Fi), and framing protocols such as Point-to-Point Protocol (PPP) to belong to the link layer. Definition in standards and textbooks L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative-acknowledge Character
In data networking, telecommunications, and computer buses, an acknowledgement (ACK) is a signal that is passed between communicating processes, computers, or devices to signify acknowledgment, or receipt of message, as part of a communications protocol. Correspondingly a negative-acknowledgement (NAK or NACK) is a signal that is sent to reject a previously received message or to indicate some kind of error. Acknowledgments and negative acknowledgments inform a sender of the receiver's state so that it can adjust its own state accordingly. Acknowledgment signal types The ASCII code point for ACK is 0x06 (binary 0000 0110). By convention a receiving device sends an ACK to indicate it successfully received a message. ASCII also provides a NAK code point (0x15, binary 0001 0101) which can be used to indicate the receiving device cannot, or will not, comply with the message. Unicode provides visible symbols for these ASCII characters, U+2406 (␆) and U+2415 (␕). ACK and NAK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VTAM
Virtual Telecommunications Access Method (VTAM) is the IBM subsystem that implements Systems Network Architecture (SNA) for mainframe environments. VTAM provides an application programming interface (API) for communication applications, and controls communication equipment such as adapters and controllers. In modern terminology, VTAM provides a communication stack and device drivers. History VTAM was introduced in 1974 after a series of delays as a major component of SNA along with the 370x Network Control Program (NCP) and Synchronous Data Link Control (SDLC). In IBM terminology, VTAM is an access method software allowing application programs to read and write data to and from external devices. It is called 'virtual' because it was introduced at the time when IBM was introducing virtual storage by upgrading the operating systems of the System/360 series to virtual storage versions. VTAM was supposed to be the successor to the older telecommunications access methods, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Access Method
Telecommunications Access Method (TCAM) is an access method, in IBM's OS/360 and successors computer operating systems on IBM System/360 and later, that provides access to terminals units within a teleprocessing network. Features TCAM provides similar functionality to QTAM, which it replaced. It was the access method for the initial version of Time Sharing Option (TSO). With the advent of IBM's SNA, TCAM was eventually superseded by VTAM. TCAM was said to have the following enhancements over QTAM: * Improved buffering, with more buffering options. * Improved organization of message queuing on disk including multiple volume support. * Back-up copies of messages maintained on disk. * Improved testing and debugging including off-line testing, improved debugging, online terminal testing, and logging. * Improved line handling for inquiry applications. * "Significantly increases speed and efficiency over QTAM." * Improved operator monitoring and control. * Binary Synchronous Suppor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QTAM
Queued Telecommunications Access Method (QTAM) is an IBM System/360 communications access method incorporating built-in Message queue, queuing. QTAM was an alternative to the lower level Basic Telecommunications Access Method (BTAM). History QTAM was announced by IBM in 1965 as part of OS/360 and successors, OS/360 and DOS/360 and successors, DOS/360 aimed at inquiry and data collection. As announced it also supported remote job entry (RJE) applications, called ''job processing'', which was dropped by 1968. Originally QTAM supported the IBM 1030 Data Collection System, IBM 1050 Data Communications System, the IBM 1060 Data Communications System, the IBM 2671 Paper Tape Reader, AT&T 83B2 Selective Calling Stations, Western Union Plan 115A Outstations, and AT&T Teletype Model 33 or 35 Teletypewriters. By 1968 terminal support had expanded to include the IBM 2260 display complex, and the IBM 2740 communications terminal. QTAM devices were attached to a System/360 multiplexor chann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BTAM
Basic Telecommunications Access Method (BTAM) is a low-level programming interface specified by IBM for use on the IBM System/360 for start-stop and binary synchronous telecommunications terminals. Later, IBM specified higher-level interfaces QTAM and TCAM. BTAM was superseded by VTAM for Systems Network Architecture (SNA) devices. BTAM continued to be supported in later iterations of the system architecture, and IBM finally withdrew support in 2000. BTAM requires the application program or transaction processing system to handle almost every detail of the protocol. This is harder than using a higher-layer protocol, but it permits interfacing to non-standard devices in non-standard ways. An access method for terminals BTAM is an access method for interactively communicating with remote terminals, usually connected through a front end processor such as a 270x communications controller, although support for local channel-attached 3270 terminals is included. BTAM dynamically bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Methods
Access may refer to: Companies and organizations * ACCESS (Australia), an Australian youth network * Access (credit card), a former credit card in the United Kingdom * Access Co., a Japanese software company * Access International Advisors, a hedge fund * AirCraft Casualty Emotional Support Services * Arab Community Center for Economic and Social Services * Access, the Alphabet division containing Google Fiber * Access, the Southwest Ohio Regional Transit Authority's paratransit service Sailing * Access 2.3, a sailing keelboat * Access 303, a sailing keelboat * Access Liberty, a sailing keelboat Television * '' Access Hollywood'', formerly ''Access'', an American entertainment newsmagazine * ''Access'' (British TV programme), a British entertainment television programme * ''Access'' (Canadian TV series), a Canadian television series (1974–1982) * Access TV, a former Canadian educational television channel (1973–2011) * Access Television Network, an American infom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohawk Data Sciences
Mohawk Data Sciences Corporation (MDS) was an early computer hardware company, started by former Univac engineers in 1964; by 1985 they were struggling to sell off part of their company. History The company was founded in Herkimer, New York, by George Cogar, Lauren King, and Ted Robinson, former Univac employees. Their success in selling their first product, a Key-to-Tape Data Entry device that allowed doing away with Keypunch devices, brought them enough cash to also grow via acquisition. Among their acquisitions was Atron Corporation, developer of a minicomputer, the Atron 501 and 502. From the know-how acquired and absorbed, Mohawk expanded into the areas of controlling line printers and also Remote Job Entry (RJE). This was the basis of their MDS 2400 RJE product, which supported 2780 and HASP. Another major acquisition was Anelex Corporation of Boston, at the time the second-largest manufacturer of printers behind IBM and an early entrant in the hard disk drive mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 3780
The IBM 2780 and the IBM 3780 are devices developed by IBM for performing remote job entry (RJE) and other batch functions over telephone lines; they communicate with the mainframe via Binary Synchronous Communications (BSC or Bisync) and replaced older terminals using synchronous transmit-receive (STR). In addition, IBM has developed workstation programs for the 1130, 360/20, 2922, System/360 other than 360/20, System/370 and System/3. 2780 Data Transmission Terminals The 2780 Data Transmission Terminal first shipped in 1967. It consists of: * A line printer similar to the IBM 1443 that can print up to 240 lines per minute (lpm), or 300 lpm using an extremely restricted character set. * A card reader/punch unit, similar to an IBM 1442, that can read up to 400 cards per minute (cpm) and can punch up to 355 cpm. * A line buffer that stores data received or to be transmitted over the communications line. * A binary synchronous adapter which controls the flow of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote Job Entry
Remote job entry, or Remote Batch, is the procedure for sending requests for non-interactive data processing tasks ( jobs) to mainframe computers from remote workstations, and by extension the process of receiving the output from such jobs at a remote workstation. The RJE workstation is called a remote because it usually is located some distance from the host computer. The workstation connects to the host through a modem, digital link, packet-switching network or local area network (LAN). RJE is similar to uux and SSH, except that the workstation sends a complete job stream rather than a single command and that the user does not receive any output until the completion of the job.. The terms Remote Batch, Remote Job System and Remote Job Processing are also used for RJE facilities. Examples Remote Job Entry (RJE) is also the name of an OS/360 component that provided RJE services. An RJE workstation operator may have complete console control of the job flow between the workstat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainframe Computer
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, server (computing), servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers. The term ''mainframe'' was derived from the large cabinet, called a ''main frame'', that housed the central processing unit and main computer memory, memory of early computers. Later, the term ''mainframe'' was used to distinguish high-end commercial computers from less powerful machines. Design Modern mainfr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
