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QTAM
Queued Telecommunications Access Method (QTAM) is an IBM System/360 communications access method incorporating built-in 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 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 channel through an IBM 2701 Data Adapter or IBM 2702 Transm ... [...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 With the advent of IBM's SNA, TCAM was eventually superseded by VTAM.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 Support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS/360 And Successors
Disk Operating System/360, also DOS/360, or simply DOS, is the discontinued first member of a sequence of operating systems for IBM System/360, System/370 and later mainframes. It was announced by IBM on the last day of 1964, and it was first delivered in June 1966. In its time, DOS/360 was the most widely used operating system in the world. DOS versions BOS/360 The Basic Operating System(BOS) was an early version of DOS and TOS which could provide usable functionality on a system with as little as 8 KB of main storage and one 2311 disk drive. TOS/360 TOS/360 (Tape Operating System/360, not a DOS as such and not so called) was an IBM operating system for the System/360, used in the early days around 1965 to support the System/360 Model 30 and similar platforms. TOS, as per the "Tape" in the name, required a tape drive. It shared most of the code base and some manuals with IBM's DOS/360. TOS went through 14 releases, and was discontinued when disks such as the IBM 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS/360 And Successors
OS/360, officially known as IBM System/360 Operating System, is a discontinued batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was influenced by the earlier IBSYS/IBJOB and Input/Output Control System (IOCS) packages for the IBM 7090/7094 and even more so by the PR155 Operating System for the IBM 1410/ 7010 processors. It was one of the earliestJust a few years after Atlas Supervisor, Burroughs MCP and GECOS operating systems to require the computer hardware to include at least one direct access storage device. Although OS/360 itself was discontinued, successor operating systems, including the virtual storage MVS and the 64-bit z/OS, are still run and maintain application-level compatibility with OS/360. Overview IBM announced three different levels of OS/360, generated from the same tapes and sharing most of their code. IBM eventually renamed these options and made some significant design changes: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Method
An access method is a function of a mainframe operating system that enables access to data on disk, tape or other external devices. Access methods were present in several mainframe operating systems since the late 1950s, under a variety of names; the name ''access method'' was introduced in 1963 in the IBM OS/360 operating system.M. A. Auslander, D. C. Larkin, A. L. Scherr: "The Evolution of the MVS Operating System", pages 478-479 Access methods provide an application programming interface (API) for programmers to transfer data to or from device, and could be compared to |
IBM System/360
The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applications and to cover a complete range of applications from small to large. The design distinguished between architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the only partially compatible Model 44 and the most expensive systems use microcode to implement the instruction set, which features 8-bit byte addressing and binary, decimal, and hexadecimal floating-point calculations. The System/360 family introduced IBM's Solid Logic Technology (SLT), which packed more transistors onto a circuit card, allowing more powerful but smaller computers to be built. The slowest System/360 model announced in 1964, the Model 30, could perform up to 34,500 instructions per second, with memo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teletype Model 33
The Teletype Model 33 is an electromechanical teleprinter designed for light-duty office use. It is less rugged and cost less than earlier Teletype machines. The Teletype Corporation introduced the Model 33 as a commercial product in 1963 after being originally designed for the United States Navy. There are three versions of the Model 33: * Model 33 ASR, (Automatic Send and Receive), which has a built-in eight-hole punched tape reader and tape punch; * Model 33 KSR (Keyboard Send and Receive), which lacks the paper tape reader and punch; * Model 33 RO (Receive Only) which has neither a keyboard nor a reader/punch. The Model 33 was one of the first products to employ the newly-standardized ASCII code, which was first published in 1963. A companion Model 32 used the older, more-established five-bit Baudot code. Because of its low price and ASCII-compatibility, the Model 33 was widely used with early minicomputers, and the large numbers of the teleprinter which were sold strongly i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macro (computer Science)
In computer programming, a macro (short for "macro instruction"; ) is a rule or pattern that specifies how a certain input should be mapped to a replacement output. Applying a macro to an input is known as macro expansion. The input and output may be a sequence of lexical tokens or characters, or a syntax tree. Character macros are supported in software applications to make it easy to invoke common command sequences. Token and tree macros are supported in some programming languages to enable code reuse or to extend the language, sometimes for domain-specific languages. Macros are used to make a sequence of computing instructions available to the programmer as a single program statement, making the programming task less tedious and less error-prone. (Thus, they are called "macros" because a "big" block of code can be expanded from a "small" sequence of characters.) Macros often allow positional or keyword parameters that dictate what the conditional assembler program generates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inetd
inetd (internet service daemon) is a super-server daemon on many Unix systems that provides Internet services. For each configured service, it listens for requests from connecting clients. Requests are served by spawning a process which runs the appropriate executable, but simple services such as ''echo'' are served by inetd itself. External executables, which are run on request, can be single- or multi-threaded. First appearing in 4.3BSD, it is generally located at /usr/sbin/inetd. Function Often called a super-server, inetd listens on designated ports used by Internet services such as FTP, POP3, and telnet. When a TCP packet or UDP packet arrives with a particular destination port number, inetd launches the appropriate server program to handle the connection. For services that are not expected to run with high loads, this method uses memory more efficiently, since the specific servers run only when needed. Furthermore, in inetd's "nowait" mode of service management, no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
270x
270x is a generic name for a family of IBM non-programmable communications controllers used with System/360 and System/370 computers. The family consisted of the following devices: * IBM 2701 Data Adapter Unit * IBM 2702 Transmission Control * IBM 2703 Transmission Control The 2701 and 2702 were announced simultaneously with System/360 in 1964, the 2703 was announced a year later. The 270x series was superseded by the IBM 3704 and 3705 communications controllers in 1972. 2701 The 2701 supported up to four start-stop or synchronous communications lines. It had two multiplexor channel interfaces for connection to one or two host computers. The synchronous adapter originally supported the ''Synchronous Transmit-Receive (STR)'' protocol, and later ''Binary Synchronous Communications (BISYNC)'' when it was introduced in 1967, in half duplex mode at speeds of up to 40,800 bits per second (bit/s). The 2701 could also have "data acquisition and control adapt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 2740
The IBM 2741 is a printing computer terminal that was introduced in 1965. Compared to the teletypewriter machines that were commonly used as printing terminals at the time, the 2741 offers 50% higher speed, much higher quality printing, quieter operation, interchangeable type fonts, and both upper and lower case letters. It was used primarily with the IBM System/360 series of computers, but was used with other IBM and non-IBM systems where its combination of higher speed and letter-quality output was desirable. It was influential in the development and popularity of the APL (programming language), APL programming language. It was supplanted, starting in the mid-1970s, primarily by printing terminals using Daisy wheel printing, daisy wheel mechanisms. Design The IBM 2741 combines a ruggedized IBM Selectric typewriter, Selectric typewriter mechanism with Solid Logic Technology, IBM SLT electronics and an RS-232, RS-232-C serial interface. It operates at about 14.1 characters per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 2260
The text-only monochrome IBM 2260 cathode-ray tube (CRT) video display terminal (Display Station) plus keyboard was a 1964 predecessor to the more-powerful IBM 3270 terminal line which eventually was extended to support color text and graphics. There were three models of 2260. Model 1 displayed 240 characters, formatted as six rows of forty characters. Model 2 displayed 480 characters, formatted as twelve rows of forty characters. Model 3 displayed 960 characters, formatted as twelve rows of eighty characters. A model without a keyboard was available for display-only applications. The eighty character width corresponded to IBM punch card format. The IBM 2260 and successor devices were transitional punch-card-to-CRT computer hardware that inspired many office of the future authors to write about the potential of the paperless office. The 2260 was a raster display with the unusual property that the scan lines were vertical they went from top to bottom rather than the more commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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