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IBM 3705 Communications Controller
The IBM 3705 Communications Controller is a simple computer which attaches to an IBM System/360 or System/370. Its purpose is to connect communication lines to the mainframe channel. It was a first communications controller of the popular IBM 37xx series. It was announced in March 1972. Designed for semiconductor memory which was not ready at the time of announcement, the 3705-I had to use 1.2 microsecond core storage; the later 3705-II uses 1.0 microsecond SRAM. Solid Logic Technology components, similar to those in S/370, were used. The 3705 normally occupies a single frame two feet wide and three feet deep. Up to three expansion frames can be attached for a theoretical capacity of 352 half-duplex lines and two independent channel adapters. The 3704 is an entry level version of the 3705 with limited features. Purpose IBM intended it to be used in three ways: # Emulation of the older IBM 2703 Communications Controller and its predecessors. The relevant software is the ''Emul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1968 CNRZ Mécanographie-2-cliche Jean Weber
The year was highlighted by protests and other unrests that occurred worldwide. Events January–February * January 5 – " Prague Spring": Alexander Dubček is chosen as leader of the Communist Party of Czechoslovakia. * January 10 – John Gorton is sworn in as 19th Prime Minister of Australia, taking over from John McEwen after being elected leader of the Liberal Party the previous day, following the disappearance of Harold Holt. Gorton becomes the only Senator to become Prime Minister, though he immediately transfers to the House of Representatives through the 1968 Higgins by-election in Holt's vacant seat. * January 15 – The 1968 Belice earthquake in Sicily kills 380 and injures around 1,000. * January 21 ** Vietnam War: Battle of Khe Sanh – One of the most publicized and controversial battles of the war begins, ending on April 8. ** 1968 Thule Air Base B-52 crash: A U.S. B-52 Stratofortress crashes in Greenland, discharging 4 nuclear bombs. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Synchronous Communications
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 backwards 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 3745
The IBM 3745 is the latest and last of a 37xx family of communications controllers for the IBM mainframe environment. As of mid-2009 there were an estimated 7,000+ of the larger 3745 models still in active production status, down from 20,000 or more in 2007. The 3745 and associated 3746 models were once heavily used within financial, insurance and retail industries as well as within government agencies globally. However, today most organizations have migrated away from the use of 3745s. IBM's Enterprise Extender and the Communication Controller for Linux on System z (CCL) have largely displaced the older 3745s. IBM announced in September 2002 that it would no longer manufacture new 3745s, but IBM continues to support the hardware by providing worldwide maintenance service, by providing microcode releases and by supporting the associated software including NCP (Network Control Program) and the virtual telecommunications access method (VTAM). IBM has announced end-of-service ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 3720
The IBM 3720 was a communications controller (front-end processor) made by IBM, suitable for use with IBM System/390. The 3720, introduced in 1986, was capable of supporting up to 60 communications lines, and was a smaller version of the 3725. Official service support was withdrawn in 1999 in favour of the IBM 3745 The IBM 3745 is the latest and last of a 37xx family of communications controllers for the IBM mainframe environment. As of mid-2009 there were an estimated 7,000+ of the larger 3745 models still in active production status, down from 20,000 or m .... The IBM 3720 is unrelated to the similarly-numbered IBM 3270 display terminal system. References External linksIBM 3720 Communication Controller Service Guide (PDF) {{mainframe-compu-stub 3720 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mbit/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s ( megabyte per second), or about 0.1192 MiB/s (mebibyte per second). The Inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPSANET
{{No footnotes, date=November 2020 IPSANET was a packet switching network written by I. P. Sharp Associates (IPSA). Operation began in May 1976. It initially used the IBM 3705 Communications Controller and Computer Automation LSI-2 computers as nodes. An Intel 80286 based-node was added in 1987. It was called the Beta node. The original purpose was to connect low-speed dumb terminals to a central time sharing host in Toronto. It was soon modified to allow a terminal to connect to an alternate host running the SHARP APL software under license. Terminals were initially either 2741-type machines based on the 14.8 characters/s IBM Selectric typewriter or 30 character/s ASCII machines. Link speed was limited to 9600 bit/s until about 1984. Other services including 2780/3780 Bisync support, remote printing, X.25 gateway and SDLC pipe lines were added in the 1978 to 1984 era. There was no general purpose data transport facility until the introduction of ''Network Shared Variable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KB/s
In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s ( megabyte per second), or about 0.1192 MiB/s (mebibyte per second). The Inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Memory Access
Direct memory access (DMA) is a feature of computer systems and allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed input/output, it is typically fully occupied for the entire duration of the read or write operation, and is thus unavailable to perform other work. With DMA, the CPU first initiates the transfer, then it does other operations while the transfer is in progress, and it finally receives an interrupt from the DMA controller (DMAC) when the operation is done. This feature is useful at any time that the CPU cannot keep up with the rate of data transfer, or when the CPU needs to perform work while waiting for a relatively slow I/O data transfer. Many hardware systems use DMA, including disk drive controllers, graphics cards, network cards and sound cards. DMA is also used for intra-chip data transfer in multi-core processors. Computers that have DMA channels can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kbit/s
In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s (megabyte per second), or about 0.1192 MiB/s ( mebibyte per second). The Inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Data Link Control
Synchronous Data Link Control (SDLC) is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture (SNA). SDLC supports multipoint links as well as error correction. It also runs under the assumption that an SNA header is present after the SDLC header. SDLC was mainly used by IBM mainframe and midrange systems; however, implementations exist on many platforms from many vendors. In the United States and Canada, SDLC can be found in traffic control cabinets. In 1975, IBM developed the first bit-oriented protocol, SDLC,PC Lube and Tune accessed 15. October 2009. from work done for IBM in the early 1970s.. This |
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