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Bus And Tag
Bus and Tag is an "IBM standard for a computer peripheral interface", and was commonly used to connect their mainframe computers to peripheral devices such as line printers, disk storage, magnetic tape drives and IBM 3270 display controllers. The technology uses two sets of thick, multi-connector copper cables, one set, carrying data, called the ''bus'', and the other set, carrying control information, called the ''tag''. Bus and Tag cables are " daisy chained"; and one interface can attach up to eight peripheral control units. The last control unit in the chain must have a terminator plug. Each control unit can attach a maximum number of devices, "sixteen is a typical number." There is an architectural limit of 256 devices per channel, and initially a limitation of , later extended to , between the mainframe and the control unit. Bus and Tag channels handle data rates up to 4.5 MB per second. Only one device can transfer data at a time. Bus and Tag architecture was als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Communication
In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels. Serial communication is used for all long-haul communication and most computer networks, where the cost of cable and synchronization difficulties make parallel communication impractical. Serial computer buses are becoming more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express is an example. Cables Many serial communication systems were originally designed to transfer data over relatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 2305
IBM manufactured magnetic disk storage devices from 1956 to 2003, when it sold its hard disk drive business to Hitachi. Both the hard disk drive (HDD) and floppy disk drive (FDD) were invented by IBM and as such IBM's employees were responsible for many of the innovations in these products and their technologies. The basic mechanical arrangement of hard disk drives has not changed since the IBM 1301. Disk drive performance and characteristics are measured by the same standards now as they were in the 1950s. Few products in history have enjoyed such spectacular declines in cost and physical size along with equally dramatic improvements in capacity and performance. IBM manufactured 8-inch floppy disk drives from 1969 until the mid-1980s, but did not become a significant manufacturer of smaller-sized, 5.25- or 3.5-inch floppy disk drives (the dimension refers to the diameter of the floppy disk, not the size of the drive). IBM always offered its magnetic disk drives for sale but did ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
360/195
The IBM System/360 Model 195 is a discontinued IBM computer introduced on August 20, 1969. The Model 195 was a reimplementation of the IBM System/360 Model 91 design using monolithic integrated circuits. It offers "an internal processing speed about twice as fast as the Model 85, the next most powerful System/360". The Model 195 was discontinued on February 9, 1977, the same date as the System/370 Model 195. About 20 Model 195 systems were produced. Technical specifications The basic CPU cycle time is 54 nanoseconds (ns). The system has a high degree of parallelism and can process up to seven operations at a time. The system can be configured with 1, 2, or 4 MB of magnetic core memory (models 195J, 195K, and 195L) with a cycle time of 756 ns. A 32 KB cache, called a ''buffer memory'' in the IBM announcement, is standard. Memory blocks are brought into cache in units of 64 bytes. The normal operating system for the Model 195 is OS/360 Multiprogramming with a Va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
360/85
The IBM System/360 Model 85 is a high-end member of the System/360 family of computers, with many advanced features, and was announced in January 1968 and first shipped in December 1969. IBM built only about 30 360/85 systems because of "a recession in progress". Models The four models of the 360/85 are: I85 (512K), J85 (1M), K85 (2M) and L85 (4M), configured with two IBM 2365 Processor Storage units, four 2365 units, an IBM 2385 Processor Storage unit Model 1 (=2M), or an IBM 2385 Processor Storage unit Model 2 (=4M) respectively. The I85 includes two-way interleaved memory while the others provide four-way interleaving of memory access. Advanced/special features * The system console is L-shaped: one leg is the Main Control Panel, including a CRT, and the other leg includes 2 screens: "Microfiche Document Viewer" and "Indicator Viewer." * Memory Cache - depending on the model and the situation, "the effective system storage cycle becomes one-third to one-fourth of the actu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
FICON
FICON (Fibre Connection) is the IBM proprietary name for the ANSI ''FC-SB-3 Single-Byte Command Code Sets-3 Mapping Protocol'' for Fibre Channel (FC) protocol. It is a FC layer 4 protocol used to map both IBM's antecedent (either ESCON or parallel Bus and Tag) channel-to-control-unit cabling infrastructure and protocol onto standard FC services and infrastructure. The topology is fabric utilizing FC switches or directors. Valid rates include 1, 2, 4, 8 and 16 Gigabit per second data rates at distances up to 100 km. FICON was introduced in 1998 as part of fifth generation of IBM System/390 mainframes. After 2011 FICON replaced ESCON in new IBM mainframe deployments because of FICON's technical superiority (especially its higher performance) and lower cost. Protocol internals Each FICON channel port is capable of multiple concurrent data exchanges (a maximum of 32) in full duplex mode. Information for active exchanges is transferred in Fibre Channel sequences mapped as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESCON
ESCON (Enterprise Systems Connection) is a data connection created by IBM, and is commonly used to connect their mainframe computers to peripheral devices such as disk storage, tape drives and IBM 3270 display controllers. ESCON is an optical fiber, half-duplex, serial interface. It originally operated at a rate of 10MB/s, which was later increased to 17MB/s. The current maximum distance is 43 kilometers. IBM introduced ESCON in September 1990 as part of its System/390 announcement. It replaced the older, slower (4.5MB/s), copper-based, parallel, IBM System/360 Bus and Tag channels technology of 1960-1990 era mainframes. Optical fiber is smaller in diameter and weight, and hence could save installation costs. Space and labor could also be reduced when fewer physical links were required - due to ESCON's switching features. ESCON is being supplanted by the substantially faster FICON, which runs over Fibre Channel. ESCON allows the establishment and reconfiguration of ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiber Optic
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers. Op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System/370
The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the product announcement. In September 1990, the System/370 line was replaced with the System/390. Evolution The original System/370 line was announced on June 30, 1970, with first customer shipment of the Models 155 and 165 planned for February 1971 and April 1971 respectively. The 155 first shipped in January 1971. System/370 underwent several architectural improvements during its roughly 20-year lifetime. The following features mentioned in Principles of Operation are either optional on S/360 but standard on S/370, introduced with S/370 or added to S/370 after announcement. *Branch and Save *Channel Indirect Data Addressing *Channel-Set Switching *Clear I/O *Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Printer
A line printer prints one entire line of text before advancing to another line. Most early line printers were impact printers. Line printers are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use. Print speeds of 600 lines per minute (approximately 10 pages per minute) were achieved in the 1950s, later increasing to as much as 1200 lpm. Line printers print a complete line at a time and have speeds in the range of 150 to 2500 lines per minute. The types of line printers are drum printers, band-printers, and chain printers. Other non-impact technologies have also been used, as thermal line printers were popular in the 1970s and 1980s, and some inkjet and laser printers produce output a line or a page at a time. Designs Many impact printers, such as the daisywheel printer and dot matrix printer, used a print head that printed a character then moved on until an entire line was printed. Line printers we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 IBM System/360 Model 30, Model 30, could perform up to 34,500 instructions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
