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360 Model 25
The IBM System/360 Model 25 is a low-end member of the IBM System/360 family. It was announced on January 3, 1968, 3 years before the IBM System/360 Model 22, as a "bridge between its old and new computing systems". History At a time when lower priced alternatives, such as service bureaus - by 1968, there were 32 such service bureaus serving the US National Institutes of Health (NIH) alone - and prior generation systems, such as the Honeywell 200, a competitor to IBM's own IBM 1401, were available, this model provided a stop-gap measure. Both the Model 25 and the Model 22, which had been marketed as entry level systems, were withdrawn on the same day, October 7, 1977. Models The Model 25 can be configured with 16K, 24K, 32K, or 48K of core memory. Characteristics The base Model 25 implements the System/360 standard and commercial instruction sets. The scientific or universal instruction sets are optional features. The Model 25 logic is built on IBM SLT modules mounted on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System/360
The IBM System/360 (S/360) is a family of mainframe computer systems announced by IBM on April 7, 1964, and delivered between 1965 and 1978. System/360 was the first family of computers designed to cover both commercial and scientific applications and a complete range of applications from small to large. The design distinguished between computer architecture, architecture and implementation, allowing IBM to release a suite of compatible designs at different prices. All but the only partially compatible IBM System/360 Model 44, Model 44 and the most expensive systems use microcode to implement the instruction set, featuring 8-bit computing, 8-bit byte addressing and fixed-point binary, fixed-point decimal and IBM hexadecimal floating-point, hexadecimal floating-point arithmetic, 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. System/36 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1403
The IBM 1403 line printer was introduced as part of the IBM 1401 computer in 1959 and had an especially long life in the IBM product line. Description The original model can print 600 lines of text per minute and can skip blank lines at up to 75 inches per second (190 cm/s), while the model 3 can print at up to 1400 lines per minute. The standard model has 120 print positions. An additional 12 positions are available as an option. A print chain with up to 15 copies of the character set spins horizontally in front of the ribbon and paper. Hammers strike the paper from behind at exactly the right moment to print a character as it goes by. In later models, the print chain is replaced by a print train; print slugs instead of being mounted on a chain are placed in a track. The 1403 chain or train contains 240 characters, however numerous duplications allow a line to be printed in less than the 0.4 s required for one full rotation. The original standard "A" chain con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COBOL
COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural, and, since 2002, object-oriented language. COBOL is primarily used in business, finance, and administrative systems for companies and governments. COBOL is still widely used in applications deployed on mainframe computers, such as large-scale batch and transaction processing jobs. Many large financial institutions were developing new systems in the language as late as 2006, but most programming in COBOL today is purely to maintain existing applications. Programs are being moved to new platforms, rewritten in modern languages, or replaced with other software. COBOL was designed in 1959 by CODASYL and was partly based on the programming language FLOW-MATIC, designed by Grace Hopper. It was created as part of a U.S. Department of Defense effort to create a portable programming language for data pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BOS/360
Basic Operating System/360 (BOS/360) was an early IBM System/360 operating system. Origin BOS was one of four System/360 Operating System versions developed by the IBM General Products Division (GPD) in Endicott, New York to fill a gap at the low end of the System/360 line when it became apparent that OS/360 was not able to run on the smallest systems. BPS (Basic Programming support) was designed to run on systems with a minimum of 8 KB of main storage and no disk. BOS was intended for disk systems with at least 8 KB and one 2311 disk drive. DOS and TOS were developed from BOS for systems with at least 16 KB and either disks (DOS) or tape drives only (TOS). BOS was released in October 1965, nearly two years before OS/360, thus BOS was the only disk based operating system available at launch for a machine that was marketed as disk based. Components BOS consisted of the following components: * Control programs: ** The supervisor. ** Job control capable of ... [...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] |
Plug Compatible
Plug compatible refers to " hardware that is designed to perform exactly like another vendor's product." The term PCM was originally applied to manufacturers who made replacements for IBM peripherals. Later this term was used to refer to IBM-compatible computers. PCM and peripherals Before the rise of the PCM peripheral industry, computing systems were either configured with peripherals designed and built by the CPU vendor, or designed to use vendor-selected rebadged devices. The first example of plug-compatible IBM subsystems were tape drives and controls offered by Telex beginning 1965. Memorex in 1968 was first to enter the IBM plug-compatible disk followed shortly thereafter by a number of suppliers such as CDC, Itel, and Storage Technology Corporation. This was boosted by the world's largest user of computing equipment in both directions. Ultimately plug-compatible products were offered for most peripherals and system main memory. PCM and computer systems A plug-compatib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1400 Series
The IBM 1400 series are second-generation (transistor) mid-range business decimal computers that IBM marketed in the early 1960s. The computers were offered to replace tabulating machines like the IBM 407. The 1400-series machines stored information in magnetic cores as variable-length character strings separated on the left by a special bit, called a "wordmark," and on the right by a "record mark." Arithmetic was performed digit-by-digit. Input and output support included punched card, magnetic tape, and high-speed line printers. Disk storage Disc or disk may refer to: * Disk (mathematics) In geometry, a disk (Spelling of disc, also spelled disc) is the region in a plane (geometry), plane bounded by a circle. A disk is said to be ''closed'' if it contains the circle that constitut ... was also available. Many members of the series could be used as independent systems, as extensions to IBM punched-card equipment, or as auxiliary equipment to other computer systems. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of IBM CKD Controllers
Beginning with its 1964 System/360 announcement, IBM's mainframes initially accessed count key data (CKD) subsystems via a channel connected to separate Storage Control Units (SCUs) with attached Direct Access Storage Devices (DASD), typically a hard disk drive. This practice continued in IBM's larger mainframes thru IBM Z; however low end systems generally used lower cost integrated attachments where the function of the SCU was combined with that of the channel, typically called an Integrated File Adapter. The System/360 selector channel was followed by the System/370 block multiplexor channel which could operate as a selector channel to allow attachment of legacy subsystems. The SCU evolved into a Director and Controller, the latter typically labelled an "A-unit" (or A-Box") with the controller and at least one DASD physically in an A-unit. An Integrated Storage Control (ISC) is a Director within the cabinet of an IBM System. A Director could attach from one to four A-un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM System/360 Model 44
The IBM System/360 Model 44 is a specialized member of the IBM System/360 family, with a variant of the System/360 computer architecture, designed for scientific computing, real-time computing, process control and numerical control (NC). The Model 44 was announced August 16, 1965 and withdrawn September 24, 1973. Architecture The base Model 44 lacks the storage-to-storage character and decimal instruction sets of a standard System/360, however an "extended instruction set" feature was available to provide the missing instructions. The machine features four unique instructions: ''Change Priority Mask'' (CHPM), ''Load PSW Special'' (LPSX), ''Read Direct Word'' (RDDW), and ''Write Direct Word'' (WRDW). The system comes with four memory sizes: E (32 KiB), F (64 KiB), G (128 KiB), and H (256 KiB), with an access time of 1 μs, which puts it closer to the Model 65 (.75 μs) than the Model 50 (2.0 μs). Storage protection is an optional feature. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I/O Channel
In computing, channel I/O is a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers. In the past, channels were generally implemented with custom devices, variously named channel, I/O processor, I/O controller, I/O synchronizer, or '' DMA controller''. Overview Many I/O tasks can be complex and require logic to be applied to the data to convert formats and other similar duties. In these situations, the simplest solution is to ask the CPU to handle the logic, but because I/O devices are relatively slow, a CPU could waste time waiting for the data from the device. This situation is called 'I/O bound'. Channel architecture avoids this problem by processing some or all of the I/O task without the aid of the CPU by offloading the work to dedicated logic. Channels are logically self-contained, with sufficient logic and working storage to handle I/O tasks. Some are powerful or flex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
