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IBM Enterprise Systems Architecture
IBM Enterprise Systems Architecture is an instruction set architecture introduced by IBM as Enterprise Systems Architecture/370 (ESA/370) in 1988. It is based on the IBM System/370-XA architecture. It extended the dual-address-space mechanism introduced in later IBM System/370 models by adding a new mode in which general-purpose registers 1–15 are each associated with an access register referring to an address space, with instruction operands whose address is computed with a given general-purpose register as a base register will be in the address space referred to by the corresponding address register. The later Enterprise Systems Architecture/390 (ESA/390), introduced in 1990, added a facility to allow device descriptions to be read using channel commands and, in later models, added instructions to perform IEEE 754 floating-point operations and increased the number of floating-point registers from 4 to 16. Enterprise Systems Architecture is essentially a 32-bit architectu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set Architecture
In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation'' of that ISA. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Register
A control register is a processor register that changes or controls the general behavior of a CPU or other digital device. Common tasks performed by control registers include interrupt control, switching the addressing mode, paging control, and coprocessor control. History The early CPU lacked dedicated control registers, and relied on a limited set of internal signals and flags. When IBM developed a paging version of the System/360, they added 16 control registers to the design for what became the 360/67. IBM did not provide control registers on other S/360 models, but made them a standard part of System/370, although with different register and bit assignments. As IBM added new features to the architecture, e.g., DAS, S/370-XA, S/370-ESA, ESA/390, they added additional fields to the control registers. With z/Architecture, IBM doubled the control register size to 64 bits. Control registers in IBM 360/67 On the 360/67, CR0 and CR2 are used by address translation, CR 4- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing Platforms
A computing platform, digital platform, or software platform is the infrastructure on which software is executed. While the individual components of a computing platform may be obfuscated under layers of abstraction, the ''summation of the required components comprise the computing platform''. Sometimes, the most relevant layer for a specific software is called a computing platform in itself to facilitate the communication, referring to the whole using only one of its attributes – i.e. using a metonymy. For example, in a single computer system, this would be the computer's architecture, operating system (OS), and runtime libraries. In the case of an application program or a computer video game, the most relevant layer is the operating system, so it can be called a platform itself (hence the term cross-platform for software that can be executed on multiple OSes, in this context). In a multi-computer system, such as in the case of offloading processing, it would encompass bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM System/360 Mainframe Line
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is a publicly traded company and one of the 30 companies in the Dow Jones Industrial Average. IBM is the largest industrial research organization in the world, with 19 research facilities across a dozen countries; for 29 consecutive years, from 1993 to 2021, it held the record for most annual U.S. patents generated by a business. IBM was founded in 1911 as the Computing-Tabulating-Recording Company (CTR), a holding company of manufacturers of record-keeping and measuring systems. It was renamed "International Business Machines" in 1924 and soon became the leading manufacturer of punch-card tabulating systems. During the 1960s and 1970s, the IBM mainframe, exemplified by the System/360 and its successors, was the world's dominant computing platform, with the company p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
