|
System 38
The System/38 is a discontinued minicomputer and midrange computer manufactured and sold by IBM. The system was announced in 1978. The System/38 has 48-bit addressing, which was unique for the time, and a novel integrated database system. It was oriented toward a multi-user system environment. At the time, the typical system handled from a dozen to several dozen terminals. Although the System/38 failed to displace the systems it was intended to replace, its architecture served as the basis of the much more successful IBM AS/400. History The System/38 was introduced on October 24, 1978 and delivered in 1980. Developed under the code-name "Pacific", it was made commercially available in August 1979. The system offered a number of innovative features, and was designed by a number of engineers including Frank Soltis and Glenn Henry. The architecture shared many similarities with the design of the failed IBM Future Systems project, including the single-level store, the use of mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Program Facility
Control Program Facility (CPF) is the operating system of the IBM System/38. CPF represented an independendent line of development at IBM Rochester, and was unrelated to the earlier and more widely used System Support Program operating system. CPF evolved into the OS/400 operating system, which was originally known as XPF (Extended CPF). While CPF is considered to be the operating system of the System/38, much of the hardware and resource management of the platform is implemented in the System/38's Horizontal and Vertical Microcode. Description of the libraries * QGPL – general purpose library * QSYS – system library * QSPL – spooling library * QTEMP – temporary library * QSRV – system service library * QRECOVERY – system recovery library Data storage In most computers prior to the System/38, and most modern ones, data stored on disk was stored in separate logical files. When data was added to a file it was written in the sector dedicated to this, or if the sector w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-level Store
Single-level storage (SLS) or single-level memory is a computer storage term which has had two meanings. The two meanings are related in that in both, pages of memory may be in primary storage (RAM) or in secondary storage (disk), and that the physical location of a page is unimportant to a process. The term originally referred to what is now usually called virtual memory, which was introduced in 1962 by the Atlas system at the University of Manchester. In modern usage, the term usually refers to the organization of a computing system in which there are no files, only persistent objects (sometimes called segments), which are mapped into processes' address spaces (which consist entirely of a collection of mapped objects). The entire storage of the computer is thought of as a single two-dimensional plane of addresses (segment, and address within segment). The persistent object concept was first introduced by Multics in the mid-1960s, in a project shared by MIT, General Electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System/3
The IBM System/3 was an IBM midrange computer introduced in 1969, and marketed until 1985. It was produced by IBM Rochester in Minnesota as a low-end business computer aimed at smaller organizations that still used IBM 1400 series computers or unit record equipment. The first member of what IBM refers to as their "midrange" line, it also introduced the RPG II programming language. It is the first ancestor in the product line whose current version is the IBM i series and includes the highly successful AS/400. History At its launch in 1969 it was available for $1000/month — less than half cost of an IBM System/360 Model 20; the smallest member of the IBM System/360 family. Many of the original System/3 model 10 units were shipped diskless, with only the new IBM 5424 Multifunction Card Unit (MFCU) which read, punched, printed on and sorted the new, smaller 96-column punched cards introduced at the same time. IBM delivered the following models: * 1969 — IBM 5410, or System/3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Console
One meaning of system console, computer console, root console, computer operator, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the Kernel (computer science), kernel, from the init system and from the syslog, system logger. It is a physical device consisting of a keyboard and a screen, and traditionally is a text terminal, but may also be a graphical terminal. System consoles are generalized to computer terminals, which are abstracted respectively by virtual consoles and terminal emulators. Today communication with system consoles is generally done abstractly, via the standard streams (stdin, stdout, and stderr), but there may be system-specific interfaces, for example those used by the system kernel. Another, older, meaning of system console, computer console, hardware console, operator's console or simply console is a hardware component used by an operator to control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MNACTEC Keyboards (31123489535)
The National Museum of Science and Industry of Catalonia ( ca, Museu Nacional de la Ciència i de la Tècnica de Catalunya) known by its acronym (mNACTEC) is one of the three national museums of Catalonia, located in Terrassa, near Barcelona. Its mission is to showcase and promote an understanding of scientific, technical and industrial culture, and furthermore to preserve, study and present the establishment and evolution of scientific and technical advances in Catalonia, their industrial application, and above all their social implications and impact. The museum is an Anchor point on the European Route of Industrial Heritage. Building The museum is housed in the iconic ''Vapor Aymerich, Amat i Jover'' in Terrassa near Barcelona. It was designed by the Catalan architect Lluís Muncunill for Messrs Aymerich, Amat i Jover in 1909. He solved the problem of roofing the immense weaving shed with row upon row of 161 shell-shaped half arches, each with gently curving windows: this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
32-bit Computing
In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32-bit units. Compared to smaller bit widths, 32-bit computers can perform large calculations more efficiently and process more data per clock cycle. Typical 32-bit personal computers also have a 32-bit address bus, permitting up to 4 GB of RAM to be accessed; far more than previous generations of system architecture allowed. 32-bit designs have been used since the earliest days of electronic computing, in experimental systems and then in large mainframe and minicomputer systems. The first hybrid 16/32-bit microprocessor, the Motorola 68000, was introduced in the late 1970s and used in systems such as the original Apple Macintosh. Fully 32-bit microprocessors such as the Motorola 68020 and Intel 80386 were launched in the early to mid 1980s and became dominant by the early 1990s. This generation of personal computers coincided w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
64-bit Computing
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer. From the software perspective, 64-bit computing means the use of machine code with 64-bit virtual memory addresses. However, not all 64-bit instruction sets support full 64-bit virtual memory addresses; x86-64 and ARMv8, for example, support only 48 bits of virtual address, with the remaining 16 bits of the virtual address required to be all 0's or all 1's, and several 64-bit instruction sets support fewer than 64 bits of physical memory address. The term ''64-bit'' also describes a generation of computers in which 64-bit processors are the norm. 64 bits is a word size that defines certain classes of computer architecture, buses, memory, and CPUs and, by extension, the software that runs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demand Paging
In computer operating systems, demand paging (as opposed to anticipatory paging) is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it and that page is not already in memory (''i.e.'', if a page fault occurs). It follows that a process begins execution with none of its pages in physical memory, and many page faults will occur until most of a process's working set of pages are located in physical memory. This is an example of a lazy loading technique. Basic concept Demand paging follows that pages should only be brought into memory if the executing process demands them. This is often referred to as lazy evaluation as only those pages demanded by the process are swapped from secondary storage to main memory. Contrast this to pure swapping, where all memory for a process is swapped from secondary storage to main memory during the process startup. Commonly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management Unit
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit having all memory references passed through itself, primarily performing the translation of virtual memory addresses to physical addresses. An MMU effectively performs virtual memory management, handling at the same time memory protection, cache control, bus arbitration and, in simpler computer architectures (especially 8-bit systems), bank switching. Overview Modern MMUs typically divide the virtual address space (the range of addresses used by the processor) into pages, each having a size which is a power of 2, usually a few kilobytes, but they may be much larger. The bottom bits of the address (the offset within a page) are left unchanged. The upper address bits are the virtual page numbers. Page table entries Most MMUs use an in-memory table of items called a "page table", containing one "page table entry" (PTE) per page, to map virtual page numbers to ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large-scale Integration
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny MOSFETs (metal–oxide–semiconductor field-effect transistors) integrate into a small chip. This results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to integrated circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs such as modern computer proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schottky TTL
A Schottky transistor is a combination of a transistor and a Schottky diode that prevents the transistor from saturating by diverting the excessive input current. It is also called a Schottky-clamped transistor. Mechanism Standard transistor-transistor logic (TTL) uses transistors as saturated switches. A saturated transistor is turned on hard, which means it has a lot more base drive than it needs for the collector current it is drawing. The extra base drive creates a stored charge in the base of the transistor. The stored charge causes problems when the transistor needs to be switched from on to off: while the charge is present, the transistor is on; all the charge must be removed before the transistor will turn off. Removing the charge takes time (called storage time), so the result of saturation is a delay between the applied turn-off input at the base and the voltage swing at the collector. Storage time accounts for a significant portion of the propagation delay in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Processing Unit
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program. This contrasts with external components such as main memory and I/O circuitry, and specialized processors such as graphics processing units (GPUs). The form, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory), decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers and other co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> System 38")
.jpg "Click for more on -> System/3")
.jpg "Click for more on -> Large-scale Integration")
