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Quark (kernel)
In computing, Quark is an operating system kernel used in MorphOS. It is a microkernel designed to run fully virtualized computers, called ''boxes'' (see sandbox). , only one ''box'' is available, the ''ABox'', that lets users run extant AmigaOS software compiled for Motorola 68000 series (MC680x0 or 68k) and PowerPC central processing units (CPUs). Design goals The Quark microkernel is not a member of the L4 microkernel family, but borrows concepts from it, including: the ''clan'' (group of tasks), ID concept, and recursive address mapping. Quark also has an asynchronous/synchronous message interface similar to Amiga's Exec kernel but adapted to an environment with memory protection. Other Quark features include: * High super/usermode switch speed * Low interrupt latency * Interrupt threads (IntThreads) and Int P-code abstraction * Symmetric multiprocessing (SMP) * Models task/thread and clan/chief * Resource tracking * Virtual memory (optional) * Distributed computing * No a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions of AmigaOS required the Motorola 68000 series of 16-bit and 32-bit microprocessors. Later versions were developed by Haage & Partner (AmigaOS 3.5 and 3.9) and then Hyperion Entertainment (AmigaOS 4.0-4.1). A PowerPC microprocessor is required for the most recent release, AmigaOS 4. AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec. It includes an abstraction of the Amiga's hardware, a disk operating system called '' AmigaDOS'', a windowing system API called ''Intuition'', and a desktop environment and file manager called ''Workbench''. The Amiga intellectual property is fragmented between Amiga Inc., Cloanto, and Hyperion Entertainment. The copyrights for works created up to 1993 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L4 Microkernel Family
L4 is a family of second-generation microkernels, used to implement a variety of types of operating systems (OS), though mostly for Unix-like, ''Portable Operating System Interface'' (POSIX) compliant types. L4, like its predecessor microkernel L3, was created by German computer scientist Jochen Liedtke as a response to the poor performance of earlier microkernel-based OSes. Liedtke felt that a system designed from the start for high performance, rather than other goals, could produce a microkernel of practical use. His original implementation in hand-coded Intel i386-specific assembly language code in 1993 sparked intense interest in the computer industry. Since its introduction, L4 has been developed to be cross-platform and to improve security, isolation, and robustness. There have been various re-implementations of the original binary L4 kernel application binary interface (ABI) and its successors, including ''L4Ka::Pistachio'' (Karlsruhe Institute of Technology), ''L4/MIPS' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trance JIT
In computing, Quark is an operating system kernel used in MorphOS. It is a microkernel designed to run fully virtualized computers, called ''boxes'' (see sandbox). , only one ''box'' is available, the ''ABox'', that lets users run extant AmigaOS software compiled for Motorola 68000 series (MC680x0 or 68k) and PowerPC central processing units (CPUs). Design goals The Quark microkernel is not a member of the L4 microkernel family, but borrows concepts from it, including: the ''clan'' (group of tasks), ID concept, and recursive address mapping. Quark also has an asynchronous/synchronous message interface similar to Amiga's Exec kernel but adapted to an environment with memory protection. Other Quark features include: * High super/usermode switch speed * Low interrupt latency * Interrupt threads (IntThreads) and Int P-code abstraction * Symmetric multiprocessing (SMP) * Models task/thread and clan/chief * Resource tracking * Virtual memory (optional) * Distributed co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Component Interconnect
Peripheral Component Interconnect (PCI) is a local computer bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format that is independent of any given processor's native bus. Devices connected to the PCI bus appear to a bus master to be connected directly to its own bus and are assigned addresses in the processor's address space. It is a parallel bus, synchronous to a single bus clock. Attached devices can take either the form of an integrated circuit fitted onto the motherboard (called a ''planar device'' in the PCI specification) or an expansion card that fits into a slot. The PCI Local Bus was first implemented in IBM PC compatibles, where it displaced the combination of several slow Industry Standard Architecture (ISA) slots and one fast VESA Local Bus (VLB) slot as the bus configuration. It has subsequently been adopted for other computer types. Typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amiga Zorro II
Zorro II is the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. The expansion slots use a 100-pin connector and the card form factor is the same as the IBM PC. Zorro II cards implement the Autoconfig protocol for automatic address space assignment (similar to the later PCI technology on the PC). The prototype "Zorro bus" expansion box for the Amiga 1000 was the basis for the initial Amiga 2000-A model design. This box connected to the Amiga 1000 unbuffered CPU bus card edge connector. Zorro II was succeeded by Zorro III, a 32-bit, asynchronous bus. Memory map External links Amiga Hardware Database- Descriptions and photos of Zorro II cards.Discussion about speed of Zorro Zorro II Zorro II is the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardware Abstraction Layer
Hardware abstractions are sets of routines in software that provide programs with access to hardware resources through programming interfaces. The programming interface allows all devices in a particular class ''C'' of hardware devices to be accessed through identical interfaces even though ''C'' may contain different subclasses of devices that each provide a different hardware interface. Hardware abstractions often allow programmers to write device-independent, high performance applications by providing standard operating system (OS) calls to hardware. The process of abstracting pieces of hardware is often done from the perspective of a CPU. Each type of CPU has a specific instruction set architecture or ISA. The ISA represents the primitive operations of the machine that are available for use by assembly programmers and compiler writers. One of the main functions of a compiler is to allow a programmer to write an algorithm in a high-level language without having to care a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Computing
A distributed system is a system whose components are located on different computer network, networked computers, which communicate and coordinate their actions by message passing, passing messages to one another from any system. Distributed computing is a field of computer science that studies distributed systems. The components of a distributed system interact with one another in order to achieve a common goal. Three significant challenges of distributed systems are: maintaining concurrency of components, overcoming the clock synchronization, lack of a global clock, and managing the independent failure of components. When a component of one system fails, the entire system does not fail. Examples of distributed systems vary from service-oriented architecture, SOA-based systems to massively multiplayer online games to peer-to-peer, peer-to-peer applications. A computer program that runs within a distributed system is called a distributed program, and ''distributed programming' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Memory
In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very large (main) memory". The computer's operating system, using a combination of hardware and software, maps memory addresses used by a program, called '' virtual addresses'', into ''physical addresses'' in computer memory. Main storage, as seen by a process or task, appears as a contiguous address space or collection of contiguous segments. The operating system manages virtual address spaces and the assignment of real memory to virtual memory. Address translation hardware in the CPU, often referred to as a memory management unit (MMU), automatically translates virtual addresses to physical addresses. Software within the operating system may extend these capabilities, utilizing, e.g., disk storage, to provide a virtual address space that ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Tracking
In computer programming, resource management refers to techniques for managing resources (components with limited availability). Computer programs may manage their own resources by using features exposed by programming languages ( is a survey article contrasting different approaches), or may elect to manage them by a host – an operating system or virtual machine – or another program. Host-based management is known as ''resource tracking,'' and consists of cleaning up resource leaks: terminating access to resources that have been acquired but not released after use. This is known as ''reclaiming'' resources, and is analogous to garbage collection for memory. On many systems, the operating system reclaims resources after the process makes the exit system call. Controlling access The omission of releasing a resource when a program has finished using it is known as a resource leak, and is an issue in sequential computing. Multiple processes wish to access a limited resour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetric Multiprocessing
Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all input and output devices, and are controlled by a single operating system instance that treats all processors equally, reserving none for special purposes. Most multiprocessor systems today use an SMP architecture. In the case of multi-core processors, the SMP architecture applies to the cores, treating them as separate processors. Professor John D. Kubiatowicz considers traditionally SMP systems to contain processors without caches. Culler and Pal-Singh in their 1998 book "Parallel Computer Architecture: A Hardware/Software Approach" mention: "The term SMP is widely used but causes a bit of confusion. ..The more precise description of what is intended by SMP is a shared memory multiprocessor where the cost of accessing a memory location ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-code Machine
In computer programming, a p-code machine (portable code machine) is a virtual machine designed to execute ''p-code'' (the assembly language or machine code of a hypothetical central processing unit (CPU)). This term is applied both generically to all such machines (such as the Java virtual machine (JVM) and MATLAB precompiled code), and to specific implementations, the most famous being the p-Machine of the Pascal-P system, particularly the UCSD Pascal implementation, among whose developers, the ''p'' in ''p-code'' was construed to mean ''pseudo'' more often than ''portable'', thus ''pseudo-code'' meaning instructions for a pseudo-machine. Although the concept was first implemented circa 1966—as O-code for the Basic Combined Programming Language (BCPL) and P code for the language Euler—the ''term'' p-code first appeared in the early 1970s. Two early compilers generating p-code were the Pascal-P compiler in 1973, by Kesav V. Nori, Urs Ammann, Kathleen Jensen, Hans-Heinrich Nä ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computing)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. The implementation of threads and processes differs between operating systems. In Modern Operating Systems, Tanenbaum shows that many distinct models of process organization are possible.TANENBAUM, Andrew S. Modern Operating Systems. 1992. Prentice-Hall International Editions, ISBN 0-13-595752-4. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. History Threads made an early appearance under the name of "tasks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
