The Amstrad CPC is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the ZX Spectrum, where it successfully established itself primarily in the United Kingdom, France, Spain, and the German-speaking parts of Europe.
In computing, multitasking is the concurrent execution of multiple tasks over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state and loading the saved state of another program and transferring control to it. This "context switch" may be initiated at fixed time intervals, or the running program may be coded to signal to the supervisory software when it can be interrupted.
A real-time operating system (RTOS) is an operating system (OS) for real-time computing applications that processes data and events that have critically defined time constraints. An RTOS is distinct from a time-sharing operating system, such as Unix, which manages the sharing of system resources with a scheduler, data buffers, or fixed task prioritization in a multitasking or multiprogramming environments. Processing time requirements need to be fully understood and bound rather than just kept as a minimum. All processing must occur within the defined constraints. Real-time operating systems are event-driven and preemptive, meaning the OS can monitor the relevant priority of competing tasks, and make changes to the task priority. Event-driven systems switch between tasks based on their priorities, while time-sharing systems switch the task based on clock interrupts.
Amstrad was a British consumer electronics company, founded in 1968 by Alan Sugar. During the 1980s, the company was known for its home computers beginning with the Amstrad CPC and later also the ZX Spectrum range after the Sinclair deal, which led it to have a substantial share of the PC market in Britain. In the following decade it shifted focus towards communication technologies, and its main business during the 2000s was the manufacture of satellite television set-top boxes for Sky, which Amstrad had started in 1989 as the then sole supplier of the emerging Sky TV service.
OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001, and was purchased again in 2013 by its current owner Microware LP.
In computing, a process is the instance of a computer program that is being executed by one or many threads. There are many different process models, some of which are light weight, but almost all processes are rooted in an operating system (OS) process which comprises the program code, assigned system resources, physical and logical access permissions, and data structures to initiate, control and coordinate execution activity. Depending on the OS, a process may be made up of multiple threads of execution that execute instructions concurrently.
MSX is a standardized home computer architecture, announced by ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, the director at ASCII Corporation. Microsoft and Nishi conceived the project as an attempt to create unified standards among various home computing system manufacturers of the period, in the same fashion as the VHS standard for home video tape machines. The first MSX computer sold to the public was a Mitsubishi ML-8000, released on October 21, 1983, thus marking its official release date.
The Amstrad PCW series is a range of personal computers produced by British company Amstrad from 1985 to 1998, and also sold under licence in Europe as the "Joyce" by the German electronics company Schneider in the early years of the series' life. The PCW, short for Personal Computer Word-processor, was targeted at the word processing and home office markets. When it was launched the cost of a PCW system was under 25% of the cost of almost all IBM-compatible PC systems in the UK, and as a result the machine was very popular both in the UK and in Europe, persuading many technophobes to venture into using computers. The series is reported to have sold 8 million units. However the last two models, introduced in the mid-1990s, were commercial failures, being squeezed out of the market by the falling prices, greater capabilities and wider range of software for IBM-compatible PCs.
In computing, scheduling is the action of assigning resources to perform tasks. The resources may be processors, network links or expansion cards. The tasks may be threads, processes or data flows.
Locomotive Basic is a proprietary dialect of the BASIC programming language written by Locomotive Software on the Amstrad CPC and the later Locomotive BASIC-2 as a GEM application on the Amstrad PC1512 and 1640. It was the main descendant of Mallard BASIC, the interpreter for CP/M supplied with the Amstrad PCW.
MultiFinder is an extension for the Apple Macintosh's classic Mac OS, introduced on August 11, 1987 and included with System Software 5. It adds cooperative multitasking of several applications at once – a great improvement over the previous Macintosh systems, which can only run one application at a time. With the advent of System 7, MultiFinder became a standard integrated part of the operating system and remained so until the introduction of Mac OS X.
The Enterprise is a Zilog Z80-based home computer announced in 1983, but due to a series of delays, was not commercially available until 1985. It was developed by British company Intelligent Software and marketed by Enterprise Computers.
TopView is the first object-oriented, multitasking, and windowing, personal computer operating environment for PC DOS developed by IBM, announced in August 1984 and shipped in March 1985. TopView provided a text-mode operating environment that allowed users to run more than one application at the same time on a PC. IBM demonstrated an early version of the product to key customers before making it generally available, around the time they shipped their new PC AT computer.
Micro-Controller Operating Systems is a real-time operating system (RTOS) designed by Jean J. Labrosse in 1991. It is a priority-based preemptive real-time kernel for microprocessors, written mostly in the programming language C. It is intended for use in embedded systems.
In computing, preemption is the act of temporarily interrupting an executing task, with the intention of resuming it at a later time. This interrupt is done by an external scheduler with no assistance or cooperation from the task. This preemptive scheduler usually runs in the most privileged protection ring, meaning that interruption and then resumption are considered highly secure actions. Such changes to the currently executing task of a processor are known as context switching.
MSX-DOS is a discontinued disk operating system developed by Microsoft's Japan subsidiary for the 8-bit home computer standard MSX, and is a cross between MS-DOS v1.25 and CP/M-80 v2.2.
An MSX-ENGINE chip is a specially developed integrated circuit for home computers that are built according to the MSX specifications. Generally, such a chip combines the functions of many separate, older/simpler chips into one. This is done to reduce required circuit board space, power consumption, and production costs for complete systems.
Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single, non-technical user. These computers were a distinct market segment that typically cost much less than business, scientific, or engineering-oriented computers of the time, such as those running CP/M or the IBM PC, and were generally less powerful in terms of memory and expandability. However, a home computer often had better graphics and sound than contemporary business computers. Their most common uses were word processing, playing video games, and programming.
