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Nukernel
NuKernel is a microkernel which was developed at Apple Computer during the early 1990s. Written from scratch and designed using concepts from the Mach 3.0 microkernel, with extensive additions for soft real-time scheduling to improve multimedia performance, it was the basis for the Copland operating system. Only one NuKernel version was released, with a Copland alpha release. Development ended in 1996 with the cancellation of Copland. The External Reference Specification (ERS) for NuKernel is contained in its entirety in its patent. The one-time technical lead for NuKernel, Jeff Robbin, was one of the leaders of iTunes and the iPod. Apple's NuKernel is not the microkernel in BeOS, nukernel. See also * XNU, the microkernel in Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copland (operating System)
Copland is an operating system developed by Apple for Macintosh computers between 1994 and 1996 but never commercially released. It was intended to be released as ''System 8'', and later, ''Mac OS 8''. Planned as a modern successor to the aging System 7, Copland introduced protected memory, preemptive multitasking, and several new underlying operating system features, while retaining compatibility with existing Mac applications. Copland's tentatively planned successor, codenamed ''Gershwin'', was intended to add more advanced features such as application-level multithreading. Development officially began in March 1994. Over the next several years, previews of Copland garnered much press, introducing the Mac audience to basic concepts of modern operating system design such as object orientation, crash-proofing, and multitasking. In May 1996, Gil Amelio stated that Copland was the primary focus of the company, aiming for a late-year release. Internally, however, the development ef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeff Robbin
Jeffrey L. Robbin is an executive and software engineer at Apple, Inc.. He developed the SoundJam music player software, which was acquired by Apple in 2000. There, he created iTunes, and was "closely involved" with the iPod's development. In 2011, ''Bloomberg'' reported that he was leading development of an Apple television set, a device rumored in Steve Jobs's autobiography. As of 2018, he led the Apple Music product and engineering teams. Early life Robbin was born in Chicago. He earned an undergraduate diploma in computer science, and later obtained an MBA. Career While pursuing an MBA, Robbin joined Apple in 1992. There, he worked on Copland, Apple's troubled operating system project, alongside fellow software engineer Bill Kincaid. Robbin and Kincaid both left Apple in early 1997; Kincaid joined a startup, while Robbin went on to create several Mac utilities which were distributed by Casady & Greene. One of these utilities was Conflict Catcher, a system extension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Computing
Real-time computing (RTC) is the computer science term for hardware and software systems subject to a "real-time constraint", for example from event to system response. Real-time programs must guarantee response within specified time constraints, often referred to as "deadlines". Ben-Ari, Mordechai; "Principles of Concurrent and Distributed Programming", ch. 16, Prentice Hall, 1990, , page 164 Real-time responses are often understood to be in the order of milliseconds, and sometimes microseconds. A system not specified as operating in real time cannot usually ''guarantee'' a response within any timeframe, although ''typical'' or ''expected'' response times may be given. Real-time processing ''fails'' if not completed within a specified deadline relative to an event; deadlines must always be met, regardless of system load. A real-time system has been described as one which "controls an environment by receiving data, processing them, and returning the results sufficiently quic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BeOS
BeOS is an operating system for personal computers first developed by Be Inc. in 1990. It was first written to run on BeBox hardware. BeOS was positioned as a multimedia platform that could be used by a substantial population of desktop users and a competitor to Classic Mac OS and Microsoft Windows. It was ultimately unable to achieve a significant market share, and did not prove commercially viable for Be Inc. The company was acquired by Palm Inc. Today BeOS is mainly used, and derivatives developed, by a small population of enthusiasts. The open-source operating system Haiku is a continuation of BeOS concepts and most of the application level compatibility. The latest version, Beta 4 released December 2022, still retains BeOS 5 compatibility in its x86 32-bit images. History Initially designed to run on AT&T Hobbit-based hardware, BeOS was later modified to run on PowerPC-based processors: first Be's own systems, later Apple Computer's PowerPC Reference Platform and Commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPod
The iPod is a discontinued series of portable media players and multi-purpose mobile devices designed and marketed by Apple Inc. The first version was released on October 23, 2001, about months after the Macintosh version of iTunes was released. Apple sold an estimated 450 million iPod products as of 2022. Apple discontinued the iPod product line on May 10, 2022. At over 20 years, the iPod brand is the oldest to be discontinued by Apple. Like other digital music players, some versions of the iPod can serve as external data storage devices. Prior to macOS 10.15, Apple's iTunes software (and other alternative software) could be used to transfer music, photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars to the devices supporting these features from computers using certain versions of Apple macOS and Microsoft Windows operating systems. Before the release of iOS 5, the iPod branding was used for the media player included with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITunes
iTunes () is a software program that acts as a media player, media library, mobile device management utility, and the client app for the iTunes Store. Developed by Apple Inc., it is used to purchase, play, download, and organize digital multimedia, on personal computers running the macOS and Windows operating systems, and can be used to rip songs from CDs, as well as play content with the use of dynamic, smart playlists. Options for sound optimizations exist, as well as ways to wirelessly share the iTunes library. Originally announced by Apple CEO Steve Jobs on January 9, 2001, iTunes' original and main focus was music, with a library offering organization and storage of Mac users' music collections. With the 2003 addition of the iTunes Store for purchasing and downloading digital music, and a version of the program for Windows, it became a ubiquitous tool for managing music and configuring other features on Apple's line of iPod media players, which extended to the iPh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Release
A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help improve the software or fix software bugs still present in the software. There are several models for such a life cycle. A common method is that suggested by Microsoft, which divides software development into five phases: Pre-alpha, Alpha, Beta, Release candidate, and Stable. Pre-alpha refers to all activities performed during the software project before formal testing. The alpha phase generally begins when the software is feature complete but likely to contain several known or unknown bugs. The beta phase generally begins when the software is deemed feature complete, yet likely to contain several known or unknown bugs. Software in the production phase will generally have many more bugs in it than completed software, as well as speed/performan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of around 74.99%. macOS by Apple Inc. is in second place (14.84%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company by market capitalization, the fourth-largest personal computer vendor by unit sales and second-largest mobile phone manufacturer. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Meta, and Microsoft. Apple was founded as Apple Computer Company on April 1, 1976, by Steve Wozniak, Steve Jobs and Ronald Wayne to develop and sell Wozniak's Apple I personal computer. It was incorporated by Jobs and Wozniak as Apple Computer, Inc. in 1977 and the company's next computer, the Apple II, became a best seller and one of the first mass-produced microcomputers. Apple went public in 1980 to instant financial success. The company developed computers featuring innovative graphical user inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed-source
Proprietary software is software that is deemed within the free and open-source software to be non-free because its creator, publisher, or other rightsholder or rightsholder partner exercises a legal monopoly afforded by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA-bound software—from making use of the software on their own, thereby restricting his or her freedoms. It is often contrasted with open-source or free software. For this reason, it is also known as non-free software or closed-source software. Types Origin Until the late 1960s computers—large and expensive mainframe computers, machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold. Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, thread management, and inter-process communication (IPC). If the hardware provides multiple rings or CPU modes, the microkernel may be the only software executing at the most privileged level, which is generally referred to as supervisor or kernel mode. Traditional operating system functions, such as device drivers, protocol stacks and file systems, are typically removed from the microkernel itself and are instead run in user space. In terms of the source code size, microkernels are often smaller than monolithic kernels. The MINIX 3 microkernel, for example, has only approximately 12,000 lines of code. History Microkernels trace their roots back to Danish computer pioneer Per Brinch Hansen and his tenure in Danish computer compan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach (kernel)
Mach () is a kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian to support operating system research, primarily distributed and parallel computing. Mach is often considered one of the earliest examples of a microkernel. However, not all versions of Mach are microkernels. Mach's derivatives are the basis of the operating system kernel in GNU Hurd and of Apple's XNU kernel used in macOS, iOS, iPadOS, tvOS, and watchOS. The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, which is a true microkernel. Mach was developed as a replacement for the kernel in the BSD version of Unix, so no new operating system would have to be designed around it. Mach and its derivatives exist within a number of commercial operating systems. These include all using the XNU operating system kernel which incorporates an earlier non-microkernel Mach as a major component. The Mach virtual memory management system was also adopted in 4.4BSD by the BSD de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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