|
Supervisor Mode
In computer science, hierarchical protection domains, often called protection rings, are mechanisms to protect data and functionality from faults (by improving fault tolerance) and malicious behavior (by providing computer security). Computer operating systems provide different levels of access to resources. A protection ring is one of two or more hierarchical ''levels'' or ''layers'' of privilege within the architecture of a computer system. This is generally hardware-enforced by some CPU architectures that provide different CPU modes at the hardware or microcode level. Rings are arranged in a hierarchy from most privileged (most trusted, usually numbered zero) to least privileged (least trusted, usually with the highest ring number). Ring 0 is the level with the most privileges and allows direct interaction with the physical hardware such as certain CPU functionality and chips on the motherboard. Special call gates between rings are provided to allow an outer ring to ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priv Rings
The BlackBerry Priv is a slider smartphone developed by BlackBerry Limited. Following a series of leaks, it was officially announced by BlackBerry CEO John Chen on September 25, 2015, with pre-orders opening on October 23, 2015, for a release on November 6, 2015. The Priv is the first BlackBerry-branded smartphone that does not run the company's proprietary BlackBerry OS or BlackBerry 10 (BB10) platforms. It instead uses Android, customized with features inspired by those on BlackBerry phones, and security enhancements. With its use of Android—one of two smartphone platforms that significantly impacted BlackBerry's early dominance in the smartphone industry—the company sought to leverage access to the larger ecosystem of software available through the Google Play Store (as opposed to BlackBerry 10 devices, which were limited to native BB10 apps from BlackBerry World and Android apps from the third-party Amazon Appstore running in a compatibility subsystem), in combinatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honeywell 6180
The Honeywell 6000 series computers were rebadged versions of General Electric's 600-series mainframes manufactured by Honeywell International, Inc. from 1970 to 1989. Honeywell acquired the line when it purchased GE's computer division in 1970 and continued to develop them under a variety of names for many years. The high-end model was the 6080, with performance approximately 1 MIPS. Smaller models were the 6070, 6060, 6050, 6040, and 6030. In 1973 a low-end 6025 was introduced. The even-numbered models included an ''Enhanced Instruction Set'' feature (EIS), which added decimal arithmetic and storage-to-storage operations to the original word-oriented architecture. In 1973 Honeywell introduced the 6180, a 6000-series machine with addressing modifications to support the Multics operating system. In 1974 Honeywell released the 68/80 which added cache memory in each processor and support for a large (2-8 million word) directly addressable memory. In 1975 the 6000-series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanenbaum–Torvalds Debate
The Tanenbaum–Torvalds debate was a written debate between Andrew S. Tanenbaum and Linus Torvalds, regarding the Linux kernel and kernel architecture in general. Tanenbaum, the creator of Minix, began the debate in 1992 on the Usenet discussion group , arguing that microkernels are superior to monolithic kernels and therefore Linux was, even in 1992, obsolete. The debate has sometimes been considered a flame war. The debate While the debate initially started out as relatively moderate, with both parties involved making only banal statements about kernel design, it grew progressively more detailed and sophisticated with every round of posts. Besides just kernel design, the debate branched into several other topics, such as which microprocessor architecture would win out over others in the future. Besides Tanenbaum and Torvalds, several other people joined the debate, including Peter MacDonald, an early Linux kernel developer and creator of one of the first distributio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a ''host machine'', and each virtual machine is called a ''guest machine''. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances (usually called ''containers'') must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenVMS
OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using OpenVMS include banks and financial services, hospitals and healthcare, telecommunications operators, network information services, and industrial manufacturers. During the 1990s and 2000s, there were approximately half a million VMS systems in operation worldwide. It was first announced by Digital Equipment Corporation (DEC) as VAX/VMS (''Virtual Address eXtension/Virtual Memory System'') alongside the VAX-11/780 minicomputer in 1977. OpenVMS has subsequently been ported to run on DEC Alpha systems, the Itanium-based HPE Integrity Servers, and select x86-64 hardware and hypervisors. Since 2014, OpenVMS is developed and supported by VMS Software Inc. (VSI). OpenVMS offers high availability through computer cluster, clustering — the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS Protected Mode Services DOS Protected Mode Services (DPMS) is a set of extended DOS memory management services to allow DPMS-enabled DOS drivers to load and execute in extended memory and protected mode. Not being a DOS extender by |
