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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). The term ''P-code machine'' is applied generically to all such machines (such as the Java virtual machine (JVM) and MATLAB pre-compiled code), as well as specific implementations using those machines. One of the most notable uses of P-Code machines is the P-Machine of the Pascal-P system. The developers of the UCSD Pascal implementation within this system construed the ''P'' in ''P-code'' to mean ''pseudo'' more often than ''portable;'' they adopted a unique label for ''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 P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal MicroEngine
Pascal MicroEngine is a series of microcomputer products manufactured by Western Digital from 1979 through the mid-1980s, designed specifically to run the UCSD p-System efficiently. Compared to other microcomputers, which use a machine language p-code interpreter, the Pascal MicroEngine has its interpreter implemented in microcode; p-code is its machine language. The most common programming language used on the p-System is Pascal. The MicroEngine runs a special release III p-System. The enhancements of release III were incorporated into release IV which was made publicly available for other platforms but not for the MicroEngine. Products The MicroEngine series of products was offered at various levels of integration: * WD-9000 five chip microprocessor chip set * WD-900 single board computer * WD-90 packaged system * SB-1600 MicroEngine single board computer * ME-1600 Modular MicroEngine packaged system The MicroEngine chipset was based on the MCP-1600 chipset, which formed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft P-Code
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). The term ''P-code machine'' is applied generically to all such machines (such as the Java virtual machine (JVM) and MATLAB pre-compiled code), as well as specific implementations using those machines. One of the most notable uses of P-Code machines is the P-Machine of the Pascal-P system. The developers of the UCSD Pascal implementation within this system construed the ''P'' in ''P-code'' to mean ''pseudo'' more often than ''portable;'' they adopted a unique label for ''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 P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Python (programming Language)
Python is a high-level programming language, high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is type system#DYNAMIC, dynamically type-checked and garbage collection (computer science), garbage-collected. It supports multiple programming paradigms, including structured programming, structured (particularly procedural programming, procedural), object-oriented and functional programming. It is often described as a "batteries included" language due to its comprehensive standard library. Guido van Rossum began working on Python in the late 1980s as a successor to the ABC (programming language), ABC programming language, and he first released it in 1991 as Python 0.9.0. Python 2.0 was released in 2000. Python 3.0, released in 2008, was a major revision not completely backward-compatible with earlier versions. Python 2.7.18, released in 2020, was the last release of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal (programming Language)
Pascal is an imperative and procedural programming language, designed by Niklaus Wirth as a small, efficient language intended to encourage good programming practices using structured programming and data structuring. It is named after French mathematician, philosopher and physicist Blaise Pascal. Pascal was developed on the pattern of the ALGOL 60 language. Wirth was involved in the process to improve the language as part of the ALGOL X efforts and proposed a version named ALGOL W. This was not accepted, and the ALGOL X process bogged down. In 1968, Wirth decided to abandon the ALGOL X process and further improve ALGOL W, releasing this as Pascal in 1970. On top of ALGOL's scalars and arrays, Pascal enables defining complex datatypes and building dynamic and recursive data structures such as lists, trees and graphs. Pascal has strong typing on all objects, which means that one type of data cannot be converted to or interpreted as another without explicit conversions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-hosting (compilers)
In computer programming, self-hosting is the use of a program as part of the toolchain or operating system that produces new versions of that same program—for example, a compiler that can compile its own source code. Self-hosting software is commonplace on personal computers and larger systems. Other programs that are typically self-hosting include kernels, assemblers, command-line interpreters and revision control software. Operating systems An operating system is self-hosted when the toolchain to build the operating system runs on that same operating system. For example, Windows can be built on a computer running Windows. Before a system can become self-hosted, another system is needed to develop it until it reaches a stage where self-hosting is possible. When developing for a new computer or operating system, a system to run the development software is needed, but development software used to write and build the operating system is also necessary. This is called a boots ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UCSD P-System
UCSD Pascal is a Pascal (programming language), Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (UCSD). The p-System In 1977, the University of California, San Diego (UCSD) Institute for Information Systems developed UCSD Pascal to provide students with a common environment that could run on any of the then available microcomputers as well as campus Digital Equipment Corporation, DEC PDP-11 minicomputers. The operating system became known as UCSD p-System. There were three operating systems that IBM offered for its original IBM Personal Computer, IBM PC. The first was UCSD p-System, with IBM PC DOS and CP/M-86 as the other two. Vendor SofTech, SofTech Microsystems emphasized p-System's application portability, with virtual machines for 20 CPUs as of the IBM PC's release. It predicted that users would be ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Operating System (software)
The Business Operating System, or BOS, was initially developed as an early cross-platform operating system, originally for Intel 8080 and Motorola 6800 microprocessors and then for actual businesses and business models. The technology was used in Zilog Z80-based computers and later for most microcomputers of the 1980s. The system was developed by CAP Ltd, a British company that later became one of the world's largest information technology consulting firms. BOS and BOS applications were designed to be platform-independent. Via a management buyout (MBO) in 1981, BOS was spun off to three interlinked companies, MPSL (MicroProducts Software Ltd) which looked after the sales and marketing of BOS, MPPL (MicroProducts Programming Ltd) which looked after both the development of BOS and various horizontal software packages, and MicroProducts Training Ltd. BOS was distributed on a global basis, mainly to the United States and the British Commonwealth, by a variety of independent and MPSL- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machine Independence
Within computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the interpreters or run-time packages are common or standard components of all supported platforms. For example, a cross-platform application may run on Linux, macOS and Microsoft Windows. Cross-platform software may run on many platforms, or as few as two. Some frameworks for cross-platform development are Codename One, ArkUI-X, Kivy, Qt, GTK, Flutter, NativeScript, Xamarin, Apache Cordova, Ionic, and React Native. Platforms ''Platform'' can refer to the type of processor (CPU) or other hardware on which an operating system (OS) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, 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 computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Engineering
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accomplishes a task with very little (if any) insight into exactly how it does so. Depending on the system under consideration and the technologies employed, the knowledge gained during reverse engineering can help with repurposing obsolete objects, doing security analysis, or learning how something works. Although the process is specific to the object on which it is being performed, all reverse engineering processes consist of three basic steps: information extraction, modeling, and review. Information extraction is the practice of gathering all relevant information for performing the operation. Modeling is the practice of combining the gathered information into an abstract model, which can be used as a guide for designing the new object or syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Run-time Checking
Runtime error detection is a software verification method that analyzes a software application as it executes and reports defects that are detected during that execution. It can be applied during unit testing, component testing, integration testing, system testing (automated/scripted or manual), or penetration testing. Runtime error detection can identify defects that manifest themselves only at runtime (for example, file overwrites) and zeroing in on the root causes of the application crashing, running slowly, or behaving unpredictably. Defects commonly detected by runtime error detection include: * Race conditions * Exceptions * Resource leaks * Memory leaks * Security attack vulnerabilities (e.g., SQL injection) * Null pointers * Uninitialized memory * Buffer overflows Runtime error detection tools can only detect errors in the executed control flow of the application. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
