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Hack Computer
The Hack computer is a theoretical computer design created by Noam Nisan and Shimon Schocken and described in their book, ''The Elements of Computing Systems: Building a Modern Computer from First Principles.'' In using the term “modern”, the authors refer to a digital, binary machine that is patterned according to the von Neumann architecture model. The Hack computer is intended for hands-on virtual construction in a hardware simulator application as a part of a basic, but comprehensive, course in computer organization and architecture. One such course, created by the authors and delivered in two parts, is freely available as a massive open online course (MOOC) called ''Build a Modern Computer From First Principles: From Nand to Tetris''. In the twelve projects included in the course, learners start with a two input NAND gate and end up with a fully operational virtual computer, including both hardware (memory and CPU) and software (assembler, VM, Java-like programming lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory-mapped I/O
Memory-mapped I/O (MMIO) and port-mapped I/O (PMIO) are two complementary methods of performing input/output (I/O) between the central processing unit (CPU) and peripheral devices in a computer (often mediating access via chipset). An alternative approach is using dedicated I/O processors, commonly known as channels on mainframe computers, which execute their own instructions. Memory-mapped I/O uses the same address space to address both main memory and I/O devices. The memory and registers of the I/O devices are mapped to (associated with) address values, so a memory address may refer to either a portion of physical RAM or to memory and registers of the I/O device. Thus, the CPU instructions used to access the memory (e.g. ) can also be used for accessing devices. Each I/O device either monitors the CPU's address bus and responds to any CPU access of an address assigned to that device, connecting the system bus to the desired device's hardware register, or uses a dedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Mapping
Resolution independence is where elements on a computer screen are rendered at sizes independent from the pixel grid, resulting in a graphical user interface that is displayed at a consistent physical size, regardless of the resolution of the screen. Concept As early as 1978, the typesetting system TeX due to Donald Knuth introduced resolution independence into the world of computers. The intended view can be rendered beyond the atomic resolution without any artifacts, and the automatic typesetting decisions are guaranteed to be identical on any computer up to an error less than the diameter of an atom. This pioneering system has a corresponding font system, Metafont, which provides suitable fonts of the same high standards of resolution independence. The terminology device independent file format (DVI) is the file format of Donald Knuth's pioneering TeX system. The content of such a file can be interpreted at any resolution without any artifacts, even at very high resolutions n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pointer (computer Programming)
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-mapped computer hardware. A pointer ''references'' a location in memory, and obtaining the value stored at that location is known as ''dereferencing'' the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on that page. The actual format and content of a pointer variable is dependent on the underlying computer architecture. Using pointers significantly improves performance for repetitive operations, like traversing iterable data structures (e.g. strings, lookup tables, control tables, linked lists, and tree structures). In particular, it is often much cheaper in time and space to copy and deref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Register
A processor register is a quickly accessible location available to a computer's Processor (computing), processor. Registers usually consist of a small amount of fast Computer storage, storage, although some registers have specific hardware functions, and may be read-only or write-only. In computer architecture, registers are typically addressed by mechanisms other than main memory, but may in some cases be assigned a memory address e.g. DEC PDP-10, ICT 1900 series, ICT 1900. Almost all computers, whether load/store architecture or not, load items of data from a larger memory into registers where they are used for arithmetic operations, bitwise operations, and other operations, and are manipulated or tested by machine instructions. Manipulated items are then often stored back to main memory, either by the same instruction or by a subsequent one. Modern processors use either Static random-access memory, static or Dynamic random-access memory, dynamic random-access memory (RAM) as m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
