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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] |
Arithmetic Logic Unit
In computing, an arithmetic logic unit (ALU) is a Combinational logic, combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. It is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs). The inputs to an ALU are the data to be operated on, called operands, and a code indicating the operation to be performed (opcode); the ALU's output is the result of the performed operation. In many designs, the ALU also has status inputs or outputs, or both, which convey information about a previous operation or the current operation, respectively, between the ALU and external status registers. Signals An ALU has a variety of input and output net (electronics), nets, which are the electrical conductors used to convey Digital signal (electroni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hack Computer CPU Block Diagram
Hack may refer to: Arts, entertainment, and media Games * ''Hack'' (Unix video game), a 1984 roguelike video game * ''.hack'' (video game series), a series of video games by the multimedia franchise ''.hack'' Music * ''Hack'' (album), a 1990 album by Information Society Film * '' Hack!'', a 2007 film starring Danica McKellar * ''Hacked'' (film), a 2011 Bollywood thriller film * ''The Den'' (2013 film), a 2013 American film also known as ''Hacked'' Other uses in arts, entertainment, and media * Hack (comedy), a joke that is considered obvious, frequently used, or stolen * Hack (comics), a Marvel Comics Universe mutant character * ''Hack'' (radio program), an Australian current affairs program * ''Hack'' (TV series), an American television series * .hack, a Japanese multimedia franchise * Lifehacker, a weblog about life hacks and software Computing * Hack (computer science), an inelegant but effective solution to a computing problem * Hack (computer security), to gain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Register
In computing, the instruction register (IR) or current instruction register (CIR) is the part of a CPU's control unit that holds the instruction currently being executed or decoded. In simple processors, each instruction to be executed is loaded into the instruction register, which holds it while it is decoded, prepared and ultimately executed, which can take several steps. Some of the complicated processors use a pipeline of instruction registers where each stage of the pipeline does part of the decoding, preparation or execution and then passes it to the next stage for its step. Modern processors can even do some of the steps out of order as decoding on several instructions is done in parallel. Decoding the op-code in the instruction register includes determining the instruction, determining where its operands are in memory, retrieving the operands from memory, allocating processor resources to execute the command (in super scalar processors), etc. The output of the IR is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Counter
The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer, is a processor register that indicates where a computer is in its program sequence. Usually, the PC is incremented after fetching an instruction, and holds the memory address of (" points to") the next instruction that would be executed. Processors usually fetch instructions sequentially from memory, but ''control transfer'' instructions change the sequence by placing a new value in the PC. These include branches (sometimes called jumps), subroutine calls, and returns. A transfer that is conditional on the truth of some assertion lets the computer follow a different sequence under different conditions. A branch provides that the next instruction is fetched from elsewhere in memory. A subroutine call not only branches but saves the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emulator
In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device. Many printer (computing), printers, for example, are designed to emulate Hewlett-Packard, HP LaserJet printers because a significant amount of software is written specifically for HP models. If a non-HP printer emulates an HP printer, any software designed for an actual HP printer will also function on the non-HP device, producing equivalent print results. Since at least the 1990s, many video game enthusiasts and hobbyists have used emulators to play classic arcade games from the 1980s using the games' original 1980s machine code and data, which is in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Signal
In electronics and especially synchronous digital circuits, a clock signal (historically also known as ''logic beat'') is an electronic logic signal (voltage or current) which oscillates between a high and a low state at a constant frequency and is used like a metronome to synchronize actions of digital circuits. In a synchronous logic circuit, the most common type of digital circuit, the clock signal is applied to all storage devices, flip-flops and latches, and causes them all to change state simultaneously, preventing race conditions. A clock signal is produced by an electronic oscillator called a clock generator. The most common clock signal is in the form of a square wave with a 50% duty cycle. Circuits using the clock signal for synchronization may become active at either the rising edge, falling edge, or, in the case of double data rate, both in the rising and in the falling edges of the clock cycle. Digital circuits Most integrated circuits (ICs) of suffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
