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PSI Comp 80
The PSI Comp 80 was a home computer sold by Powertran starting in 1979. It was sold in the form of a kit of parts for a cased single-board home computer system. The system was based on a Z80 microprocessor addressing a mixture of 8 KB of system RAM and EPROM, plus 2 KB of video RAM. It used a National Semiconductor MM57109N as a mathematical co-processor to speed up calculations. History and specifications In 1979, the British magazine ''Wireless World'' published the technical details for a "Scientific Computer". Shortly afterward the British firm Powertran used this design for their implementation, which they called the PSI Comp 80. Ahead of its time, it incorporated a number crunching coprocessor and a novel language embedded in EPROM called Basic Using Reverse Polish - BURP. The monochrome Video Display Controller could simultaneously display combinations of 32 lines of 64 characters, and 128 x 64 resolution graphics by either displaying a normal character or a " pseudo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Computer
Home computers were a class of microcomputers that entered the market in 1977 and became common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single, non-technical user. These computers were a distinct market segment that typically cost much less than business, scientific, or engineering-oriented computers of the time, such as those running CP/M or the IBM PC, and were generally less powerful in terms of computer memory, memory and expandability. However, a home computer often had better video display controller, graphics and sound than contemporary business computers. Their most common uses were word processing, playing video games, and computer programming, programming. Home computers were usually sold already manufactured in stylish metal or plastic enclosures. However, some home computers also came as commercial electronic kits, like the ZX80, Sinclair ZX80, which were both h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semigraphics
Text-based semigraphics, pseudographics, or character graphics is a primitive method used in early text mode video hardware to emulate raster graphics without having to implement the logic for such a display mode. There are two different ways to accomplish the emulation of raster graphics. The first one is to create a low-resolution all points addressable mode using a set of special characters with all binary combinations of a certain subdivision matrix of the text mode character size; this method is referred to as block graphics, or sometimes mosaic graphics. The second one is to use special shapes instead of glyphs (letters and figures) that appear as if drawn in raster graphics mode, sometimes referred to as semi- or pseudo-graphics; an important example of this is box-drawing characters. Semigraphical characters (including some block elements) are still incorporated into the BIOS of any VGA compatible video card, so any PC can display these characters from the moment it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random-access Memory
Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and Magnetic tape data storage, magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. In today's technology, random-access memory takes the form of integrated circuit (IC) chips with MOSFET, MOS (metal–oxide–semiconductor) Memory cell (computing), memory cells. RAM is normally associated with Volatile memory, volatile types of memory where s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD64180
The HD64180 is a Z80-based embedded microprocessor developed by Hitachi with an integrated memory management unit (MMU) and on-chip peripherals. It appeared in 1985. The Hitachi HD64180 "Super Z80" was later licensed to Zilog and sold by them as the Z64180 and with some enhancements as the Zilog Z180. Overview The HD64180 has the following features: * Execution and bus access clock rates up to 10 MHz. * Memory Management Unit supporting 512K bytes of memory (one megabyte for the HD64180 packaged in a PLCC) * I/O space of 64K addresses * 12 new instructions including 8 bit by 8 bit integer multiply, non-destructive AND and illegal instruction trap vector * Two channel Direct Memory Access Controller (DMAC) * Programmable wait state generator * Programmable DRAM refresh * Two channel Asynchronous Serial Communication Interface (ASCI) * Two channel 16-bit Programmable Reload Timer (PRT) * 1-channel Clocked Serial I/O Port (CSI/O) * Programmable Vectored Interrupt Controller The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitachi
() is a Japanese Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1910 and headquartered in Chiyoda, Tokyo. The company is active in various industries, including digital systems, power and renewable energy, railway systems, Health care, healthcare products, and Financial system, financial systems. The company was founded as an electrical machinery manufacturing subsidiary of the Kuhara Mining Plant in Hitachi, Ibaraki by engineer Namihei Odaira in 1910. It began operating as an independent company under its current name in 1920. Hitachi is listed on the Tokyo Stock Exchange and is a key component of the Nikkei 225 and TOPIX Core30 indices. As of June 2024, it has a market capitalisation of 16.9 trillion yen, making it the fourth largest Japanese company by market value. In terms of global recognition, Hitachi was ranked 38th in the 2012 Fortune Global 500 and 129th in the 2012 Forbes Global 2000. Hitachi is a highly globalised conglomerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backplane
A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect several printed circuit boards together to make up a complete computer system. Backplanes commonly use a printed circuit board, but wire-wrapped backplanes have also been used in minicomputers and high-reliability applications. A backplane is generally differentiated from a motherboard by the lack of on-board processing and storage elements. A backplane uses plug-in cards for storage and processing. Usage Early microcomputer systems like the Altair 8800 used a backplane for the processor and expansion cards. Backplanes are normally used in preference to cables because of their greater reliability. In a cabled system, the cables need to be flexed every time that a card is added or removed from the system; this flexing eventually cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master Of Science
A Master of Science (; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree. In contrast to the Master of Arts degree, the Master of Science degree is typically granted for studies in sciences, engineering and medicine and is usually for programs that are more focused on scientific and mathematical subjects; however, different universities have different conventions and may also offer the degree for fields typically considered within the humanities and social sciences. While it ultimately depends upon the specific program, earning a Master of Science degree typically includes writing a thesis. The Master of Science degree was introduced at the University of Michigan in 1858. One of the first recipients of the degree was De Volson Wood, who was conferred a Master of Science degree at the University of Michigan in 1859. Algeria Algeria follows the Bologna Process. Australia Australian universities commonly have coursework or research-based Master o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directory (computing)
In computing, a directory is a file system cataloging structure that contains references to other computer files, and possibly other directories. On many computers, directories are known as folders or drawers, analogy, analogous to a workbench or the traditional office filing cabinet. The name derives from books like a telephone directory that lists the phone numbers of all the people living in a certain area. Files are organized by storing related files in the same directory. In a hierarchical file system (that is, one in which files and directories are organized in a manner that resembles a tree structure, tree), a directory contained inside another directory is called a subdirectory. The terms parent and child are often used to describe the relationship between a subdirectory and the directory in which it is cataloged, the latter being the parent. The top-most directory in such a filesystem, which does not have a parent of its own, is called the root directory. The freedesktop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Digital Research, Inc. CP/M is a disk operating system and its purpose is to organize files on a magnetic storage medium, and to load and run programs stored on a disk. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors. CP/M's core components are the ''Basic Input/Output System'' (BIOS), the ''Basic Disk Operating System'' (BDOS), and the ''Console Command Processor'' (CCP). The BIOS consists of drivers that deal with devices and system hardware. The BDOS implements the file system and provides system services to applications. The CCP is the command-line interpreter and provides some built-in commands. CP ... [...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] |
TRS-80
The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer developed by American company Tandy Corporation and sold through their Radio Shack stores. Launched in 1977, it is one of the earliest mass-produced and mass-marketed retail home computers. The name is an abbreviation of ''Tandy Radio Shack, Z80 [microprocessor]'', referring to its Zilog Z80 8-bit microprocessor. The TRS-80 has a full-stroke QWERTY keyboard, 4 kilobyte, KB dynamic random-access memory (DRAM) standard memory, small size and desk area, floating-point Level I BASIC language Interpreter (computing), interpreter in read-only memory (ROM), 64-character-per-line computer monitor, video monitor, and had a starting price of US$600 (equivalent to US$ in ). A cassette tape drive for program storage was included in the original package. While the software environment was stable, the cassette load/save process combined with keyboard bounce issues ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a Sampling (signal processing), sample of an original image; more samples typically provide more accurate representations of the original. The Intensity (physics), intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as RGB color model, red, green, and blue, or CMYK color model, cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''wikt:sensel, sensel'' is sometimes used), while in yet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
