|
Semigraphics
Text-based semigraphics or pseudographics 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 is turned on, even w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box-drawing Characters
Box-drawing characters, also known as line-drawing characters, are a form of semigraphics widely used in text user interfaces to draw various geometric frames and boxes. Box-drawing characters typically only work well with monospaced fonts. In graphical user interfaces, these characters are much less useful as it is more simple and appropriate to draw lines and rectangles directly with graphical APIs. However, they are still useful for command-line interfaces and plaintext comments within source code. Used along with box-drawing characters are block elements, shade characters, and terminal graphic characters, these can be used for filling regions of the screen and portraying drop shadows. Encodings Unicode Box Drawing Unicode includes 128 such characters in the Box Drawing block. In many Unicode fonts only the subset that is also available in the IBM PC character set (see below) will exist, due to it being defined as part of the WGL4 character set. The image below is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZX81
The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-cost introduction to home computing for the general public. It was hugely successful; more than 1.5 million units were sold. In the United States it was initially sold as the ZX-81 under licence by Timex. Timex later produced its own versions of the ZX81: the Timex Sinclair 1000 and Timex Sinclair 1500. Unauthorized ZX81 clones were produced in several countries. The ZX81 was designed to be small, simple, and above all, inexpensive, with as few components as possible. Video output is to a television set rather than a dedicated monitor. Programs and data are loaded and saved onto compact audio cassettes. It uses only four silicon chips and a mere 1 KB of memory. It has no power switch or moving parts, with the exception of a VHF ... [...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 launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of ''Tandy Radio Shack, Z80 icroprocessor'. It is one of the earliest mass-produced and mass-marketed retail home computers. The TRS-80 has a full-stroke QWERTY keyboard, the Zilog Z80 processor, 4 KB dynamic random-access memory (DRAM) standard memory, small size and desk area, floating-point Level I BASIC language interpreter in read-only memory (ROM), 64-character per line video monitor, and 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 and a troublesome Expansion Interface contributed to the Model I's reputation as not well-suited to serio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbols For Legacy Computing
Symbols for Legacy Computing is a Unicode block containing graphic characters that were used for various home computers from the 1970s and 1980s and in Teletext broadcasting standards. It includes characters from the Amstrad CPC, MSX, Mattel Aquarius, RISC OS, MouseText, Atari ST, TRS-80 Color Computer, Oric, Texas Instruments TI-99/4A, TRS-80, Minitel, Teletext, ATASCII, PETSCII, ZX80, and ZX81 character sets, as well as semigraphics characters. Block The image below is provided as quick reference for these symbols on systems that are unable to display them directly: : History The following Unicode-related documents record the purpose and process of defining specific characters in the Symbols for Legacy Computing block: See also * Supplemental Arrows-C Unicode block characters and * Block Elements Block Elements is a Unicode block containing square block symbols of various fill and shading. Used along with block elements are box-drawing characters, shade character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Text Mode
Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of ''character cells'', each of which contains one of the characters of a character set; at the same time, contrasted to all points addressable (APA) mode or other kinds of computer graphics modes. Text mode applications communicate with the user by using command-line interfaces and text user interfaces. Many character sets used in text mode applications also contain a limited set of predefined semi-graphical characters usable for drawing boxes and other rudimentary graphics, which can be used to highlight the content or to simulate widget or control interface objects found in GUI programs. A typical example is the IBM code page 437 character set. An important characteristic of text mode programs is that they assume monospace fonts, where every character has the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raster Graphics
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for red, green and blue. In computer graphics and digital photography, a raster graphic represents a two-dimensional picture as a rectangular matrix or grid of square pixels, viewable via a computer display, paper, or other display medium. A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel. Raster images are stored in image files with varying dissemination, production, generation, and acquisition formats. The printing and prepress industries know raster graphics as contones (from ''continuous tones''). In contrast, line art is usually implemented as vector graphics in digital systems. Many raster manipulations map directly onto the mathematical formalisms of lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poly-88
PolyMorphic Systems was a manufacturer of microcomputer boards and systems based on the S-100 bus. Their products included the Poly-88 and the System 8813. The company was incorporated in California in 1976 as Interactive Products Corporation d/b/a PolyMorphic Systems. It was initially based in Goleta, then Santa Barbara, California. S-100 boards PolyMorphic Systems' first products were several interface boards based on the then-popular S-100 bus. These were compatible with other microcomputers such as the Altair 8800 and IMSAI 8080. The first was an A/D and D/A converter board. This was followed by a video terminal interface (VTI) card which became the primary display device for their systems. Later board-level products included CPU, RAM, and disk controller cards. Poly-88 With the release of their CPU card, PolyMorphic began selling complete systems. Their first was the Poly-88, housed in a 5-slot S100 chassis, with additional side-mounted S-100 connectors for the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphic Systems (computers)
PolyMorphic Systems was a manufacturer of microcomputer boards and systems based on the S-100 bus. Their products included the Poly-88 and the System 8813. The company was incorporated in California in 1976 as Interactive Products Corporation d/b/a PolyMorphic Systems. It was initially based in Goleta, then Santa Barbara, California. S-100 boards PolyMorphic Systems' first products were several interface boards based on the then-popular S-100 bus. These were compatible with other microcomputers such as the Altair 8800 and IMSAI 8080. The first was an A/D and D/A converter board. This was followed by a video terminal interface (VTI) card which became the primary display device for their systems. Later board-level products included CPU, RAM, and disk controller cards. Poly-88 With the release of their CPU card, PolyMorphic began selling complete systems. Their first was the Poly-88, housed in a 5-slot S100 chassis, with additional side-mounted S-100 connectors for the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Gate
A logic gate is an idealized or physical device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device (see Ideal and real op-amps for comparison). Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using vacuum tubes, electromagnetic relays ( relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical elements. Now, most logic gates are made from MOSFETs (metal–oxide–semiconductor field-effect transistors). With amplification, logic gates can be cascaded in the same way that Boolean functions can be composed, allowing the construction of a physical model of all of Boolean logic, and therefore, all of the algorithms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-100 Bus
The S-100 bus or Altair bus, IEEE 696-1983 ''(withdrawn)'', is an early computer bus designed in 1974 as a part of the Altair 8800. The bus was the first industry standard expansion bus for the microcomputer industry. computers, consisting of processor and peripheral cards, were produced by a number of manufacturers. The bus formed the basis for homebrew computers whose builders (e.g., the Homebrew Computer Club) implemented drivers for CP/M and MP/M. These microcomputers ran the gamut from hobbyist toy to small business workstation and were common in early home computers until the advent of the IBM PC. Architecture The bus is a passive backplane of 100-pin printed circuit board edge connectors wired in parallel. Circuit cards measuring 5 × 10-inches serving the functions of CPU, memory, or I/O interface plugged into these connectors. The bus signal definitions closely follow those of an 8080 microprocessor system, since the Intel 8080 microprocessor was the first micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Rendered In MDA Text Mode Using Semigraphic Blocks
An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensional picture, that resembles a subject. In the context of signal processing, an image is a distributed amplitude of color(s). In optics, the term “image” may refer specifically to a 2D image. An image does not have to use the entire visual system to be a visual representation. A popular example of this is of a greyscale image, which uses the visual system's sensitivity to brightness across all wavelengths, without taking into account different colors. A black and white visual representation of something is still an image, even though it does not make full use of the visual system's capabilities. Images are typically still, but in some cases can be moving or animated. Characteristics Images may be two or three-dimensional, such as a pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attribute Clash
Attribute may refer to: * Attribute (philosophy), an extrinsic property of an object * Attribute (research), a characteristic of an object * Grammatical modifier, in natural languages * Attribute (computing), a specification that defines a property of an object, element, or file * Attribute (role-playing games), a type of statistic for a fictional character See also * Attribute clash, a display artefact on some home computers * Attribute hierarchy method The attribute hierarchy method (AHM), is a cognitively based psychometric procedure developed by Jacqueline Leighton, Mark Gierl, and Steve Hunka at the Centre for Research in Applied Measurement and Evaluation (CRAME) at the University of Alberta. ..., a cognitively based psychometric procedure * Attribution (other) * Property (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
