Semi graphical characters
Encyclopedia
Semi graphical characters are characters in a font that are intended to give the impression that a system can support high resolution graphics, while in fact it cannot.

Characters such as box-drawing characters dots card symbols
Suit (cards)
In playing cards, a suit is one of several categories into which the cards of a deck are divided. Most often, each card bears one of several symbols showing to which suit it belongs; the suit may alternatively or in addition be indicated by the color printed on the card...

 like ♠ ♣ ♥ and ♦ and "graphical building block" geometric shapes such as triangles gave such systems that appearance.

One of the first systems that used such characters was the commodore PET
Commodore PET
The Commodore PET was a home/personal computer produced from 1977 by Commodore International...

 within its PETSCII
PETSCII
PETSCII , also known as CBM ASCII, is the variation of the ASCII character set used in Commodore Business Machines 's 8-bit home computers, starting with the PET from 1977 and including the VIC-20, C64, CBM-II, Plus/4, C16, C116 and C128...

 font set .

A special case of semi graphical characters are "Block Graphics", A.K.A. Text semigraphics
Text semigraphics
Text semigraphics is a primitive method used in early video hardware to emulate per pixel addressable graphics without having to implement the logic for a true "high resolution" mode....

 with which it is possible to emulate an all points addressable
All Points Addressable
All Points Addressable , in the context of a video monitor, dot matrix or any display device consisting of a pixel array, refers to an arrangement bits or cells which can be individually manipulated, as opposed to rewriting the whole array every time a pixel changes.Generally, text modes are not...

 graphics mode.

Many of these historical ideas have been adopted into modern font sets like Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

, for example geometric shapes are now part of the Unicode set.

examples of use

Examples of systems that relied heavily on semi graphical characters for their graphics are:
  • The Commodore PET
    Commodore PET
    The Commodore PET was a home/personal computer produced from 1977 by Commodore International...

     was one of the first systems to rely heavily on Semi graphical characters, to get any form of graphics on screen.
  • The Mattel Aquarius
    Mattel Aquarius
    Aquarius is a home computer designed by Radofin and released by Mattel in 1983. It features a Zilog Z80 microprocessor, a rubber chiclet keyboard, 4K of RAM, and a subset of Microsoft BASIC in ROM. It connects to a television set and uses a cassette tape recorder for secondary data storage...

     relied completely on its characterset for games, even though it was marketed through toy-shops. It never became a commercial success partly because of this limitation, which was outdated at the time.
  • The Sharp MZ
    Sharp MZ
    The Sharp MZ is a series of personal computers sold in Japan and Europe by Sharp beginning in 1978.-Overview:...

     series of computers offered no highres or programmable characters, but did have a very complete set of semi graphical characters. And so still offered many nice games
  • The Compukit UK101
    Compukit UK101
    The Compukit UK101 microcomputer was a kit clone of the Ohio Scientific Superboard II single-board computer, with a few enhancements for the UK market - notably replacing the 24×24 screen display with a more useful 48×16 layout working at UK video frequencies. The video output was black and white...

     (clone of the popular Ohio Scientific superboard) also was a very early system that relied on its great characterset.

See also

  • Box-drawing characters
  • Code page 437
    Code page 437
    IBM PC or MS-DOS code page 437 is the character set of the original IBM PC. It is also known as CP 437, OEM 437, PC-8, MS-DOS Latin US or sometimes misleadingly referred to as the OEM font, High ASCII or Extended ASCII....

  • list of home computers by video hardware
  • text mode
    Text mode
    Text mode is a kind of computer display mode in which the content of the screen is internally represented 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...

  • text semigraphics
    Text semigraphics
    Text semigraphics is a primitive method used in early video hardware to emulate per pixel addressable graphics without having to implement the logic for a true "high resolution" mode....

  • Code page 437
    Code page 437
    IBM PC or MS-DOS code page 437 is the character set of the original IBM PC. It is also known as CP 437, OEM 437, PC-8, MS-DOS Latin US or sometimes misleadingly referred to as the OEM font, High ASCII or Extended ASCII....

  • PETSCII
    PETSCII
    PETSCII , also known as CBM ASCII, is the variation of the ASCII character set used in Commodore Business Machines 's 8-bit home computers, starting with the PET from 1977 and including the VIC-20, C64, CBM-II, Plus/4, C16, C116 and C128...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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