Viewdata
Developer Samuel Fedida, Post Office | | |
Type | Videotex | |
---|---|---|
Launch date | 1974 | |
Platform(s) | Viewdata |
Viewdata is a
Technology
Viewdata offered a display of 40×24 characters, based on
Travel industry
As of 2015, Viewdata was still in use in the
There are a number of factors still holding up a move to a Web-based standard. Viewdata is regarded within the industry as low-cost and reliable, travel consultants have been trained to use Viewdata and would need training to book holidays on the Internet, and tour operators cannot agree on a Web-based standard.[citation needed]
Bulletin board systems
It was made in the late 1970s and early 1980s to make it easier for travel consultants to check availability and make bookings for holidays. A number of Viewdata
Keypad symbols: the sextile and the square
⌗ ⚹ | |
---|---|
Viewdata keypad symbols | |
In Unicode | U+26B9 ⚹ SEXTILE U+2317 ⌗ VIEWDATA SQUARE |
Different from | |
Different from | U+002A * ASTERISK (*, *) U+0023 # NUMBER SIGN (#) |
Viewdata uses special symbols already widely available on telephone keypads: the ⚹ "star" key and the ⌗ "square" key, as formally standardised by the International Telecommunication Union.[2] These are often treated as approximately corresponding to the ASCII asterisk (*) and number sign (#), which do not necessarily conform to the ITU specifications for the keypad symbols; the asterisk is also usually displayed smaller and raised.[3]
These symbols appear as 'Sextile' and 'Viewdata square' in the Miscellaneous Symbols and Miscellaneous Technical Unicode blocks, respectively. The sextile was added due to its use in astrology,[3] and the square had previously appeared in the BS_Viewdata character set, as a replacement for the underscore.[4]
In 2013, the German national body submitted a Unicode Technical Committee proposal to align the Unicode reference glyphs with the ITU specifications for these symbols, and annotate them as telephone keypad symbols on the code charts.[3] As of 2019[update] (Unicode 12.1), these changes have not been accepted/implemented.[5]
See also
References
- ^ a b "Proceedings of the Videotex in Europe" (PDF). 1979-07-19. Retrieved 2023-12-26.
- ^ "E.161 : Arrangement of digits, letters and symbols on telephones and other devices that can be used for gaining access to a telephone network". International Telecommunication Union. 2 February 2001. Retrieved 23 December 2019.
- ^ a b c Karl Pentzlin (28 October 2013). "Proposal to incorporate two telephony symbols into Unicode by glyph and annotation changes" (PDF). UTC L2/13-105R. Archived (PDF) from the original on 2022-10-09. Retrieved 23 December 2019.
- ISO-IR-47.
- ^ Unicode Consortium. "Miscellaneous Technical" (PDF). The Unicode Standard. Archived (PDF) from the original on 2022-10-09.
- This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22.
External links
- Definition at The Institute for Telecommunication Sciences
- Examples of existing Viewdata boards:
- NXtel (a free server, page manager and client implementation, and a public hosted service).
- Telstar Videotex Service
- Ringworld (running on the original software and hardware from the time of its original incarnation, accessed via java client)
- The Dwarfen Realm (running emulated through the web)
- Celebrating the Viewdata Revolution Including several Prestel Brochures
- vd-view A Viewtex web client for TeeFax, Telstar, CCl4 and NXTel
- vidtex An ncurses/terminal client for TeeFax, Telstar, CCl4, NXTel and others