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Teletext

504 bytes added, 12:21, 14 August 2010
* '''ORACLE''' - The British Channel 4 ORACLE also supported Telesoftware (for different systems, including Amstrad. According to a [[:File:Volex Teletext Advert (Your Computer, March 1987).jpg|Volex Advert]], ORACLE also worked on broadcasting [[CP/M]] software).
 
== Data Encoding ==
 
Teletext transfers 360 bits (45 bytes) per scanline; at a rate of 6.9375 Mbits/s (444 times the scanline rate). Transfer is restricted to a few scanlines (during VBlank period) so the effective transfer rate is less (and depends on the number of lines being used).
 
Each byte includes a parity bit (so only 7bit per byte are actually containing usable data). The packets include some header/control bytes, and characters codes (using a variant of the standard ASCII character set).
== Pictures ==
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