Teletext - Revision history

Arnoldemu at 17:18, 24 February 2018

2018-02-24T17:18:15Z

2012-10-29T09:12:02Z

2012-03-08T21:14:38Z

2011-08-14T15:28:09Z

‎Weblinks

2010-12-17T21:21:18Z

2010-08-14T12:22:13Z

‎Data Encoding

2010-08-14T12:21:08Z

2010-08-12T21:39:46Z

‎Pictures

2010-08-12T18:37:56Z

‎Telesoftware

2010-08-12T18:35:22Z

‎Telesoftware

@@ Line 1: / Line 1: @@
 [[Category:Network]]
-Teletext offers one-directional data transmission, broadcast via television signal.
+Teletext offers one-directional data transmission, broadcast via television signal in the unused lines at the top of the image.
 Commonly it is found in analogue television signals and contains data for text and crude graphics. Digital televisions have text services which use a different method (almost HTML based).
 Teletext is also "Mode 7" on the BBC Micro.

@@ Line 1: / Line 1: @@
 [[Category:Network]]
 Teletext offers one-directional data transmission, broadcast via television signal.
 Most commonly, Teletext decoders are built-in in (newer) television sets. Aside from that, there have been also Teletext interfaces for computers.
@@ Line 13: / Line 15: @@
 Telesoftware was as service that allowed to download computer software, encoded in Teletext pages. Although no longer supported, Telesoftware recordings '''may be still found on old VHS Video Cassettes'''.
-* '''CEEFAX''' - The British BBC CEEFAX supported Telesoftware from 1983 to 1989 (mainly for BBC computers).
+* '''CEEFAX''' - The British BBC CEEFAX supported Telesoftware from 1983 to 1989 (mainly for BBC computers). Apparently named because you can "see facts" which sounds like "Ceefax".
 * '''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).

← Older revision		Revision as of 21:14, 8 March 2012
Line 34:		Line 34:
	</gallery>		</gallery>

		+	== Advertisements ==
		+	<gallery>
		+	image:Teletext Microtext ACU ad.jpg\| Ad in [[Amstrad Computer User]]
		+	</gallery>
	== Weblinks ==		== Weblinks ==

@@ Line 36: / Line 36: @@
 == Weblinks ==
-* {{WikipediaEN|Teletext}}
+* {{EnWiki}}
 * {{WikipediaEN|Telesoftware}}
 * [http://teletext.mb21.co.uk/gallery/index.shtml Teletext Screenshots]
 * [http://teletext.mb21.co.uk/gallery/ceefax/telesoftware/ Telesoftware Screenshots]

← Older revision		Revision as of 21:21, 17 December 2010
Line 1:		Line 1:
		+	[[Category:Network]]
	Teletext offers one-directional data transmission, broadcast via television signal.		Teletext offers one-directional data transmission, broadcast via television signal.

@@ Line 18: / Line 18: @@
 == 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).
+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; which may vary from TV station to TV station).
 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).

← Older revision		Revision as of 12:21, 14 August 2010
Line 15:		Line 15:

	* '''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).		* '''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 ==		== Pictures ==

@@ Line 23: / Line 23: @@
 File:CEEFAX News.gif|CEEFAX News
 File:CEEFAX Weather.gif|CEEFAX Weather
-File:CEEFAX Telesoftware.gif|CEEFAX Telesoftware (fragment of a listing)
+File:CEEFAX Telesoftware.gif|CEEFAX Telesoftware (fragment of a file)
 File:ORACLE Farewell.gif|ORACLE Farewell
 </gallery>

@@ Line 10: / Line 10: @@
 == Telesoftware ==
-Telesoftware was as service that allowed to download computer software, encoded in Teletext pages. Although no longer supported, Telesoftware recordings '''may be still found on VHS Video Cassettes'''.
+Telesoftware was as service that allowed to download computer software, encoded in Teletext pages. Although no longer supported, Telesoftware recordings '''may be still found on old VHS Video Cassettes'''.
 * '''CEEFAX''' - The British BBC CEEFAX supported Telesoftware from 1983 to 1989 (mainly for BBC computers).

@@ Line 14: / Line 14: @@
 * '''CEEFAX''' - The British BBC CEEFAX supported Telesoftware from 1983 to 1989 (mainly for BBC computers).
-* '''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).
+* '''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).
 == Pictures ==